/*
* Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package test.output;
import java.lang.ref.*;
/**
* This class implements a simple test for weak references and reference queues.
*/
public class WeakReferenceTest02 {
public static void main(String[] args) {
// now test with a reference queue
final ReferenceQueue<String> queue = new ReferenceQueue<String>();
final WeakReference<String> w3 = new WeakReference<String>(new String("alive"), queue);
test(w3);
while (true) {
final Object obj = queue.poll();
if (obj == w3) {
System.out.println("true");
break;
}
if (obj == null) {
try {
// Give the reference subsystem time to enqueue 'w3' onto 'queue'
Thread.sleep(10);
} catch (InterruptedException e) {
}
}
}
}
private static void test(final WeakReference<? extends Object> w1) {
System.out.println("" + w1.get());
System.gc();
System.out.println("" + w1.get());
}
}