BAEL-1612 (#3811)

* bael-1612

* line

core-java/src/main/java/com/baeldung/finalkeyword/BlackCat.java

@@ -0,0 +1,5 @@
+package com.baeldung.finalkeyword;
+
+public class BlackCat {
+
+}

core-java/src/main/java/com/baeldung/finalkeyword/BlackDog.java

@@ -0,0 +1,6 @@
+package com.baeldung.finalkeyword;
+
+public class BlackDog extends Dog {
+    // public void sound() {
+    // }
+}

core-java/src/main/java/com/baeldung/finalkeyword/Cat.java

@@ -0,0 +1,18 @@
+package com.baeldung.finalkeyword;
+
+public final class Cat {
+
+    private int weight;
+
+    public int getWeight() {
+        return weight;
+    }
+
+    public void setWeight(int weight) {
+        this.weight = weight;
+    }
+
+    public void methodWithFinalArguments(final int x) {
+        // x=1;
+    }
+}

core-java/src/main/java/com/baeldung/finalkeyword/Dog.java

@@ -0,0 +1,7 @@
+package com.baeldung.finalkeyword;
+
+public class Dog {
+    
+    public final void sound() {
+    }
+}

core-java/src/test/java/com/baeldung/finalkeyword/FinalUnitTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.finalkeyword;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class FinalUnitTest {
+
+    @Test
+    public void whenChangedFinalClassProperties_thenChanged() {
+        Cat cat = new Cat();
+        cat.setWeight(1);
+
+        assertEquals(1, cat.getWeight());
+
+    }
+
+    @Test
+    public void whenFinalVariableAssign_thenOnlyOnce() {
+        final int i;
+        i = 1;
+        // i=2;
+    }
+
+    @Test
+    public void whenChangedFinalReference_thenChanged() {
+
+        final Cat cat = new Cat();
+        // cat=new Cat();
+        cat.setWeight(5);
+
+        assertEquals(5, cat.getWeight());
+    }
+}