axis-rt-core/src/main/java/org/apache/axis/utils/IDKey.java

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed 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 org.apache.axis.utils;

/**
 * Wrap an identity key (System.identityHashCode())
 */ 
public class IDKey {
    private Object value = null;
    private int id = 0;

    /**
     * Constructor for IDKey
     * @param _value
     */ 
    public IDKey(Object _value) {
        // This is the Object hashcode 
        id = System.identityHashCode(_value);  
        // There have been some cases (bug 11706) that return the 
        // same identity hash code for different objects.  So 
        // the value is also added to disambiguate these cases.
        value = _value;
    }

    /**
     * returns hashcode
     * @return
     */ 
    public int hashCode() {
       return id;
    }

    /**
     * checks if instances are equal
     * @param other
     * @return
     */ 
    public boolean equals(Object other) {
        if (!(other instanceof IDKey)) {
            return false;
        }
        IDKey idKey = (IDKey) other;
        if (id != idKey.id) {
            return false;
        }
        // Note that identity equals is used.
        return value == idKey.value;
    }
}