docs: update .all-contributorsrc [skip ci]

.circleci/config.yml

@@ -1,52 +0,0 @@
-#
-# The MIT License
-# Copyright © 2014-2021 Ilkka Seppälä
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
-#
-
-version: 2
-
-jobs:
-  sonar-pr:
-    docker:
-      - image: circleci/openjdk:11-node
-    steps:
-    - checkout
-    - restore_cache:
-        key: jdp-sonar-pr-{{ checksum "pom.xml" }}
-    - run: |
-        if [ -n "${CIRCLE_PR_NUMBER}" ]; then
-          MAVEN_OPTS="-Xmx3000m" xvfb-run ./mvnw -B clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \
-             -Dsonar.pullrequest.key=${CIRCLE_PR_NUMBER} \
-             -Dsonar.pullrequest.branch=${CIRCLE_BRANCH} \
-             -Dsonar.pullrequest.base=master
-        else
-          echo "No Sonar PR analysis as this is not a pull request"
-        fi
-    - save_cache:
-        key: jdp-sonar-pr-{{ checksum "pom.xml" }}
-        paths:
-        - ~/.m2
-
-workflows:
-  version: 2
-  all:
-    jobs:
-    - sonar-pr

.github/workflows/maven-ci.yml

@@ -40,25 +40,25 @@ jobs:
     steps:
 
     - name: Checkout Code
-      uses: actions/checkout@master
+      uses: actions/checkout@v2
       with:
         # Disabling shallow clone for improving relevancy of SonarQube reporting
         fetch-depth: 0
 
     - name: Set up JDK 11
-      uses: actions/setup-java@master
+      uses: actions/setup-java@v1
       with:
         java-version: 11
 
     - name: Cache SonarCloud packages
-      uses: actions/cache@master
+      uses: actions/cache@v2
       with:
         path: ~/.sonar/cache
         key: ${{ runner.os }}-sonar
         restore-keys: ${{ runner.os }}-sonar
 
     - name: Cache Maven dependencies
-      uses: actions/cache@master
+      uses: actions/cache@v2
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
@@ -69,6 +69,9 @@ jobs:
     - name: Install xvfb
       run: sudo apt-get install -y xvfb
 
+    # The SonarQube analysis is only for the master branch of the main repository.
+    # SonarQube scan does not work for forked repositories try changing it to xvfb-run mvn clean verify
+    # See https://jira.sonarsource.com/browse/MMF-1371
     - name: Build with Maven and run SonarQube analysis
       run: xvfb-run ./mvnw clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar
       env:

.github/workflows/maven-pr-builder.yml

@@ -29,7 +29,7 @@ name: Java PR Builder
 on:
   pull_request:
     branches: [ master ]
-    types: [ opened, reopened, synchronize ]
+    types: [ opened, reopened, synchronize, labeled, unlabeled ]
 
 jobs:
   build:
@@ -38,15 +38,15 @@ jobs:
 
     steps:
     - name: Checkout Code
-      uses: actions/checkout@master
+      uses: actions/checkout@v2
     
     - name: Set up JDK 11
-      uses: actions/setup-java@master
+      uses: actions/setup-java@v1
       with:
         java-version: 11
     
     - name: Cache Maven Dependecies
-      uses: actions/cache@master
+      uses: actions/cache@v2
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
@@ -57,5 +57,8 @@ jobs:
     - name: Install xvfb
       run: sudo apt-get install -y xvfb
     
+    # This worflow is only for building Pull Requests, the master branch runs Sonar analysis on the main repository.
+    # SonarQube scan does not work for forked repositories.
+    # See https://jira.sonarsource.com/browse/MMF-1371
     - name: Build with Maven
       run: xvfb-run ./mvnw clean verify

.mvn/wrapper/MavenWrapperDownloader.java

@@ -1,26 +1,18 @@
 /*
- * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright 2007-present the original author or authors.
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
+ *      http://www.apache.org/licenses/LICENSE-2.0
  *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  */
-
 import java.net.*;
 import java.io.*;
 import java.nio.channels.*;

arrange-act-assert/pom.xml

@@ -36,8 +36,8 @@
   <artifactId>arrange-act-assert</artifactId>
   <dependencies>
     <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
   </dependencies>

arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java

@@ -23,11 +23,11 @@
 
 package com.iluwatar.arrangeactassert;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * Arrange/Act/Assert (AAA) is a pattern for organizing unit tests. It is a way to structure your
@@ -51,11 +51,10 @@ import org.junit.jupiter.api.Test;
  * change and one reason to fail. In a large and complicated code base, tests that honor the single
  * responsibility principle are much easier to troubleshoot.
  */
-
-class CashAAATest {
+public class CashAAATest {
 
   @Test
-  void testPlus() {
+  public void testPlus() {
     //Arrange
     var cash = new Cash(3);
     //Act
@@ -65,7 +64,7 @@ class CashAAATest {
   }
 
   @Test
-  void testMinus() {
+  public void testMinus() {
     //Arrange
     var cash = new Cash(8);
     //Act
@@ -76,7 +75,7 @@ class CashAAATest {
   }
 
   @Test
-  void testInsufficientMinus() {
+  public void testInsufficientMinus() {
     //Arrange
     var cash = new Cash(1);
     //Act
@@ -87,7 +86,7 @@ class CashAAATest {
   }
 
   @Test
-  void testUpdate() {
+  public void testUpdate() {
     //Arrange
     var cash = new Cash(5);
     //Act

arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java

@@ -23,24 +23,23 @@
 
 package com.iluwatar.arrangeactassert;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * ({@link CashAAATest}) is an anti-example of AAA pattern. This test is functionally correct, but
- * with the addition of a new feature, it needs refactoring. There are an awful lot of steps in that
+ * with the addition of new feature, it needs refactoring. There are an awful lot of steps in that
  * test method, but it verifies the class' important behavior in just eleven lines. It violates the
  * single responsibility principle. If this test method failed after a small code change, it might
  * take some digging to discover why.
  */
-
-class CashAntiAAATest {
+public class CashAntiAAATest {
 
   @Test
-  void testCash() {
+  public void testCash() {
     //initialize
     var cash = new Cash(3);
     //test plus

async-method-invocation/pom.xml

@@ -45,6 +45,11 @@
 			<artifactId>mockito-core</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 	<build>
 		<plugins>

combinator/pom.xml

@@ -34,6 +34,12 @@
 
   <artifactId>combinator</artifactId>
   <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>

combinator/src/test/java/com/iluwatar/combinator/CombinatorAppTest.java

@@ -23,11 +23,11 @@
 
 package com.iluwatar.combinator;
 
+import org.junit.Test;
+
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
-import org.junit.jupiter.api.Test;
-
-class CombinatorAppTest {
+public class CombinatorAppTest {
 
   /**
    * Issue: Add at least one assertion to this test case.
@@ -37,7 +37,7 @@ class CombinatorAppTest {
    */
 
   @Test
-  void shouldExecuteApplicationWithoutException() {
+  public void shouldExecuteApplicationWithoutException() {
     assertDoesNotThrow(() -> CombinatorApp.main(new String[]{}));
   }
-}
+}

combinator/src/test/java/com/iluwatar/combinator/FinderTest.java

@@ -23,19 +23,22 @@
 
 package com.iluwatar.combinator;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.Assert;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
+import java.util.List;
 
-class FinderTest {
+import static org.junit.Assert.*;
+
+public class FinderTest {
 
   @Test
-  void contains() {
+  public void contains() {
     var example = "the first one \nthe second one \n";
 
     var result = Finder.contains("second").find(example);
-    assertEquals(1, result.size());
-    assertEquals("the second one ", result.get(0));
+    Assert.assertEquals(result.size(),1);
+    Assert.assertEquals(result.get(0),"the second one ");
   }
 
-}
+}

combinator/src/test/java/com/iluwatar/combinator/FindersTest.java

@@ -23,44 +23,44 @@
 
 package com.iluwatar.combinator;
 
-import static com.iluwatar.combinator.Finders.advancedFinder;
-import static com.iluwatar.combinator.Finders.expandedFinder;
-import static com.iluwatar.combinator.Finders.filteredFinder;
-import static com.iluwatar.combinator.Finders.specializedFinder;
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.Assert;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
+import java.util.List;
 
-class FindersTest {
+import static com.iluwatar.combinator.Finders.*;
+import static org.junit.Assert.*;
+
+public class FindersTest {
 
   @Test
-  void advancedFinderTest() {
+  public void advancedFinderTest() {
     var res = advancedFinder("it was","kingdom","sea").find(text());
-    assertEquals(1, res.size());
-    assertEquals("It was many and many a year ago,", res.get(0));
+    Assert.assertEquals(res.size(),1);
+    Assert.assertEquals(res.get(0),"It was many and many a year ago,");
   }
 
   @Test
-  void filteredFinderTest() {
+  public void filteredFinderTest() {
     var res = filteredFinder(" was ", "many", "child").find(text());
-    assertEquals(1, res.size());
-    assertEquals("But we loved with a love that was more than love-", res.get(0));
+    Assert.assertEquals(res.size(),1);
+    Assert.assertEquals(res.get(0),"But we loved with a love that was more than love-");
   }
 
   @Test
-  void specializedFinderTest() {
+  public void specializedFinderTest() {
     var res = specializedFinder("love","heaven").find(text());
-    assertEquals(1, res.size());
-    assertEquals("With a love that the winged seraphs of heaven", res.get(0));
+    Assert.assertEquals(res.size(),1);
+    Assert.assertEquals(res.get(0),"With a love that the winged seraphs of heaven");
   }
 
   @Test
-  void expandedFinderTest() {
+  public void expandedFinderTest() {
     var res = expandedFinder("It was","kingdom").find(text());
-    assertEquals(3, res.size());
-    assertEquals("It was many and many a year ago,", res.get(0));
-    assertEquals("In a kingdom by the sea,", res.get(1));
-    assertEquals("In this kingdom by the sea;", res.get(2));
+    Assert.assertEquals(res.size(),3);
+    Assert.assertEquals(res.get(0),"It was many and many a year ago,");
+    Assert.assertEquals(res.get(1),"In a kingdom by the sea,");
+    Assert.assertEquals(res.get(2),"In this kingdom by the sea;");
   }
 
 
@@ -80,4 +80,4 @@ class FindersTest {
             + "Coveted her and me.";
   }
 
-}
+}

commander/src/main/java/com/iluwatar/commander/Order.java

@@ -23,8 +23,8 @@
 
 package com.iluwatar.commander;
 
-import java.security.SecureRandom;
 import java.util.Hashtable;
+import java.util.Random;
 
 /**
  * Order class holds details of the order.
@@ -45,7 +45,7 @@ public class Order { //can store all transactions ids also
   public final String id;
   final float price;
   final long createdTime;
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
   private static final String ALL_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
   private static final Hashtable<String, Boolean> USED_IDS = new Hashtable<String, Boolean>();
   PaymentStatus paid;

commander/src/main/java/com/iluwatar/commander/Retry.java

@@ -23,10 +23,10 @@
 
 package com.iluwatar.commander;
 
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Predicate;
 
@@ -56,7 +56,7 @@ public class Retry<T> {
     void handleIssue(T obj, Exception e);
   }
 
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
 
   private final Operation op;
   private final HandleErrorIssue<T> handleError;

commander/src/main/java/com/iluwatar/commander/Service.java

@@ -24,11 +24,10 @@
 package com.iluwatar.commander;
 
 import com.iluwatar.commander.exceptions.DatabaseUnavailableException;
-
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.List;
+import java.util.Random;
 
 /**
  * Service class is an abstract class extended by all services in this example. They all have a
@@ -43,7 +42,7 @@ public abstract class Service {
 
   protected final Database database;
   public ArrayList<Exception> exceptionsList;
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
   private static final String ALL_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
   private static final Hashtable<String, Boolean> USED_IDS = new Hashtable<>();
 

double-buffer/pom.xml

@@ -36,6 +36,10 @@
     <artifactId>double-buffer</artifactId>
 
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>

double-buffer/src/test/java/com/iluwatar/doublebuffer/AppTest.java

@@ -23,14 +23,14 @@
 
 package com.iluwatar.doublebuffer;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
  * App unit test.
  */
-class AppTest {
+public class AppTest {
 
   /**
    * Issue: Add at least one assertion to this test case.
@@ -40,7 +40,7 @@ class AppTest {
    */
 
   @Test
-  void shouldExecuteApplicationWithoutException() {
+  public void shouldExecuteApplicationWithoutException() {
     assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 

double-buffer/src/test/java/com/iluwatar/doublebuffer/FrameBufferTest.java

@@ -23,19 +23,17 @@
 
 package com.iluwatar.doublebuffer;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
-
 import java.util.Arrays;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * FrameBuffer unit test.
  */
-class FrameBufferTest {
+public class FrameBufferTest {
 
   @Test
-  void testClearAll() {
+  public void testClearAll() {
     try {
       var field = FrameBuffer.class.getDeclaredField("pixels");
       var pixels = new Pixel[FrameBuffer.HEIGHT * FrameBuffer.WIDTH];
@@ -45,14 +43,14 @@ class FrameBufferTest {
       field.setAccessible(true);
       field.set(frameBuffer, pixels);
       frameBuffer.clearAll();
-      assertEquals(Pixel.WHITE, frameBuffer.getPixels()[0]);
+      Assert.assertEquals(Pixel.WHITE, frameBuffer.getPixels()[0]);
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 
   @Test
-  void testClear() {
+  public void testClear() {
     try {
       var field = FrameBuffer.class.getDeclaredField("pixels");
       var pixels = new Pixel[FrameBuffer.HEIGHT * FrameBuffer.WIDTH];
@@ -62,21 +60,21 @@ class FrameBufferTest {
       field.setAccessible(true);
       field.set(frameBuffer, pixels);
       frameBuffer.clear(0, 0);
-      assertEquals(Pixel.WHITE, frameBuffer.getPixels()[0]);
+      Assert.assertEquals(Pixel.WHITE, frameBuffer.getPixels()[0]);
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 
   @Test
-  void testDraw() {
+  public void testDraw() {
     var frameBuffer = new FrameBuffer();
     frameBuffer.draw(0, 0);
-    assertEquals(Pixel.BLACK, frameBuffer.getPixels()[0]);
+    Assert.assertEquals(Pixel.BLACK, frameBuffer.getPixels()[0]);
   }
 
   @Test
-  void testGetPixels() {
+  public void testGetPixels() {
     try {
       var field = FrameBuffer.class.getDeclaredField("pixels");
       var pixels = new Pixel[FrameBuffer.HEIGHT * FrameBuffer.WIDTH];
@@ -85,9 +83,9 @@ class FrameBufferTest {
       var frameBuffer = new FrameBuffer();
       field.setAccessible(true);
       field.set(frameBuffer, pixels);
-      assertEquals(pixels, frameBuffer.getPixels());
+      Assert.assertEquals(pixels, frameBuffer.getPixels());
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 

double-buffer/src/test/java/com/iluwatar/doublebuffer/SceneTest.java

@@ -23,19 +23,17 @@
 
 package com.iluwatar.doublebuffer;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
-
 import java.util.ArrayList;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * Scene unit tests.
  */
-class SceneTest {
+public class SceneTest {
 
   @Test
-  void testGetBuffer() {
+  public void testGetBuffer() {
     try {
       var scene = new Scene();
       var field1 = Scene.class.getDeclaredField("current");
@@ -48,14 +46,14 @@ class SceneTest {
       var field2 = Scene.class.getDeclaredField("frameBuffers");
       field2.setAccessible(true);
       field2.set(scene, frameBuffers);
-      assertEquals(frameBuffer, scene.getBuffer());
+      Assert.assertEquals(frameBuffer, scene.getBuffer());
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to access private field.");
+      Assert.fail("Fail to access private field.");
     }
   }
 
   @Test
-  void testDraw() {
+  public void testDraw() {
     try {
       var scene = new Scene();
       var field1 = Scene.class.getDeclaredField("current");
@@ -65,10 +63,10 @@ class SceneTest {
       field2.setAccessible(true);
       field2.set(scene, 1);
       scene.draw(new ArrayList<>());
-      assertEquals(1, field1.get(scene));
-      assertEquals(0, field2.get(scene));
+      Assert.assertEquals(1, field1.get(scene));
+      Assert.assertEquals(0, field2.get(scene));
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to access private field");
+      Assert.fail("Fail to access private field");
     }
   }
 }

event-asynchronous/src/main/java/com/iluwatar/event/asynchronous/EventManager.java

@@ -23,8 +23,8 @@
 
 package com.iluwatar.event.asynchronous;
 
-import java.security.SecureRandom;
 import java.util.Map;
+import java.util.Random;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
@@ -43,7 +43,7 @@ public class EventManager implements ThreadCompleteListener {
   public static final int MAX_ID = MAX_RUNNING_EVENTS;
   public static final int MAX_EVENT_TIME = 1800; // in seconds / 30 minutes.
   private int currentlyRunningSyncEvent = -1;
-  private final SecureRandom rand;
+  private final Random rand;
   private final Map<Integer, Event> eventPool;
 
   private static final String DOES_NOT_EXIST = " does not exist.";
@@ -52,7 +52,7 @@ public class EventManager implements ThreadCompleteListener {
    * EventManager constructor.
    */
   public EventManager() {
-    rand = new SecureRandom();
+    rand = new Random(1);
     eventPool = new ConcurrentHashMap<Integer, Event>(MAX_RUNNING_EVENTS);
 
   }

factory/pom.xml

@@ -38,6 +38,10 @@
   <artifactId>junit-jupiter-engine</artifactId>
   <scope>test</scope>
  </dependency>
+ <dependency>
+ <groupId>junit</groupId>
+  <artifactId>junit</artifactId>
+ </dependency>
  </dependencies>
  <build>
  <plugins>

game-loop/pom.xml

@@ -35,6 +35,11 @@
 
     <artifactId>game-loop</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

game-loop/src/main/java/com/iluwatar/gameloop/GameLoop.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.gameloop;
 
-import java.security.SecureRandom;
+import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -80,7 +80,7 @@ public abstract class GameLoop {
    */
   protected void processInput() {
     try {
-      var lag = new SecureRandom().nextInt(200) + 50;
+      var lag = new Random().nextInt(200) + 50;
       Thread.sleep(lag);
     } catch (InterruptedException e) {
       logger.error(e.getMessage());

half-sync-half-async/pom.xml

@@ -43,6 +43,11 @@
       <artifactId>mockito-core</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
   <build>
     <plugins>

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryNumbers.java

@@ -24,10 +24,10 @@
 package com.iluwatar.hexagonal.domain;
 
 import com.google.common.base.Joiner;
-import java.security.SecureRandom;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.PrimitiveIterator;
+import java.util.Random;
 import java.util.Set;
 
 /**
@@ -126,7 +126,7 @@ public class LotteryNumbers {
      * @param max the max value (inclusive)
      */
     public RandomNumberGenerator(int min, int max) {
-      randomIterator = new SecureRandom().ints(min, max + 1).iterator();
+      randomIterator = new Random().ints(min, max + 1).iterator();
     }
 
     /**

hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java

@@ -30,9 +30,9 @@ import com.iluwatar.hexagonal.domain.LotteryService;
 import com.iluwatar.hexagonal.domain.LotteryTicket;
 import com.iluwatar.hexagonal.domain.LotteryTicketId;
 import com.iluwatar.hexagonal.domain.PlayerDetails;
-import java.security.SecureRandom;
 import java.util.AbstractMap.SimpleEntry;
 import java.util.List;
+import java.util.Random;
 import java.util.stream.Collectors;
 
 /**
@@ -41,7 +41,7 @@ import java.util.stream.Collectors;
 public class SampleData {
 
   private static final List<PlayerDetails> PLAYERS;
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
 
   static {
     PLAYERS = List.of(

leader-followers/pom.xml

@@ -32,6 +32,11 @@
     </parent>
     <artifactId>leader-followers</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

leader-followers/src/main/java/com/iluwatar/leaderfollowers/App.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.leaderfollowers;
 
-import java.security.SecureRandom;
+import java.util.Random;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 
@@ -84,7 +84,7 @@ public class App {
    * Add tasks.
    */
   private static void addTasks(TaskSet taskSet) throws InterruptedException {
-    var rand = new SecureRandom();
+    var rand = new Random();
     for (var i = 0; i < 5; i++) {
       var time = Math.abs(rand.nextInt(1000));
       taskSet.addTask(new Task(time));

leader-followers/src/test/java/com/AppTest.java

@@ -23,20 +23,20 @@
 
 package com;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
-
 import com.iluwatar.leaderfollowers.App;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
  *
  * Application test
  *
  */
-class AppTest {
+public class AppTest {
 
     @Test
-    void shouldExecuteApplicationWithoutException() {
+    public void shouldExecuteApplicationWithoutException() {
         assertDoesNotThrow(() -> App.main(new String[]{}));
     }
 

leader-followers/src/test/java/com/TaskHandlerTest.java

@@ -23,23 +23,22 @@
 
 package com;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 import com.iluwatar.leaderfollowers.Task;
 import com.iluwatar.leaderfollowers.TaskHandler;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * Tests for TaskHandler
  */
-class TaskHandlerTest {
+public class TaskHandlerTest {
 
     @Test
-    void testHandleTask() throws InterruptedException {
+    public void testHandleTask() throws InterruptedException {
         var taskHandler = new TaskHandler();
         var handle = new Task(100);
         taskHandler.handleTask(handle);
-        assertTrue(handle.isFinished());
+        Assert.assertTrue(handle.isFinished());
     }
 
 }

leader-followers/src/test/java/com/TaskSetTest.java

@@ -23,31 +23,30 @@
 
 package com;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import com.iluwatar.leaderfollowers.Task;
 import com.iluwatar.leaderfollowers.TaskSet;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * Tests for TaskSet
  */
-class TaskSetTest {
+public class TaskSetTest {
 
     @Test
-    void testAddTask() throws InterruptedException {
+    public void testAddTask() throws InterruptedException {
         var taskSet = new TaskSet();
         taskSet.addTask(new Task(10));
-        assertEquals(1, taskSet.getSize());
+        Assert.assertTrue(taskSet.getSize() == 1);
     }
 
     @Test
-    void testGetTask() throws InterruptedException {
+    public void testGetTask() throws InterruptedException {
         var taskSet = new TaskSet();
         taskSet.addTask(new Task(100));
         Task task = taskSet.getTask();
-        assertEquals(100, task.getTime());
-        assertEquals(0, taskSet.getSize());
+        Assert.assertTrue(task.getTime() == 100);
+        Assert.assertTrue(taskSet.getSize() == 0);
     }
 
 }

leader-followers/src/test/java/com/WorkCenterTest.java

@@ -23,45 +23,43 @@
 
 package com;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNull;
-
 import com.iluwatar.leaderfollowers.TaskHandler;
 import com.iluwatar.leaderfollowers.TaskSet;
 import com.iluwatar.leaderfollowers.WorkCenter;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * Tests for WorkCenter
  */
-class WorkCenterTest {
+public class WorkCenterTest {
 
   @Test
-  void testCreateWorkers() {
+  public void testCreateWorkers() {
     var taskSet = new TaskSet();
     var taskHandler = new TaskHandler();
     var workCenter = new WorkCenter();
     workCenter.createWorkers(5, taskSet, taskHandler);
-    assertEquals(5, workCenter.getWorkers().size());
-    assertEquals(workCenter.getWorkers().get(0), workCenter.getLeader());
+    Assert.assertEquals(workCenter.getWorkers().size(), 5);
+    Assert.assertEquals(workCenter.getWorkers().get(0), workCenter.getLeader());
   }
 
   @Test
-  void testNullLeader() {
+  public void testNullLeader() {
     var workCenter = new WorkCenter();
     workCenter.promoteLeader();
-    assertNull(workCenter.getLeader());
+    Assert.assertNull(workCenter.getLeader());
   }
 
   @Test
-  void testPromoteLeader() {
+  public void testPromoteLeader() {
     var taskSet = new TaskSet();
     var taskHandler = new TaskHandler();
     var workCenter = new WorkCenter();
     workCenter.createWorkers(5, taskSet, taskHandler);
     workCenter.removeWorker(workCenter.getLeader());
     workCenter.promoteLeader();
-    assertEquals(4, workCenter.getWorkers().size());
-    assertEquals(workCenter.getWorkers().get(0), workCenter.getLeader());
+    Assert.assertEquals(workCenter.getWorkers().size(), 4);
+    Assert.assertEquals(workCenter.getWorkers().get(0), workCenter.getLeader());
   }
 }

marker/src/test/java/GuardTest.java

@@ -21,18 +21,18 @@
  * THE SOFTWARE.
  */
 
+import org.junit.jupiter.api.Test;
+
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-import org.junit.jupiter.api.Test;
-
 /**
  * Guard test
  */
-class GuardTest {
+public class GuardTest {
 
   @Test
-  void testGuard() {
+  public void testGuard() {
     var guard = new Guard();
     assertThat(guard, instanceOf(Permission.class));
   }

master-worker-pattern/src/main/java/com/iluwatar/masterworker/ArrayUtilityMethods.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.masterworker;
 
-import java.security.SecureRandom;
+import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -35,7 +35,7 @@ public class ArrayUtilityMethods {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(ArrayUtilityMethods.class);
 
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
 
   /**
    * Method arraysSame compares 2 arrays @param a1 and @param a2 and @return whether their values

mvnw.cmd

@@ -1,25 +1,21 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
 @REM
-@REM The MIT License
-@REM Copyright © 2014-2021 Ilkka Seppälä
-@REM
-@REM Permission is hereby granted, free of charge, to any person obtaining a copy
-@REM of this software and associated documentation files (the "Software"), to deal
-@REM in the Software without restriction, including without limitation the rights
-@REM to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-@REM copies of the Software, and to permit persons to whom the Software is
-@REM furnished to do so, subject to the following conditions:
-@REM
-@REM The above copyright notice and this permission notice shall be included in
-@REM all copies or substantial portions of the Software.
-@REM
-@REM THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-@REM IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-@REM FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-@REM AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-@REM LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-@REM OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-@REM THE SOFTWARE.
+@REM    http://www.apache.org/licenses/LICENSE-2.0
 @REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
 
 @REM ----------------------------------------------------------------------------
 @REM Maven Start Up Batch script

parameter-object/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2021 Ilkka Seppälä
+    Copyright © 2014-2019 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal

parameter-object/src/main/java/com/iluwatar/parameter/object/App.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

parameter-object/src/main/java/com/iluwatar/parameter/object/ParameterObject.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

parameter-object/src/main/java/com/iluwatar/parameter/object/SortOrder.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

parameter-object/src/test/java/com/iluwatar/parameter/object/AppTest.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

parameter-object/src/test/java/com/iluwatar/parameter/object/ParameterObjectTest.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

parameter-object/src/test/java/com/iluwatar/parameter/object/SearchServiceTest.java

@@ -1,6 +1,6 @@
 /*
  * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal

partial-response/pom.xml

@@ -35,6 +35,12 @@
 
     <artifactId>partial-response</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>org.junit.vintage</groupId>
+            <artifactId>junit-vintage-engine</artifactId>
+            <version>5.4.0</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-junit-jupiter</artifactId>

partial-response/src/test/java/com/iluwatar/partialresponse/VideoResourceTest.java

@@ -23,18 +23,17 @@
 
 package com.iluwatar.partialresponse;
 
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.eq;
-
-import java.util.Map;
 import org.junit.jupiter.api.Assertions;
-import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Matchers;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.junit.jupiter.MockitoExtension;
 
+import java.util.Map;
+
 /**
  * tests {@link VideoResource}.
  */
@@ -45,8 +44,8 @@ class VideoResourceTest {
 
   private static VideoResource resource;
 
-  @BeforeEach
-  void setUp() {
+  @BeforeAll
+  static void setUp() {
     var videos = Map.of(
         1, new Video(1, "Avatar", 178, "epic science fiction film",
             "James Cameron", "English"),
@@ -71,7 +70,7 @@ class VideoResourceTest {
     var fields = new String[]{"id", "title", "length"};
 
     var expectedDetails = "{\"id\": 1,\"title\": \"Avatar\",\"length\": 178}";
-    Mockito.when(fieldJsonMapper.toJson(any(Video.class), eq(fields))).thenReturn(expectedDetails);
+    Mockito.when(fieldJsonMapper.toJson(Matchers.any(Video.class), Matchers.eq(fields))).thenReturn(expectedDetails);
 
     var actualFieldsDetails = resource.getDetails(2, fields);
 

pom.xml

@@ -41,8 +41,8 @@
         <spring-data.version>2.0.14.RELEASE</spring-data.version>
         <h2.version>1.4.190</h2.version>
         <junit.version>4.12</junit.version>
-        <junit-jupiter.version>5.7.1</junit-jupiter.version>
-        <junit-vintage.version>${junit-jupiter.version}</junit-vintage.version>
+        <junit-jupiter.version>5.5.2</junit-jupiter.version>
+        <junit-vintage.version>${junit.version}.2</junit-vintage.version>
         <sping-test-junit5.version>1.0.2</sping-test-junit5.version>
         <compiler.version>3.8.1</compiler.version>
         <jacoco.version>0.8.6</jacoco.version>
@@ -274,6 +274,12 @@
                 <artifactId>camel-stream</artifactId>
                 <version>${camel.version}</version>
             </dependency>
+            <dependency>
+                <groupId>junit</groupId>
+                <artifactId>junit</artifactId>
+                <version>${junit.version}</version>
+                <scope>test</scope>
+            </dependency>
             <dependency>
                 <groupId>org.junit.jupiter</groupId>
                 <artifactId>junit-jupiter-api</artifactId>

producer-consumer/src/main/java/com/iluwatar/producer/consumer/Producer.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.producer.consumer;
 
-import java.security.SecureRandom;
+import java.util.Random;
 
 /**
  * Class responsible for producing unit of work that can be expressed as {@link Item} and submitted
@@ -31,7 +31,7 @@ import java.security.SecureRandom;
  */
 public class Producer {
 
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
 
   private final ItemQueue queue;
 

registry/pom.xml

@@ -41,6 +41,10 @@
       <artifactId>junit-jupiter-engine</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+    </dependency>
   </dependencies>
 
   <build>

role-object/pom.xml

@@ -34,6 +34,11 @@
 
   <artifactId>role-object</artifactId>
   <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>

role-object/src/test/java/com/iluwatar/roleobject/ApplicationRoleObjectTest.java

@@ -23,14 +23,14 @@
 
 package com.iluwatar.roleobject;
 
+import org.junit.Test;
+
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
-import org.junit.jupiter.api.Test;
-
-class ApplicationRoleObjectTest {
+public class ApplicationRoleObjectTest {
 
   @Test
-  void shouldExecuteApplicationWithoutException() {
+  public void shouldExecuteApplicationWithoutException() {
     assertDoesNotThrow(() -> ApplicationRoleObject.main(new String[]{}));
   }
 }

role-object/src/test/java/com/iluwatar/roleobject/BorrowerRoleTest.java

@@ -23,16 +23,15 @@
 
 package com.iluwatar.roleobject;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.Assert;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
-
-class BorrowerRoleTest {
+public class BorrowerRoleTest {
 
   @Test
-  void borrowTest() {
+  public void borrowTest() {
     var borrowerRole = new BorrowerRole();
     borrowerRole.setName("test");
-    assertEquals("Borrower test wants to get some money.", borrowerRole.borrow());
+    Assert.assertEquals(borrowerRole.borrow(), "Borrower test wants to get some money.");
   }
 }

role-object/src/test/java/com/iluwatar/roleobject/CustomerCoreTest.java

@@ -23,22 +23,22 @@
 
 package com.iluwatar.roleobject;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
-class CustomerCoreTest {
+public class CustomerCoreTest {
 
   @Test
-  void addRole() {
+  public void addRole() {
     var core = new CustomerCore();
     assertTrue(core.addRole(Role.Borrower));
   }
 
   @Test
-  void hasRole() {
+  public void hasRole() {
     var core = new CustomerCore();
     core.addRole(Role.Borrower);
     assertTrue(core.hasRole(Role.Borrower));
@@ -46,7 +46,7 @@ class CustomerCoreTest {
   }
 
   @Test
-  void remRole() {
+  public void remRole() {
     var core = new CustomerCore();
     core.addRole(Role.Borrower);
 
@@ -60,7 +60,7 @@ class CustomerCoreTest {
   }
 
   @Test
-  void getRole() {
+  public void getRole() {
     var core = new CustomerCore();
     core.addRole(Role.Borrower);
 
@@ -76,17 +76,17 @@ class CustomerCoreTest {
 
 
   @Test
-  void toStringTest() {
+  public void toStringTest() {
     var core = new CustomerCore();
     core.addRole(Role.Borrower);
-    assertEquals("Customer{roles=[Borrower]}", core.toString());
+    assertEquals(core.toString(), "Customer{roles=[Borrower]}");
 
     core = new CustomerCore();
     core.addRole(Role.Investor);
-    assertEquals("Customer{roles=[Investor]}", core.toString());
+    assertEquals(core.toString(), "Customer{roles=[Investor]}");
 
     core = new CustomerCore();
-    assertEquals("Customer{roles=[]}", core.toString());
+    assertEquals(core.toString(), "Customer{roles=[]}");
 
 
   }

role-object/src/test/java/com/iluwatar/roleobject/InvestorRoleTest.java

@@ -23,17 +23,16 @@
 
 package com.iluwatar.roleobject;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.Assert;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
-
-class InvestorRoleTest {
+public class InvestorRoleTest {
 
   @Test
-  void investTest() {
+  public void investTest() {
     var investorRole = new InvestorRole();
     investorRole.setName("test");
     investorRole.setAmountToInvest(10);
-    assertEquals("Investor test has invested 10 dollars", investorRole.invest());
+    Assert.assertEquals(investorRole.invest(), "Investor test has invested 10 dollars");
   }
 }

role-object/src/test/java/com/iluwatar/roleobject/RoleTest.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.roleobject;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import org.junit.Assert;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
-
-class RoleTest {
+public class RoleTest {
 
   @Test
-  void instanceTest() {
+  public void instanceTest() {
     var instance = Role.Borrower.instance();
-    assertTrue(instance.isPresent());
-    assertEquals(instance.get().getClass(), BorrowerRole.class);
+    Assert.assertTrue(instance.isPresent());
+    Assert.assertEquals(instance.get().getClass(), BorrowerRole.class);
   }
 }

saga/pom.xml

@@ -35,6 +35,11 @@
 
     <artifactId>saga</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

saga/src/test/java/com/iluwatar/saga/choreography/SagaApplicationTest.java

@@ -23,19 +23,18 @@
 
 package com.iluwatar.saga.choreography;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
-
 import com.iluwatar.saga.orchestration.SagaApplication;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 
 /***
  * empty test
  */
-class SagaApplicationTest {
-
+public class SagaApplicationTest {
   @Test
-  void shouldExecuteWithoutException() {
+  public void shouldExecuteWithoutException() {
     assertDoesNotThrow(() -> SagaApplication.main(new String[]{}));
   }
-}
+}

saga/src/test/java/com/iluwatar/saga/choreography/SagaChoreographyTest.java

@@ -23,25 +23,24 @@
 
 package com.iluwatar.saga.choreography;
 
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * test to check choreography saga
  */
-class SagaChoreographyTest {
+public class SagaChoreographyTest {
 
 
   @Test
-  void executeTest() {
+  public void executeTest() {
     var sd = serviceDiscovery();
     var service = sd.findAny();
     var badOrderSaga = service.execute(newSaga("bad_order"));
     var goodOrderSaga = service.execute(newSaga("good_order"));
 
-    assertEquals(Saga.SagaResult.ROLLBACKED, badOrderSaga.getResult());
-    assertEquals(Saga.SagaResult.FINISHED, goodOrderSaga.getResult());
+    Assert.assertEquals(badOrderSaga.getResult(), Saga.SagaResult.ROLLBACKED);
+    Assert.assertEquals(goodOrderSaga.getResult(), Saga.SagaResult.FINISHED);
   }
 
   private static Saga newSaga(Object value) {

saga/src/test/java/com/iluwatar/saga/orchestration/SagaApplicationTest.java

@@ -23,15 +23,15 @@
 
 package com.iluwatar.saga.orchestration;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * empty test
  */
-class SagaApplicationTest {
+public class SagaApplicationTest {
 
   @Test
-  void mainTest() {
+  public void mainTest() {
     SagaApplication.main(new String[]{});
   }
-}
+}

saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorInternallyTest.java

@@ -23,30 +23,28 @@
 
 package com.iluwatar.saga.orchestration;
 
-import org.junit.jupiter.api.Test;
-
 import static com.iluwatar.saga.orchestration.Saga.Result;
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import java.util.ArrayList;
 import java.util.List;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * test to test orchestration logic
  */
-class SagaOrchestratorInternallyTest {
+public class SagaOrchestratorInternallyTest {
 
   private final List<String> records = new ArrayList<>();
 
   @Test
-  void executeTest() {
+  public void executeTest() {
     var sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
     var result = sagaOrchestrator.execute(1);
-    assertEquals(Result.ROLLBACK, result);
-    assertArrayEquals(
-            new String[]{"+1", "+2", "+3", "+4", "-4", "-3", "-2", "-1"},
-            records.toArray(new String[]{}));
+    Assert.assertEquals(result, Result.ROLLBACK);
+    Assert.assertArrayEquals(
+        records.toArray(new String[]{}),
+        new String[]{"+1", "+2", "+3", "+4", "-4", "-3", "-2", "-1"});
   }
 
   private static Saga newSaga() {

saga/src/test/java/com/iluwatar/saga/orchestration/SagaOrchestratorTest.java

@@ -23,23 +23,22 @@
 
 package com.iluwatar.saga.orchestration;
 
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * test to check general logic
  */
-class SagaOrchestratorTest {
+public class SagaOrchestratorTest {
 
   @Test
-  void execute() {
+  public void execute() {
     SagaOrchestrator sagaOrchestrator = new SagaOrchestrator(newSaga(), serviceDiscovery());
     Saga.Result badOrder = sagaOrchestrator.execute("bad_order");
     Saga.Result crashedOrder = sagaOrchestrator.execute("crashed_order");
 
-    assertEquals(Saga.Result.ROLLBACK, badOrder);
-    assertEquals(Saga.Result.CRASHED, crashedOrder);
+    Assert.assertEquals(badOrder, Saga.Result.ROLLBACK);
+    Assert.assertEquals(crashedOrder, Saga.Result.CRASHED);
   }
 
   private static Saga newSaga() {

serverless/src/test/java/com/iluwatar/serverless/faas/api/LambdaInfoApiHandlerTest.java

@@ -30,14 +30,17 @@ import static org.mockito.Mockito.when;
 
 import com.amazonaws.services.lambda.runtime.Context;
 import org.junit.jupiter.api.Test;
+import org.junit.runner.RunWith;
+import org.mockito.runners.MockitoJUnitRunner;
 
 /**
  * Unit tests for LambdaInfoApiHandler
  */
-class LambdaInfoApiHandlerTest {
+@RunWith(MockitoJUnitRunner.class)
+public class LambdaInfoApiHandlerTest {
 
   @Test
-  void handleRequestWithMockContext() {
+  public void handleRequestWithMockContext() {
     var lambdaInfoApiHandler = new LambdaInfoApiHandler();
     var context = mock(Context.class);
     when(context.getAwsRequestId()).thenReturn("mock aws request id");

sharding/pom.xml

@@ -36,6 +36,10 @@
     <artifactId>sharding</artifactId>
 
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

sharding/src/main/java/com/iluwatar/sharding/LookupShardManager.java

@@ -23,9 +23,9 @@
 
 package com.iluwatar.sharding;
 
-import java.security.SecureRandom;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Random;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -58,7 +58,7 @@ public class LookupShardManager extends ShardManager {
       return lookupMap.get(key);
     } else {
       var shardCount = shardMap.size();
-      return new SecureRandom().nextInt(shardCount - 1) + 1;
+      return new Random().nextInt(shardCount - 1) + 1;
     }
   }
 

sharding/src/test/java/com/iluwatar/sharding/AppTest.java

@@ -23,17 +23,17 @@
 
 package com.iluwatar.sharding;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
  * Unit tests for App class.
  */
-class AppTest {
+public class AppTest {
 
   @Test
-  void shouldExecuteWithoutException() {
+  public void shouldExecuteWithoutException() {
     assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 

sharding/src/test/java/com/iluwatar/sharding/HashShardManagerTest.java

@@ -23,22 +23,22 @@
 
 package com.iluwatar.sharding;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
 /**
  * Unit tests for HashShardManager class.
  */
-class HashShardManagerTest {
+public class HashShardManagerTest {
 
   private HashShardManager hashShardManager;
 
   /**
    * Initialize hashShardManager instance.
    */
-  @BeforeEach
+  @Before
   public void setup() {
     hashShardManager = new HashShardManager();
     var shard1 = new Shard(1);
@@ -49,11 +49,16 @@ class HashShardManagerTest {
     hashShardManager.addNewShard(shard3);
   }
 
+  @After
+  public void tearDown() {
+
+  }
+
   @Test
-  void testStoreData() {
+  public void testStoreData() {
     var data = new Data(1, "test", Data.DataType.TYPE_1);
     hashShardManager.storeData(data);
-    assertEquals(data, hashShardManager.getShardById(1).getDataById(1));
+    Assert.assertEquals(data, hashShardManager.getShardById(1).getDataById(1));
   }
 
 }

sharding/src/test/java/com/iluwatar/sharding/LookupShardManagerTest.java

@@ -23,24 +23,22 @@
 
 package com.iluwatar.sharding;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
-
 import java.util.Map;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
 /**
  * Unit tests for LookupShardManager class.
  */
-class LookupShardManagerTest {
+public class LookupShardManagerTest {
 
   private LookupShardManager lookupShardManager;
 
   /**
    * Initialize lookupShardManager instance.
    */
-  @BeforeEach
+  @Before
   public void setup() {
     lookupShardManager = new LookupShardManager();
     var shard1 = new Shard(1);
@@ -52,7 +50,7 @@ class LookupShardManagerTest {
   }
 
   @Test
-  void testStoreData() {
+  public void testStoreData() {
     try {
       var data = new Data(1, "test", Data.DataType.TYPE_1);
       lookupShardManager.storeData(data);
@@ -61,9 +59,9 @@ class LookupShardManagerTest {
       var lookupMap = (Map<Integer, Integer>) field.get(lookupShardManager);
       var shardId = lookupMap.get(1);
       var shard = lookupShardManager.getShardById(shardId);
-      assertEquals(data, shard.getDataById(1));
+      Assert.assertEquals(data, shard.getDataById(1));
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 }

sharding/src/test/java/com/iluwatar/sharding/RangeShardManagerTest.java

@@ -23,22 +23,21 @@
 
 package com.iluwatar.sharding;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
 /**
  * Unit tests for RangeShardManager class.
  */
-class RangeShardManagerTest {
+public class RangeShardManagerTest {
 
   private RangeShardManager rangeShardManager;
 
   /**
    * Initialize rangeShardManager instance.
    */
-  @BeforeEach
+  @Before
   public void setup() {
     rangeShardManager = new RangeShardManager();
     var shard1 = new Shard(1);
@@ -50,10 +49,10 @@ class RangeShardManagerTest {
   }
 
   @Test
-  void testStoreData() {
+  public void testStoreData() {
     var data = new Data(1, "test", Data.DataType.TYPE_1);
     rangeShardManager.storeData(data);
-    assertEquals(data, rangeShardManager.getShardById(1).getDataById(1));
+    Assert.assertEquals(data, rangeShardManager.getShardById(1).getDataById(1));
   }
 
 }

sharding/src/test/java/com/iluwatar/sharding/ShardManagerTest.java

@@ -23,46 +23,49 @@
 
 package com.iluwatar.sharding;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
-
 import java.util.Map;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
 /**
  * Unit tests for ShardManager class.
  */
-class ShardManagerTest {
+public class ShardManagerTest {
 
   private ShardManager shardManager;
 
   /**
    * Initialize shardManager instance.
    */
-  @BeforeEach
-  void setup() {
+  @Before
+  public void setup() {
     shardManager = new TestShardManager();
   }
 
+  @After
+  public void tearDown() {
+
+  }
+
   @Test
-  void testAddNewShard() {
+  public void testAddNewShard() {
     try {
       var shard = new Shard(1);
       shardManager.addNewShard(shard);
       var field = ShardManager.class.getDeclaredField("shardMap");
       field.setAccessible(true);
       var map = (Map<Integer, Shard>) field.get(shardManager);
-      assertEquals(1, map.size());
-      assertEquals(shard, map.get(1));
+      Assert.assertEquals(1, map.size());
+      Assert.assertEquals(shard, map.get(1));
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 
   @Test
-  void testRemoveShardById() {
+  public void testRemoveShardById() {
     try {
       var shard = new Shard(1);
       shardManager.addNewShard(shard);
@@ -70,19 +73,19 @@ class ShardManagerTest {
       var field = ShardManager.class.getDeclaredField("shardMap");
       field.setAccessible(true);
       var map = (Map<Integer, Shard>) field.get(shardManager);
-      assertTrue(flag);
-      assertEquals(0, map.size());
+      Assert.assertEquals(true, flag);
+      Assert.assertEquals(0, map.size());
     } catch (IllegalAccessException | NoSuchFieldException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 
   @Test
-  void testGetShardById() {
+  public void testGetShardById() {
     var shard = new Shard(1);
     shardManager.addNewShard(shard);
     var tmpShard = shardManager.getShardById(1);
-    assertEquals(shard, tmpShard);
+    Assert.assertEquals(shard, tmpShard);
   }
 
   class TestShardManager extends ShardManager {

sharding/src/test/java/com/iluwatar/sharding/ShardTest.java

@@ -23,47 +23,50 @@
 
 package com.iluwatar.sharding;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
-
 import java.util.HashMap;
 import java.util.Map;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
 
 /**
  * Unit tests for Shard class.
  */
-class ShardTest {
+public class ShardTest {
 
   private Data data;
 
   private Shard shard;
 
-  @BeforeEach
+  @Before
   public void setup() {
     data = new Data(1, "test", Data.DataType.TYPE_1);
     shard = new Shard(1);
   }
 
+  @After
+  public void tearDown() {
+  }
+
   @Test
-  void testStoreData() {
+  public void testStoreData() {
     try {
       shard.storeData(data);
       var field = Shard.class.getDeclaredField("dataStore");
       field.setAccessible(true);
       var dataMap = (Map<Integer, Data>) field.get(shard);
-      assertEquals(1, dataMap.size());
-      assertEquals(data, dataMap.get(1));
+      Assert.assertEquals(1, dataMap.size());
+      Assert.assertEquals(data, dataMap.get(1));
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
 
   }
 
   @Test
-  void testClearData() {
+  public void testClearData() {
     try {
       var dataMap = new HashMap<Integer, Data>();
       dataMap.put(1, data);
@@ -72,9 +75,9 @@ class ShardTest {
       field.set(shard, dataMap);
       shard.clearData();
       dataMap = (HashMap<Integer, Data>) field.get(shard);
-      assertEquals(0, dataMap.size());
+      Assert.assertEquals(0, dataMap.size());
     } catch (NoSuchFieldException | IllegalAccessException e) {
-      fail("Fail to modify field access.");
+      Assert.fail("Fail to modify field access.");
     }
   }
 }

singleton/pom.xml

@@ -38,6 +38,10 @@
       <artifactId>junit-jupiter-engine</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+    </dependency>
   </dependencies>
   <build>
     <plugins>

singleton/src/test/java/com/iluwatar/singleton/ThreadSafeDoubleCheckLockingTest.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.singleton;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
 import java.lang.reflect.InvocationTargetException;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * Date: 12/29/15 - 19:26 PM.
  *
  * @author Jeroen Meulemeester
  */
-class ThreadSafeDoubleCheckLockingTest extends SingletonTest<ThreadSafeDoubleCheckLocking> {
+public class ThreadSafeDoubleCheckLockingTest extends SingletonTest<ThreadSafeDoubleCheckLocking> {
 
   /**
    * Create a new singleton test instance using the given 'getInstance' method.
@@ -45,12 +43,12 @@ class ThreadSafeDoubleCheckLockingTest extends SingletonTest<ThreadSafeDoubleChe
   /**
    * Test creating new instance by refection.
    */
-  @Test
-  void testCreatingNewInstanceByRefection() throws Exception {
+  @Test(expected = InvocationTargetException.class)
+  public void testCreatingNewInstanceByRefection() throws Exception {
     ThreadSafeDoubleCheckLocking.getInstance();
     var constructor = ThreadSafeDoubleCheckLocking.class.getDeclaredConstructor();
     constructor.setAccessible(true);
-    assertThrows(InvocationTargetException.class, () -> constructor.newInstance((Object[]) null));
+    constructor.newInstance((Object[]) null);
   }
 
 }

spatial-partition/src/main/java/com/iluwatar/spatialpartition/App.java

@@ -23,8 +23,8 @@
 
 package com.iluwatar.spatialpartition;
 
-import java.security.SecureRandom;
 import java.util.HashMap;
+import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -112,7 +112,7 @@ public class App {
   public static void main(String[] args) {
     var bubbles1 = new HashMap<Integer, Bubble>();
     var bubbles2 = new HashMap<Integer, Bubble>();
-    var rand = new SecureRandom();
+    var rand = new Random();
     for (int i = 0; i < 10000; i++) {
       var b = new Bubble(rand.nextInt(300), rand.nextInt(300), i, rand.nextInt(2) + 1);
       bubbles1.put(i, b);

spatial-partition/src/main/java/com/iluwatar/spatialpartition/Bubble.java

@@ -23,9 +23,9 @@
 
 package com.iluwatar.spatialpartition;
 
-import java.security.SecureRandom;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -36,7 +36,7 @@ import org.slf4j.LoggerFactory;
 
 public class Bubble extends Point<Bubble> {
   private static final Logger LOGGER = LoggerFactory.getLogger(Bubble.class);
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
 
   final int radius;
 

subclass-sandbox/pom.xml

@@ -36,6 +36,10 @@
     <artifactId>subclass-sandbox</artifactId>
 
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.github.stefanbirkner</groupId>
             <artifactId>system-lambda</artifactId>

subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/AppTest.java

@@ -23,17 +23,17 @@
 
 package com.iluwatar.subclasssandbox;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
  * App unit tests.
  */
-class AppTest {
+public class AppTest {
 
   @Test
-  void shouldExecuteWithoutException() {
+  public void shouldExecuteWithoutException() {
     assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 }

subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/GroundDiveTest.java

@@ -23,45 +23,45 @@
 
 package com.iluwatar.subclasssandbox;
 
-import static com.github.stefanbirkner.systemlambda.SystemLambda.tapSystemOutNormalized;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import com.github.stefanbirkner.systemlambda.Statement;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
+
+import static com.github.stefanbirkner.systemlambda.SystemLambda.tapSystemOutNormalized;
 
 /**
  * GroundDive unit tests.
  */
-class GroundDiveTest {
+public class GroundDiveTest {
 
   @Test
-  void testMove() throws Exception {
+  public void testMove() throws Exception {
     var groundDive = new GroundDive();
     groundDive.move(1.0, 1.0, 1.0);
     var outputLog = getLogContent(() -> groundDive.move(1.0, 1.0, 1.0));
     var expectedLog = "Move to ( 1.0, 1.0, 1.0 )";
-    assertEquals(outputLog, expectedLog);
+    Assert.assertEquals(outputLog, expectedLog);
   }
 
   @Test
-  void testPlaySound() throws Exception {
+  public void testPlaySound() throws Exception {
     var groundDive = new GroundDive();
     var outputLog = getLogContent(() -> groundDive.playSound("SOUND_NAME", 1));
     var expectedLog = "Play SOUND_NAME with volumn 1";
-    assertEquals(outputLog, expectedLog);
+    Assert.assertEquals(outputLog, expectedLog);
   }
 
   @Test
-  void testSpawnParticles() throws Exception {
+  public void testSpawnParticles() throws Exception {
     var groundDive = new GroundDive();
     final var outputLog = getLogContent(
             () -> groundDive.spawnParticles("PARTICLE_TYPE", 100));
     final var expectedLog = "Spawn 100 particle with type PARTICLE_TYPE";
-    assertEquals(outputLog, expectedLog);
+    Assert.assertEquals(outputLog, expectedLog);
   }
 
   @Test
-  void testActivate() throws Exception {
+  public void testActivate() throws Exception {
     var groundDive = new GroundDive();
     var logs = tapSystemOutNormalized(groundDive::activate)
             .split("\n");
@@ -72,10 +72,10 @@ class GroundDiveTest {
     final var expectedLog2 = "Play GROUNDDIVE_SOUND with volumn 5";
     final var log3 = getLogContent(logs[2]);
     final var expectedLog3 = "Spawn 20 particle with type GROUNDDIVE_PARTICLE";
-    assertEquals(logs.length, expectedSize);
-    assertEquals(log1, expectedLog1);
-    assertEquals(log2, expectedLog2);
-    assertEquals(log3, expectedLog3);
+    Assert.assertEquals(logs.length, expectedSize);
+    Assert.assertEquals(log1, expectedLog1);
+    Assert.assertEquals(log2, expectedLog2);
+    Assert.assertEquals(log3, expectedLog3);
   }
 
   private String getLogContent(Statement statement) throws Exception {

subclass-sandbox/src/test/java/com/iluwatar/subclasssandbox/SkyLaunchTest.java

@@ -23,44 +23,44 @@
 
 package com.iluwatar.subclasssandbox;
 
-import static com.github.stefanbirkner.systemlambda.SystemLambda.tapSystemOutNormalized;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import com.github.stefanbirkner.systemlambda.Statement;
-import org.junit.jupiter.api.Test;
+import org.junit.Assert;
+import org.junit.Test;
+
+import static com.github.stefanbirkner.systemlambda.SystemLambda.tapSystemOutNormalized;
 
 /**
  * SkyLaunch unit tests.
  */
-class SkyLaunchTest {
+public class SkyLaunchTest {
 
   @Test
-  void testMove() throws Exception {
+  public void testMove() throws Exception {
     var skyLaunch = new SkyLaunch();
     var outputLog = getLogContent(() -> skyLaunch.move(1.0, 1.0, 1.0));
     var expectedLog = "Move to ( 1.0, 1.0, 1.0 )";
-    assertEquals(outputLog, expectedLog);
+    Assert.assertEquals(outputLog, expectedLog);
   }
 
   @Test
-  void testPlaySound() throws Exception {
+  public void testPlaySound() throws Exception {
     var skyLaunch = new SkyLaunch();
     var outputLog = getLogContent(() -> skyLaunch.playSound("SOUND_NAME", 1));
     var expectedLog = "Play SOUND_NAME with volumn 1";
-    assertEquals(outputLog, expectedLog);
+    Assert.assertEquals(outputLog, expectedLog);
   }
 
   @Test
-  void testSpawnParticles() throws Exception {
+  public void testSpawnParticles() throws Exception {
     var skyLaunch = new SkyLaunch();
     var outputLog = getLogContent(
             () -> skyLaunch.spawnParticles("PARTICLE_TYPE", 100));
     var expectedLog = "Spawn 100 particle with type PARTICLE_TYPE";
-    assertEquals(outputLog, expectedLog);
+    Assert.assertEquals(outputLog, expectedLog);
   }
 
   @Test
-  void testActivate() throws Exception {
+  public void testActivate() throws Exception {
     var skyLaunch = new SkyLaunch();
     var logs = tapSystemOutNormalized(skyLaunch::activate)
             .split("\n");
@@ -71,10 +71,10 @@ class SkyLaunchTest {
     final var expectedLog2 = "Play SKYLAUNCH_SOUND with volumn 1";
     final var log3 = getLogContent(logs[2]);
     final var expectedLog3 = "Spawn 100 particle with type SKYLAUNCH_PARTICLE";
-    assertEquals(logs.length, expectedSize);
-    assertEquals(log1, expectedLog1);
-    assertEquals(log2, expectedLog2);
-    assertEquals(log3, expectedLog3);
+    Assert.assertEquals(logs.length, expectedSize);
+    Assert.assertEquals(log1, expectedLog1);
+    Assert.assertEquals(log2, expectedLog2);
+    Assert.assertEquals(log3, expectedLog3);
   }
 
   private String getLogContent(Statement statement) throws Exception {

tolerant-reader/pom.xml

@@ -38,6 +38,11 @@
       <artifactId>junit-jupiter-engine</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-migrationsupport</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
   <build>
     <plugins>

tolerant-reader/src/main/java/com/iluwatar/tolerantreader/RainbowFishSerializer.java

@@ -68,7 +68,7 @@ public final class RainbowFishSerializer {
     var map = Map.of(
         "name", rainbowFish.getName(),
         "age", String.format("%d", rainbowFish.getAge()),
-            LENGTH_METERS, String.format("%d", rainbowFish.getLengthMeters()),
+            "lengthMeters", String.format("%d", rainbowFish.getLengthMeters()),
             WEIGHT_TONS, String.format("%d", rainbowFish.getWeightTons()),
         "angry", Boolean.toString(rainbowFish.getAngry()),
         "hungry", Boolean.toString(rainbowFish.getHungry()),
@@ -95,7 +95,7 @@ public final class RainbowFishSerializer {
     return new RainbowFish(
         map.get("name"),
         Integer.parseInt(map.get("age")),
-        Integer.parseInt(map.get(LENGTH_METERS)),
+        Integer.parseInt(map.get("lengthMeters")),
         Integer.parseInt(map.get(WEIGHT_TONS))
     );
   }

tolerant-reader/src/test/java/com/iluwatar/tolerantreader/AppTest.java

@@ -23,13 +23,14 @@
 
 package com.iluwatar.tolerantreader;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
-
 import java.io.File;
+import java.io.IOException;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
 /**
  * Application test
  */

tolerant-reader/src/test/java/com/iluwatar/tolerantreader/RainbowFishSerializerTest.java

@@ -25,32 +25,26 @@ package com.iluwatar.tolerantreader;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotSame;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import java.nio.file.Files;
-import java.nio.file.Path;
-import org.junit.jupiter.api.BeforeEach;
+import java.io.File;
+import org.junit.Rule;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.io.TempDir;
+import org.junit.jupiter.migrationsupport.rules.EnableRuleMigrationSupport;
+import org.junit.rules.TemporaryFolder;
 
 /**
  * Date: 12/30/15 - 18:39 PM
  *
  * @author Jeroen Meulemeester
  */
-
-class RainbowFishSerializerTest {
+@EnableRuleMigrationSupport
+public class RainbowFishSerializerTest {
 
   /**
    * Create a temporary folder, used to generate files in during this test
    */
-  @TempDir
-  static Path testFolder;
-
-  @BeforeEach
-  void beforeEach() {
-    assertTrue(Files.isDirectory(testFolder));
-  }
+  @Rule
+  public final TemporaryFolder testFolder = new TemporaryFolder();
 
   /**
    * Rainbow fish version 1 used during the tests
@@ -66,11 +60,11 @@ class RainbowFishSerializerTest {
    * Verify if a fish, written as version 1 can be read back as version 1
    */
   @Test
-  void testWriteV1ReadV1() throws Exception {
-    final var outputPath = Files.createFile(testFolder.resolve("outputFile"));
-    RainbowFishSerializer.writeV1(V1, outputPath.toString());
+  public void testWriteV1ReadV1() throws Exception {
+    final var outputFile = this.testFolder.newFile();
+    RainbowFishSerializer.writeV1(V1, outputFile.getPath());
 
-    final var fish = RainbowFishSerializer.readV1(outputPath.toString());
+    final var fish = RainbowFishSerializer.readV1(outputFile.getPath());
     assertNotSame(V1, fish);
     assertEquals(V1.getName(), fish.getName());
     assertEquals(V1.getAge(), fish.getAge());
@@ -83,11 +77,11 @@ class RainbowFishSerializerTest {
    * Verify if a fish, written as version 2 can be read back as version 1
    */
   @Test
-  void testWriteV2ReadV1() throws Exception {
-    final var outputPath = Files.createFile(testFolder.resolve("outputFile2"));
-    RainbowFishSerializer.writeV2(V2, outputPath.toString());
+  public void testWriteV2ReadV1() throws Exception {
+    final var outputFile = this.testFolder.newFile();
+    RainbowFishSerializer.writeV2(V2, outputFile.getPath());
 
-    final var fish = RainbowFishSerializer.readV1(outputPath.toString());
+    final var fish = RainbowFishSerializer.readV1(outputFile.getPath());
     assertNotSame(V2, fish);
     assertEquals(V2.getName(), fish.getName());
     assertEquals(V2.getAge(), fish.getAge());
@@ -95,4 +89,4 @@ class RainbowFishSerializerTest {
     assertEquals(V2.getWeightTons(), fish.getWeightTons());
   }
 
-}
+}

tolerant-reader/src/test/java/com/iluwatar/tolerantreader/RainbowFishTest.java

@@ -23,22 +23,22 @@
 
 package com.iluwatar.tolerantreader;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.Assert.assertEquals;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * Date: 12/30/15 - 18:34 PM
  *
  * @author Jeroen Meulemeester
  */
-class RainbowFishTest {
+public class RainbowFishTest {
 
   /**
    * Verify if the getters of a {@link RainbowFish} return the expected values
    */
   @Test
-  void testValues() {
+  public void testValues() {
     final var fish = new RainbowFish("name", 1, 2, 3);
     assertEquals("name", fish.getName());
     assertEquals(1, fish.getAge());

tolerant-reader/src/test/java/com/iluwatar/tolerantreader/RainbowFishV2Test.java

@@ -27,20 +27,20 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * Date: 12/30/15 - 18:35 PM
  *
  * @author Jeroen Meulemeester
  */
-class RainbowFishV2Test {
+public class RainbowFishV2Test {
 
   /**
    * Verify if the getters of a {@link RainbowFish} return the expected values
    */
   @Test
-  void testValues() {
+  public void testValues() {
     final var fish = new RainbowFishV2("name", 1, 2, 3, false, true, false);
     assertEquals("name", fish.getName());
     assertEquals(1, fish.getAge());

tr/singleton/README.md

@@ -1,87 +0,0 @@
----
-layout: pattern
-title: Singleton
-folder: singleton
-permalink: /patterns/singleton/
-categories: Creational
-tags:
-- Gang of Four
----
-
-## Amaç
-
-Bir sınıfın yalnızca bir örneğine sahip olduğundan emin olun ve ona global bir erişim noktası sağlayın.
-
-
-## Açıklama
-
-Örnek
-
-> Büyücülerin büyülerini çalıstıkları tek bir fildişi kule olabilir. Aynı büyülü fildişi kule,
-> büyücüler tarafından her zaman kullanılır. Buradaki fildişi kulesi singleton tasarım desenine örnektir.
-Özetle
-
-> Belirli bir sınıftan yalnızca bir nesnenin oluşturulmasını sağlar.
-Wikipedia açıklaması
-
-
-
-> Yazılım mühendisliğinde, tekil desen, bir sınıfın somutlaştırılmasını tek bir nesneyle sınırlayan
-> bir yazılım tasarım modelidir.Bu,sistemdeki eylemleri koordine etmek için
-> tam olarak bir nesne gerektiğinde kullanışlıdır.
-**Örnek**
-
-Joshua Bloch, Effective Java 2nd Edition p.18
-
-> Enum singleton tasarım desenini uygulamak için en iyi yoldur.
-```java
-public enum EnumIvoryTower {
-  INSTANCE
-}
-```
-
-Tanımladıktan sonra kullanmak için:
-
-```java
-var enumIvoryTower1 = EnumIvoryTower.INSTANCE;
-var enumIvoryTower2 = EnumIvoryTower.INSTANCE;
-assertEquals(enumIvoryTower1, enumIvoryTower2); // true
-```
-
-## Sınıf diagramı
-
-![alt text](https://github.com/iluwatar/java-design-patterns/blob/master/singleton/etc/singleton.urm.png)
-
-## Uygulanabilirlik
-
-Singleton tasarım deseni şu durumlarda kullanılmalıdır
-
-* Bir sınıfın tam olarak bir örneği olmalı ve iyi bilinen bir erişim noktasından istemciler tarafından erişilebilir olmalıdır.
-* Tek örnek alt sınıflandırma yoluyla genişletilebilir olduğunda ve istemciler, kodlarını değiştirmeden genişletilmiş bir örnek kullanabilmelidir
-
-## Use Case
-
-* Logging sınıflarında
-* Database bağlantılarını yönetmek için
-* File manager
-
-## Gerçek dünya örnekleri
-
-* [java.lang.Runtime#getRuntime()](http://docs.oracle.com/javase/8/docs/api/java/lang/Runtime.html#getRuntime%28%29)
-* [java.awt.Desktop#getDesktop()](http://docs.oracle.com/javase/8/docs/api/java/awt/Desktop.html#getDesktop--)
-* [java.lang.System#getSecurityManager()](http://docs.oracle.com/javase/8/docs/api/java/lang/System.html#getSecurityManager--)
-
-
-## Sonuçlar
-
-* Kendi yaratımını ve yaşam döngüsünü kontrol ederek Tek Sorumluluk İlkesini (SRP) ihlal ediyor.
-* Bu nesne tarafından kullanılan bir nesnenin ve kaynakların serbest bırakılmasını önleyen global bir paylaşılan örnek kullanmayı teşvik eder.
-* Birbirine sıkı bağlı kod oluşturur. Singleton tasarım deseni kullanan istemci sınıflarını test etmek zorlaşır.
-* Bir Singleton tasarım deseninden alt sınıflar oluşturmak neredeyse imkansız hale gelir.
-
-## Credits
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59)
-* [Effective Java](https://www.amazon.com/gp/product/0134685997/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0134685997&linkCode=as2&tag=javadesignpat-20&linkId=4e349f4b3ff8c50123f8147c828e53eb)
-* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)
-* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7)

trampoline/src/main/java/com/iluwatar/trampoline/Trampoline.java

@@ -98,7 +98,7 @@ public interface Trampoline<T> {
         return trampoline(this);
       }
 
-      T trampoline(final Trampoline<T> trampoline) {
+      private T trampoline(final Trampoline<T> trampoline) {
         return Stream.iterate(trampoline, Trampoline::jump)
             .filter(Trampoline::complete)
             .findFirst()

typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java

@@ -26,9 +26,9 @@ package com.iluwatar.typeobject;
 import com.iluwatar.typeobject.Candy.Type;
 
 import java.io.IOException;
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Random;
 import org.json.simple.parser.ParseException;
 
 /**
@@ -38,7 +38,7 @@ import org.json.simple.parser.ParseException;
  */
 
 public class CellPool {
-  private static final SecureRandom RANDOM = new SecureRandom();
+  private static final Random RANDOM = new Random();
   public static final String FRUIT = "fruit";
   public static final String CANDY = "candy";
   List<Cell> pool;

unit-of-work/pom.xml

@@ -35,9 +35,19 @@
 
     <artifactId>unit-of-work</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.vintage</groupId>
+            <artifactId>junit-vintage-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.0.0</version>
             <scope>test</scope>
         </dependency>
         <dependency>

unit-of-work/src/test/java/com/iluwatar/unitofwork/AppTest.java

@@ -23,17 +23,17 @@
 
 package com.iluwatar.unitofwork;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import org.junit.Test;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
  * AppTest
  */
-class AppTest {
+public class AppTest {
 
   @Test
-  void shouldExecuteWithoutException() {
+  public void shouldExecuteWithoutException() {
     assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 }

unit-of-work/src/test/java/com/iluwatar/unitofwork/StudentRepositoryTest.java

@@ -23,32 +23,43 @@
 
 package com.iluwatar.unitofwork;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.mockito.Mockito.mock;
+import static org.junit.Assert.assertEquals;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.verifyZeroInteractions;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.junit.jupiter.api.Test;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
 
 /**
  * tests {@link StudentRepository}
  */
-
-class StudentRepositoryTest {
+@RunWith(MockitoJUnitRunner.class)
+public class StudentRepositoryTest {
   private final Student student1 = new Student(1, "Ram", "street 9, cupertino");
   private final Student student2 = new Student(1, "Sham", "Z bridge, pune");
 
-  private final Map<String, List<Student>> context = new HashMap<>();
-  private final StudentDatabase studentDatabase = mock(StudentDatabase.class);
-  private final StudentRepository studentRepository = new StudentRepository(context, studentDatabase);;
+  private Map<String, List<Student>> context;
+  @Mock
+  private StudentDatabase studentDatabase;
+  private StudentRepository studentRepository;
+
+  @Before
+  public void setUp() {
+    context = new HashMap<>();
+    studentRepository = new StudentRepository(context, studentDatabase);
+  }
 
   @Test
-  void shouldSaveNewStudentWithoutWritingToDb() {
+  public void shouldSaveNewStudentWithoutWritingToDb() {
     studentRepository.registerNew(student1);
     studentRepository.registerNew(student2);
 
@@ -57,7 +68,7 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldSaveDeletedStudentWithoutWritingToDb() {
+  public void shouldSaveDeletedStudentWithoutWritingToDb() {
     studentRepository.registerDeleted(student1);
     studentRepository.registerDeleted(student2);
 
@@ -66,7 +77,7 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldSaveModifiedStudentWithoutWritingToDb() {
+  public void shouldSaveModifiedStudentWithoutWritingToDb() {
     studentRepository.registerModified(student1);
     studentRepository.registerModified(student2);
 
@@ -75,7 +86,7 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldSaveAllLocalChangesToDb() {
+  public void shouldSaveAllLocalChangesToDb() {
     context.put(UnitActions.INSERT.getActionValue(), List.of(student1));
     context.put(UnitActions.MODIFY.getActionValue(), List.of(student1));
     context.put(UnitActions.DELETE.getActionValue(), List.of(student1));
@@ -88,7 +99,7 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldNotWriteToDbIfContextIsNull() {
+  public void shouldNotWriteToDbIfContextIsNull() {
     var studentRepository = new StudentRepository(null, studentDatabase);
 
     studentRepository.commit();
@@ -97,16 +108,16 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldNotWriteToDbIfNothingToCommit() {
+  public void shouldNotWriteToDbIfNothingToCommit() {
     var studentRepository = new StudentRepository(new HashMap<>(), studentDatabase);
 
     studentRepository.commit();
 
-    verifyNoMoreInteractions(studentDatabase);
+    verifyZeroInteractions(studentDatabase);
   }
 
   @Test
-  void shouldNotInsertToDbIfNoRegisteredStudentsToBeCommitted() {
+  public void shouldNotInsertToDbIfNoRegisteredStudentsToBeCommitted() {
     context.put(UnitActions.MODIFY.getActionValue(), List.of(student1));
     context.put(UnitActions.DELETE.getActionValue(), List.of(student1));
 
@@ -116,7 +127,7 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldNotModifyToDbIfNotRegisteredStudentsToBeCommitted() {
+  public void shouldNotModifyToDbIfNotRegisteredStudentsToBeCommitted() {
     context.put(UnitActions.INSERT.getActionValue(), List.of(student1));
     context.put(UnitActions.DELETE.getActionValue(), List.of(student1));
 
@@ -126,7 +137,7 @@ class StudentRepositoryTest {
   }
 
   @Test
-  void shouldNotDeleteFromDbIfNotRegisteredStudentsToBeCommitted() {
+  public void shouldNotDeleteFromDbIfNotRegisteredStudentsToBeCommitted() {
     context.put(UnitActions.INSERT.getActionValue(), List.of(student1));
     context.put(UnitActions.MODIFY.getActionValue(), List.of(student1));
 
@@ -134,4 +145,4 @@ class StudentRepositoryTest {
 
     verify(studentDatabase, never()).delete(student1);
   }
-}
+}

update-method/pom.xml

@@ -35,6 +35,10 @@
 
     <artifactId>update-method</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

update-method/src/main/java/com/iluwatar/updatemethod/World.java

@@ -23,9 +23,9 @@
 
 package com.iluwatar.updatemethod;
 
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Random;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -66,7 +66,7 @@ public class World {
    */
   private void processInput() {
     try {
-      int lag = new SecureRandom().nextInt(200) + 50;
+      int lag = new Random().nextInt(200) + 50;
       Thread.sleep(lag);
     } catch (InterruptedException e) {
       LOGGER.error(e.getMessage());

update-method/src/test/java/com/iluwatar/updatemethod/AppTest.java

@@ -23,14 +23,14 @@
 
 package com.iluwatar.updatemethod;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
-class AppTest {
+public class AppTest {
 
   @Test
-  void shouldExecuteApplicationWithoutException() {
+  public void shouldExecuteApplicationWithoutException() {
     assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 }

update-method/src/test/java/com/iluwatar/updatemethod/SkeletonTest.java

@@ -23,60 +23,56 @@
 
 package com.iluwatar.updatemethod;
 
-import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Test;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+public class SkeletonTest {
 
+  private Skeleton skeleton;
 
-class SkeletonTest {
-
-  private static Skeleton skeleton;
-
-  @BeforeAll
-  public static void setup() {
+  @Before
+  public void setup() {
     skeleton = new Skeleton(1);
   }
 
-  @AfterAll
-  public static void tearDown() {
+  @After
+  public void tearDown() {
     skeleton = null;
   }
 
   @Test
-  void testUpdateForPatrollingLeft() {
+  public void testUpdateForPatrollingLeft() {
     skeleton.patrollingLeft = true;
     skeleton.setPosition(50);
     skeleton.update();
-    assertEquals(49, skeleton.getPosition());
+    Assert.assertEquals(49, skeleton.getPosition());
   }
 
   @Test
-  void testUpdateForPatrollingRight() {
+  public void testUpdateForPatrollingRight() {
     skeleton.patrollingLeft = false;
     skeleton.setPosition(50);
     skeleton.update();
-    assertEquals(51, skeleton.getPosition());
+    Assert.assertEquals(51, skeleton.getPosition());
   }
 
   @Test
-  void testUpdateForReverseDirectionFromLeftToRight() {
+  public void testUpdateForReverseDirectionFromLeftToRight() {
     skeleton.patrollingLeft = true;
     skeleton.setPosition(1);
     skeleton.update();
-    assertEquals(0, skeleton.getPosition());
-    assertFalse(skeleton.patrollingLeft);
+    Assert.assertEquals(0, skeleton.getPosition());
+    Assert.assertEquals(false, skeleton.patrollingLeft);
   }
 
   @Test
-  void testUpdateForReverseDirectionFromRightToLeft() {
+  public void testUpdateForReverseDirectionFromRightToLeft() {
     skeleton.patrollingLeft = false;
     skeleton.setPosition(99);
     skeleton.update();
-    assertEquals(100, skeleton.getPosition());
-    assertTrue(skeleton.patrollingLeft);
+    Assert.assertEquals(100, skeleton.getPosition());
+    Assert.assertEquals(true, skeleton.patrollingLeft);
   }
 }

update-method/src/test/java/com/iluwatar/updatemethod/StatueTest.java

@@ -23,37 +23,36 @@
 
 package com.iluwatar.updatemethod;
 
-import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Test;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+public class StatueTest {
 
-class StatueTest {
+  private Statue statue;
 
-  private static Statue statue;
-
-  @BeforeAll
-  public static void setup() {
+  @Before
+  public void setup() {
     statue = new Statue(1, 20);
   }
 
-  @AfterAll
-  public static void tearDown() {
+  @After
+  public void tearDown() {
     statue = null;
   }
 
   @Test
-  void testUpdateForPendingShoot() {
+  public void testUpdateForPendingShoot() {
     statue.frames = 10;
     statue.update();
-    assertEquals(11, statue.frames);
+    Assert.assertEquals(11, statue.frames);
   }
 
   @Test
-  void testUpdateForShooting() {
+  public void testUpdateForShooting() {
     statue.frames = 19;
     statue.update();
-    assertEquals(0, statue.frames);
+    Assert.assertEquals(0, statue.frames);
   }
 }

update-method/src/test/java/com/iluwatar/updatemethod/WorldTest.java

@@ -23,44 +23,41 @@
 
 package com.iluwatar.updatemethod;
 
-import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Test;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+public class WorldTest {
 
-class WorldTest {
+  private World world;
 
-  private static World world;
-
-  @BeforeAll
-  public static void setup() {
+  @Before
+  public void setup() {
     world = new World();
   }
 
-  @AfterAll
-  public static void tearDown() {
+  @After
+  public void tearDown() {
     world = null;
   }
 
   @Test
-  void testRun() {
+  public void testRun() {
     world.run();
-    assertTrue(world.isRunning);
+    Assert.assertEquals(true, world.isRunning);
   }
 
   @Test
-  void testStop() {
+  public void testStop() {
     world.stop();
-    assertFalse(world.isRunning);
+    Assert.assertEquals(false, world.isRunning);
   }
 
   @Test
-  void testAddEntity() {
+  public void testAddEntity() {
     var entity = new Skeleton(1);
     world.addEntity(entity);
-    assertEquals(entity, world.entities.get(0));
+    Assert.assertEquals(entity, world.entities.get(0));
   }
 }