001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.collections.keyvalue; 018 019 import org.apache.commons.collections.KeyValue; 020 021 /** 022 * Abstract pair class to assist with creating <code>KeyValue</code> 023 * and {@link java.util.Map.Entry Map.Entry} implementations. 024 * 025 * @since Commons Collections 3.0 026 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 027 * 028 * @author James Strachan 029 * @author Michael A. Smith 030 * @author Neil O'Toole 031 * @author Stephen Colebourne 032 */ 033 public abstract class AbstractKeyValue implements KeyValue { 034 035 /** The key */ 036 protected Object key; 037 /** The value */ 038 protected Object value; 039 040 /** 041 * Constructs a new pair with the specified key and given value. 042 * 043 * @param key the key for the entry, may be null 044 * @param value the value for the entry, may be null 045 */ 046 protected AbstractKeyValue(Object key, Object value) { 047 super(); 048 this.key = key; 049 this.value = value; 050 } 051 052 /** 053 * Gets the key from the pair. 054 * 055 * @return the key 056 */ 057 public Object getKey() { 058 return key; 059 } 060 061 /** 062 * Gets the value from the pair. 063 * 064 * @return the value 065 */ 066 public Object getValue() { 067 return value; 068 } 069 070 /** 071 * Gets a debugging String view of the pair. 072 * 073 * @return a String view of the entry 074 */ 075 public String toString() { 076 return new StringBuffer() 077 .append(getKey()) 078 .append('=') 079 .append(getValue()) 080 .toString(); 081 } 082 083 }