org.apache.jetspeed.util.DefaultKeyValue Maven / Gradle / Ivy
Show all versions of jetspeed-portal Show documentation
/*
* 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 org.apache.jetspeed.util;
import java.util.Map;
/**
* A mutable KeyValue pair.
*
* @version $Id: DefaultKeyValue.java 761757 2009-04-03 18:46:58Z woonsan $
*/
public class DefaultKeyValue implements KeyValue
{
private K key;
private V value;
private boolean compareByKeyOnly;
/**
* Constructs a new pair with the specified key and given value.
*
* @param key
* the key for the entry, may be null
* @param value
* the value for the entry, may be null
*/
public DefaultKeyValue(final K key, final V value)
{
this(key, value, false);
}
/**
* Constructs a new pair with the specified key and given value.
*
* @param key
* the key for the entry, may be null
* @param value
* the value for the entry, may be null
* @param compareByKeyOnly
* flag if equals() depends on key only
*/
public DefaultKeyValue(final K key, final V value, final boolean compareByKeyOnly)
{
this.key = key;
this.value = value;
this.compareByKeyOnly = compareByKeyOnly;
}
/**
* Constructs a new pair from the specified KeyValue.
*
* @param pair
* the pair to copy, must not be null
* @throws NullPointerException
* if the entry is null
*/
public DefaultKeyValue(final KeyValue pair)
{
this(pair, false);
}
/**
* Constructs a new pair from the specified KeyValue.
*
* @param pair
* the pair to copy, must not be null
* @param compareByKeyOnly
* flag if equals() depends on key only
* @throws NullPointerException
* if the entry is null
*/
public DefaultKeyValue(final KeyValue pair, final boolean compareByKeyOnly)
{
this(pair.getKey(), pair.getValue(), compareByKeyOnly);
}
/**
* Constructs a new pair from the specified Map.Entry.
*
* @param entry
* the entry to copy, must not be null
* @throws NullPointerException
* if the entry is null
*/
public DefaultKeyValue(final Map.Entry entry)
{
this(entry, false);
}
/**
* Constructs a new pair from the specified Map.Entry.
*
* @param entry
* the entry to copy, must not be null
* @param compareByKeyOnly
* flag if equals() depends on key only
* @throws NullPointerException
* if the entry is null
*/
public DefaultKeyValue(final Map.Entry entry, final boolean compareByKeyOnly)
{
this(entry.getKey(), entry.getValue(), compareByKeyOnly);
}
/**
* Gets the key from the pair.
*
* @return the key
*/
public K getKey()
{
return key;
}
/**
* Gets the value from the pair.
*
* @return the value
*/
public V getValue()
{
return value;
}
// -----------------------------------------------------------------------
/**
* Sets the key.
*
* @param key
* the new key
* @return the old key
* @throws IllegalArgumentException
* if key is this object
*/
public K setKey(final K key)
{
if (key == this)
{
throw new IllegalArgumentException("DefaultKeyValue may not contain itself as a key.");
}
final K old = this.key;
this.key = key;
return old;
}
/**
* Sets the value.
*
* @return the old value of the value
* @param value
* the new value
* @throws IllegalArgumentException
* if value is this object
*/
public V setValue(final V value)
{
if (value == this)
{
throw new IllegalArgumentException("DefaultKeyValue may not contain itself as a value.");
}
final V old = this.value;
this.value = value;
return old;
}
// -----------------------------------------------------------------------
/**
* Compares this KeyValue with another KeyValue.
* Returns true if the compared object is also a DefaultKeyValue,
* and its key and value are equal to this object's key and value.
*
* @param obj
* the object to compare to
* @return true if equal key and value
*/
@SuppressWarnings("unchecked")
public boolean equals(final Object obj)
{
if (obj == this)
{
return true;
}
if (obj instanceof DefaultKeyValue == false)
{
return false;
}
DefaultKeyValue other = (DefaultKeyValue) obj;
if (this.compareByKeyOnly)
{
return (getKey() == null ? other.getKey() == null : getKey().equals(other.getKey()));
}
else
{
return (getKey() == null ? other.getKey() == null : getKey().equals(other.getKey())) &&
(getValue() == null ? other.getValue() == null : getValue().equals(other.getValue()));
}
}
/**
* Gets a hashCode compatible with the equals method.
*
* @return a suitable hash code
*/
public int hashCode()
{
return (getKey() == null ? 0 : getKey().hashCode()) ^ (getValue() == null ? 0 : getValue().hashCode());
}
}