collections work

core-java/src/test/java/org/baeldung/java/CoreJavaUnitTest.java

@@ -1,7 +1,45 @@
 package org.baeldung.java;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import org.apache.commons.collections4.ListUtils;
+import org.junit.Test;
+
+import com.google.common.collect.ImmutableList;
+
 public class CoreJavaUnitTest {
 
     // tests -
 
+    @Test
+    public final void givenUsingTheJdk_whenArrayListIsSynchronized_thenCorrect() {
+        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
+        final List<String> synchronizedList = Collections.synchronizedList(list);
+        System.out.println("Synchronized List is: " + synchronizedList);
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingTheJdk_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
+        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = Collections.unmodifiableList(list);
+        unmodifiableList.add("four");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingGuava_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
+        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = ImmutableList.copyOf(list);
+        unmodifiableList.add("four");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingCommonsCollections_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
+        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = ListUtils.unmodifiableList(list);
+        unmodifiableList.add("four");
+    }
+
 }