luni/src/test/java/tests/api/java/util/ConcurrentModificationExceptionTest.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package tests.api.java.util;

import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.LinkedList;

public class ConcurrentModificationExceptionTest extends
        junit.framework.TestCase {

    static public class CollectionModifier implements Runnable {
        Collection col;

        boolean keepGoing = true;

        public CollectionModifier(Collection c) {
            col = c;
        }

        public void stopNow() {
            keepGoing = false;
        }

        public void run() {
            Object someItem = new Integer(-1);
            while (keepGoing) {
                col.add(someItem);
                col.remove(someItem);
            }
        }
    }

    /**
     * java.util.ConcurrentModificationException#ConcurrentModificationException()
     */
    public void test_Constructor() {
        // Test for method java.util.ConcurrentModificationException()
        Collection myCollection = new LinkedList();
        Iterator myIterator = myCollection.iterator();
        for (int counter = 0; counter < 50; counter++)
            myCollection.add(new Integer(counter));
        CollectionModifier cm = new CollectionModifier(myCollection);
        Thread collectionSlapper = new Thread(cm);
        try {
            collectionSlapper.start();
            while (myIterator.hasNext())
                myIterator.next();
        } catch (ConcurrentModificationException e) {
            cm.stopNow();
            return;
        }
        cm.stopNow();
        // The exception should have been thrown--if the code flow makes it here
        // the test has failed
        fail("Failed to throw expected ConcurrentModificationException");
    }

    /**
     * java.util.ConcurrentModificationException#ConcurrentModificationException(java.lang.String)
     */
    public void test_ConstructorLjava_lang_String() {
        // Test for method
        // java.util.ConcurrentModificationException(java.lang.String)
        String errorMessage = "This is an error message";
        try {
            // This is here to stop "unreachable code" unresolved problem
            if (true)
                throw new ConcurrentModificationException(errorMessage);
        } catch (ConcurrentModificationException e) {
            assertTrue("Exception thrown without error message", e.getMessage()
                    .equals(errorMessage));
            return;
        }
        fail("Failed to throw expected ConcurrentModificationException");
    }

    /**
     * Sets up the fixture, for example, open a network connection. This method
     * is called before a test is executed.
     */
    protected void setUp() {
    }

    /**
     * Tears down the fixture, for example, close a network connection. This
     * method is called after a test is executed.
     */
    protected void tearDown() {
    }
}