Added class for lottery numbers and unit tests for it

hexagonal/src/main/java/com/iluwatar/hexagonal/App.java

@@ -23,11 +23,12 @@
 package com.iluwatar.hexagonal;
 
 /**
- * Hello world!
+ * 
+ * Example application demonstrating Hexagonal Architecture
  *
  */
 public class App {
   public static void main(String[] args) {
-    System.out.println("Hello World!");
+    System.out.println("Running hexagonal example");
   }
 }

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

@@ -0,0 +1,152 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014 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.
+ */
+package com.iluwatar.hexagonal.domain;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.PrimitiveIterator;
+import java.util.Random;
+import java.util.Set;
+
+/**
+ *
+ * Value object representing lottery numbers. This lottery uses sets of 4 numbers. The numbers must be unique and
+ * between 1 and 20.
+ *
+ */
+public class LotteryNumbers {
+
+  private final Set<Integer> numbers;
+  
+  public static final int MIN_NUMBER = 1;
+  public static final int MAX_NUMBER = 20;
+  public static final int NUM_NUMBERS = 4;
+
+  /**
+   * Constructor. Creates random lottery numbers.
+   */
+  private LotteryNumbers() {
+    numbers = new HashSet<>();
+    generateRandomNumbers();
+  }
+
+  /**
+   * Constructor. Uses given numbers.
+   */
+  private LotteryNumbers(Set<Integer> givenNumbers) {
+    numbers = new HashSet<>();
+    numbers.addAll(givenNumbers);
+  }
+
+  /**
+   * @return random LotteryNumbers
+   */
+  public static LotteryNumbers createRandom() {
+    return new LotteryNumbers();
+  }
+
+  /**
+   * @return given LotteryNumbers
+   */
+  public static LotteryNumbers create(Set<Integer> givenNumbers) {
+    return new LotteryNumbers(givenNumbers);
+  }
+  
+  /**
+   * @return lottery numbers
+   */
+  public Set<Integer> getNumbers() {
+    return Collections.unmodifiableSet(numbers);
+  }
+  
+  @Override
+  public int hashCode() {
+    final int prime = 31;
+    int result = 1;
+    result = prime * result + ((numbers == null) ? 0 : numbers.hashCode());
+    return result;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if (obj == null) {
+      return false;
+    }
+    if (getClass() != obj.getClass()) {
+      return false;
+    }
+    LotteryNumbers other = (LotteryNumbers) obj;
+    if (numbers == null) {
+      if (other.numbers != null) {
+        return false;
+      }
+    } else if (!numbers.equals(other.numbers)) {
+      return false;
+    }
+    return true;
+  }
+
+  /**
+   * Generates 4 unique random numbers between 1-20 into numbers set.
+   */
+  private void generateRandomNumbers() {
+    numbers.clear();
+    RandomNumberGenerator generator = new RandomNumberGenerator(MIN_NUMBER, MAX_NUMBER);
+    while (numbers.size() < NUM_NUMBERS) {
+      int num = generator.nextInt();
+      if (!numbers.contains(num)) {
+        numbers.add(num);
+      }
+    }
+  }
+
+  /**
+   * 
+   * Helper class for generating random numbers.
+   *
+   */
+  private static class RandomNumberGenerator {
+
+    private PrimitiveIterator.OfInt randomIterator;
+
+    /**
+     * Initialize a new random number generator that generates random numbers in the range [min, max]
+     * 
+     * @param min the min value (inclusive)
+     * @param max the max value (inclusive)
+     */
+    public RandomNumberGenerator(int min, int max) {
+      randomIterator = new Random().ints(min, max + 1).iterator();
+    }
+
+    /**
+     * @return a random number in the range (min, max)
+     */
+    public int nextInt() {
+      return randomIterator.nextInt();
+    }
+  }
+}

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

@@ -22,8 +22,6 @@
  */
 package com.iluwatar.hexagonal;
 
-import static org.junit.Assert.assertTrue;
-
 import org.junit.Test;
 
 /**
@@ -31,11 +29,9 @@ import org.junit.Test;
  */
 public class AppTest {
 
-  /**
-   * Rigourous Test :-)
-   */
   @Test
   public void testApp() {
-    assertTrue(true);
+    String[] args = {};
+    App.main(args);
   }
 }

hexagonal/src/test/java/com/iluwatar/hexagonal/domain/LotteryNumbersTest.java

@@ -0,0 +1,66 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014 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.
+ */
+package com.iluwatar.hexagonal.domain;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.HashSet;
+
+import org.junit.Test;
+
+/**
+ * 
+ * Unit tests for {@link LotteryNumbers}
+ *
+ */
+public class LotteryNumbersTest {
+
+  private static final int NUM_RANDOM_NUMBER_ROUNDS = 1000;
+  
+  @Test
+  public void testGivenNumbers() {
+    LotteryNumbers numbers = LotteryNumbers.create(
+            new HashSet<>(Arrays.asList(1, 2, 3, 4)));
+    assertEquals(numbers.getNumbers().size(), 4);
+    assertTrue(numbers.getNumbers().contains(1));
+    assertTrue(numbers.getNumbers().contains(2));
+    assertTrue(numbers.getNumbers().contains(3));
+    assertTrue(numbers.getNumbers().contains(4));
+  }
+  
+  @Test(expected = UnsupportedOperationException.class)
+  public void testNumbersCantBeModified() {
+    LotteryNumbers numbers = LotteryNumbers.create(
+            new HashSet<>(Arrays.asList(1, 2, 3, 4)));
+    numbers.getNumbers().add(5);
+  }
+  
+  @Test
+  public void testRandomNumbers() {
+    for (int i = 0; i < NUM_RANDOM_NUMBER_ROUNDS; i++) {
+      LotteryNumbers numbers = LotteryNumbers.createRandom();
+    }
+  }
+}