| /* ObjectIdentityWrapper.java -- Wrapper class used to override equals() |
| and hashCode() to be as discriminating as possible |
| Copyright (C) 1998 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.io; |
| |
| /** |
| This class is a thin wrapper around <code>Object</code> that makes |
| the methods <code>hashCode()</code> and <code>equals(Object)</code> |
| as discriminating as possible. |
| */ |
| public class ObjectIdentityWrapper |
| { |
| |
| /** |
| Constructs a <code>ObjectIdentityWrapper</code> that is wrapped |
| around o. |
| */ |
| public ObjectIdentityWrapper( Object o ) |
| { |
| object = o; |
| } |
| |
| /** |
| Uses <code>System.identityHashCode(Object)</code> to compute a |
| hash code for the object wrapped by this |
| <code>ObjectIdentityWrapper</code>. |
| |
| @see java.lang.System#identityHashCode(java.lang.Object) |
| @see java.util.Hashtable |
| @see java.lang.Object#hashCode() |
| */ |
| public int hashCode() |
| { |
| return System.identityHashCode( object ); |
| } |
| |
| /** |
| Uses the <code>==</code> operator to test for equality between |
| the object wrapped by this <code>ObjectIdentityWrapper</code> and |
| the object wrapped by the <code>ObjectIdentityWrapper</code> o. |
| Returns false if o is not a <code>ObjectIdentityWrapper</code>. |
| |
| @see java.util.Hashtable |
| @see java.lang.Object#equals() |
| */ |
| public boolean equals( Object o ) |
| { |
| if( o instanceof ObjectIdentityWrapper ) |
| return object == ((ObjectIdentityWrapper)o).object; |
| else |
| return false; |
| } |
| |
| public String toString() |
| { |
| return "ObjectIdentityWrapper< " + object + ", " + hashCode() + " >"; |
| } |
| |
| /** |
| The <code>Object</code> wrapped by this |
| <code>ObjectIdentityWrapper</code>. |
| */ |
| public Object object; |
| } |