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/*
* Copyright (c) 2001, 2005, 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.
*/
/*
* @test
* @bug 4421469 6282555
* @summary Hashtable's toString method should detect self-referential
* hash tables rather than throwing a StackOverflowException.
* @author Josh Bloch, Martin Buchholz
*/
import java.util.HashMap;
import java.util.Hashtable;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class SelfRef {
public static void main(String[] args) {
testMap(new Hashtable<Object,Object>());
testMap(new HashMap<Object,Object>());
testMap(new LinkedHashMap<Object,Object>());
testMap(new ConcurrentHashMap<Object,Object>());
}
private static void testMap(Map<Object,Object> m) {
if (! (m.toString().equals("{}")))
throw new Error();
m.put("Harvey", m);
if (! (m.toString().equals("{Harvey=(this Map)}")))
throw new Error();
m.clear();
m.put(m, "Harvey");
if (! (m.toString().equals("{(this Map)=Harvey}")))
throw new Error();
m.clear();
m.hashCode();
}
}
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