Java 11 migration: ambassador async-method-invocation balking bridge builder (#1076)

* Moves ambassador pattern to java 11

* Moves async-method-invocation pattern  to java 11

* Moves balking pattern  to java 11

* Moves bridge pattern  to java 11

* Moves builder pattern  to java 11

ambassador/README.md

@@ -42,7 +42,7 @@ A remote services represented as a singleton.
 ```java
 public class RemoteService implements RemoteServiceInterface {
 
-		private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
     private static RemoteService service = null;
 
     static synchronized RemoteService getRemoteService() {
@@ -56,14 +56,14 @@ public class RemoteService implements RemoteServiceInterface {
 
     @Override
     public long doRemoteFunction(int value) {
-
         long waitTime = (long) Math.floor(Math.random() * 1000);
 
         try {
             sleep(waitTime);
         } catch (InterruptedException e) {
-            LOGGER.error("Thread sleep interrupted", e)
+            LOGGER.error("Thread sleep interrupted", e);
         }
+
         return waitTime >= 200 ? value * 10 : -1;
     }
 }
@@ -137,7 +137,7 @@ public class Client {
 
     long useService(int value) {
         long result = serviceAmbassador.doRemoteFunction(value);
-        LOGGER.info("Service result: " + result)
+        LOGGER.info("Service result: " + result);
         return result;
     }
 }
@@ -146,10 +146,14 @@ public class Client {
 And here are two clients using the service.
 
 ```java
-Client host1 = new Client();
-Client host2 = new Client();
-host1.useService(12);
-host2.useService(73);
+public class App {
+  public static void main(String[] args) {
+    Client host1 = new Client();
+    Client host2 = new Client();
+    host1.useService(12);
+    host2.useService(73);
+  }
+}
 ```
 
 ## Applicability

ambassador/src/main/java/com/iluwatar/ambassador/Client.java

@@ -35,7 +35,7 @@ public class Client {
   private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
 
   long useService(int value) {
-    long result = serviceAmbassador.doRemoteFunction(value);
+    var result = serviceAmbassador.doRemoteFunction(value);
     LOGGER.info("Service result: " + result);
     return result;
   }

ambassador/src/main/java/com/iluwatar/ambassador/RemoteService.java

@@ -33,7 +33,7 @@ import org.slf4j.LoggerFactory;
  * A remote legacy application represented by a Singleton implementation.
  */
 public class RemoteService implements RemoteServiceInterface {
-  static final int THRESHOLD = 200;
+  private static final int THRESHOLD = 200;
   private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
   private static RemoteService service = null;
   private final RandomProvider randomProvider;
@@ -50,7 +50,7 @@ public class RemoteService implements RemoteServiceInterface {
   }
 
   /**
-   * This constuctor is used for testing purposes only.
+   * This constructor is used for testing purposes only.
    */
   RemoteService(RandomProvider randomProvider) {
     this.randomProvider = randomProvider;

ambassador/src/main/java/com/iluwatar/ambassador/ServiceAmbassador.java

@@ -48,21 +48,19 @@ public class ServiceAmbassador implements RemoteServiceInterface {
   }
 
   private long checkLatency(int value) {
-    long startTime = System.currentTimeMillis();
-    long result = RemoteService.getRemoteService().doRemoteFunction(value);
-    long timeTaken = System.currentTimeMillis() - startTime;
+    var startTime = System.currentTimeMillis();
+    var result = RemoteService.getRemoteService().doRemoteFunction(value);
+    var timeTaken = System.currentTimeMillis() - startTime;
 
     LOGGER.info("Time taken (ms): " + timeTaken);
     return result;
   }
 
   private long safeCall(int value) {
-
-    int retries = 0;
-    long result = FAILURE;
+    var retries = 0;
+    var result = (long) FAILURE;
 
     for (int i = 0; i < RETRIES; i++) {
-
       if (retries >= RETRIES) {
         return FAILURE;
       }

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

@@ -28,10 +28,10 @@ import org.junit.jupiter.api.Test;
 /**
  * Application test
  */
-public class AppTest {
+class AppTest {
 
   @Test
-  public void test() {
+  void test() {
     App.main(new String[]{});
   }
 }

ambassador/src/test/java/com/iluwatar/ambassador/ClientTest.java

@@ -30,13 +30,12 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 /**
  * Test for {@link Client}
  */
-public class ClientTest {
+class ClientTest {
 
   @Test
-  public void test() {
-
+  void test() {
     Client client = new Client();
-    long result = client.useService(10);
+    var result = client.useService(10);
 
     assertTrue(result == 100 || result == RemoteService.FAILURE);
   }

ambassador/src/test/java/com/iluwatar/ambassador/RemoteServiceTest.java

@@ -23,34 +23,31 @@
 
 package com.iluwatar.ambassador;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.iluwatar.ambassador.util.RandomProvider;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * Test for {@link RemoteService}
  */
-public class RemoteServiceTest {
+class RemoteServiceTest {
 
   @Test
-  public void testFailedCall() {
-    RemoteService remoteService = new RemoteService(
-        new StaticRandomProvider(0.21));
-    long result = remoteService.doRemoteFunction(10);
+  void testFailedCall() {
+    var remoteService = new RemoteService(new StaticRandomProvider(0.21));
+    var result = remoteService.doRemoteFunction(10);
     assertEquals(RemoteServiceInterface.FAILURE, result);
   }
 
   @Test
-  public void testSuccessfulCall() {
-    RemoteService remoteService = new RemoteService(
-        new StaticRandomProvider(0.2));
-    long result = remoteService.doRemoteFunction(10);
+  void testSuccessfulCall() {
+    var remoteService = new RemoteService(new StaticRandomProvider(0.2));
+    var result = remoteService.doRemoteFunction(10);
     assertEquals(100, result);
   }
 
-  private class StaticRandomProvider implements RandomProvider {
+  private static class StaticRandomProvider implements RandomProvider {
     private double value;
 
     StaticRandomProvider(double value) {

ambassador/src/test/java/com/iluwatar/ambassador/ServiceAmbassadorTest.java

@@ -30,10 +30,10 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 /**
  * Test for {@link ServiceAmbassador}
  */
-public class ServiceAmbassadorTest {
+class ServiceAmbassadorTest {
 
   @Test
-  public void test() {
+  void test() {
     long result = new ServiceAmbassador().doRemoteFunction(10);
     assertTrue(result == 100 || result == RemoteServiceInterface.FAILURE);
   }