Merge pull request eugenp#12107 from chrisjaimes/random_enum_value

davidmartinezbarua · web-flow · commit 2d9fea54064b · 2022-04-28T11:30:10.000-03:00
added randomDirection method to Enum. Created RandomEnumGenerator
diff --git a/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/randomenum/Direction.java b/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/randomenum/Direction.java
@@ -0,0 +1,22 @@
+package com.baeldung.enums.randomenum;
+
+import java.util.Random;
+
+/**
+ * Represents directions.
+ */
+public enum Direction {
+    EAST, WEST, SOUTH, NORTH;
+
+    private static final Random PRNG = new Random();
+
+    /**
+     * Generate a random direction.
+     *
+     * @return a random direction
+     */
+    public static Direction randomDirection() {
+        Direction[] directions = values();
+        return directions[PRNG.nextInt(directions.length)];
+    }
+}
diff --git a/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/randomenum/RandomEnumGenerator.java b/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/randomenum/RandomEnumGenerator.java
@@ -0,0 +1,17 @@
+package com.baeldung.enums.randomenum;
+
+import java.util.Random;
+
+public class RandomEnumGenerator<T extends Enum<T>> {
+
+    private static final Random PRNG = new Random();
+    private final T[] values;
+
+    public RandomEnumGenerator(Class<T> e) {
+        values = e.getEnumConstants();
+    }
+
+    public T randomEnum() {
+        return values[PRNG.nextInt(values.length)];
+    }
+}
diff --git a/core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/enums/randomenum/RandomEnumUnitTest.java b/core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/enums/randomenum/RandomEnumUnitTest.java
@@ -0,0 +1,23 @@
+package com.baeldung.enums.randomenum;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RandomEnumUnitTest {
+
+    @Test
+    public void givenEnumType_whenUsingStaticMethod_valueIsRandomlyGenerated() {
+        Direction direction = Direction.randomDirection();
+        assertThat(direction).isNotNull();
+        assertThat(direction instanceof Direction);
+    }
+
+    @Test
+    public void givenEnumType_whenGeneratingRandomValue_valueIsOfClassAndNotNull() {
+        RandomEnumGenerator reg = new RandomEnumGenerator(Direction.class);
+        Object direction = reg.randomEnum();
+        assertThat(direction).isNotNull();
+        assertThat(direction instanceof Direction);
+    }
+}
