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 */ 017package org.apache.commons.chain.web; 018 019import java.util.Map; 020import java.util.Objects; 021 022/** 023 * {@code Map.Entry} implementation that can be constructed to either be read-only 024 * or not. 025 * 026 * @version $Revision$ $Date$ 027 * 028 * @param <T> type of the value 029 */ 030public class MapEntry<T> implements Map.Entry<String, T> { 031 032 /** 033 * The entry key. 034 */ 035 private final String key; 036 037 /** 038 * The entry value. 039 */ 040 private T value; 041 042 /** 043 * Whether the entry can be modified. 044 */ 045 private final boolean modifiable; 046 047 /** 048 * Creates a map entry that can either allow modifications or not. 049 * 050 * @param key The entry key 051 * @param value The entry value 052 * @param modifiable Whether the entry should allow modification or not 053 */ 054 public MapEntry(String key, T value, boolean modifiable) { 055 this.key = key; 056 this.value = value; 057 this.modifiable = modifiable; 058 } 059 060 /** 061 * Gets the entry key. 062 * 063 * @return The entry key 064 */ 065 @Override 066 public String getKey() { 067 return key; 068 } 069 070 /** 071 * Gets the entry value. 072 * 073 * @return The entry key 074 */ 075 @Override 076 public T getValue() { 077 return value; 078 } 079 080 /** 081 * Sets the entry value if the entry can be modified. 082 * 083 * @param val The new value 084 * 085 * @return The old entry value 086 * 087 * @throws UnsupportedOperationException If the entry cannot be modified 088 */ 089 @Override 090 public T setValue(T val) { 091 if (modifiable) { 092 T oldVal = this.value; 093 this.value = val; 094 return oldVal; 095 } else { 096 throw new UnsupportedOperationException(); 097 } 098 } 099 100 /** 101 * Determines if this entry is equal to the passed object. 102 * 103 * @param o The object to test 104 * 105 * @return True if equal, else false 106 */ 107 @Override 108 public boolean equals(Object o) { 109 if (this == o) { 110 return true; 111 } 112 if (o == null || getClass() != o.getClass()) { 113 return false; 114 } 115 final MapEntry<?> other = (MapEntry<?>) o; 116 return Objects.equals(key, other.key) && Objects.equals(value, other.value); 117 } 118 119 /** 120 * Returns the hashcode for this entry. 121 * 122 * @return The and'ed hashcode of the key and value 123 */ 124 @Override 125 public int hashCode() { 126 return Objects.hashCode(getKey()) ^ Objects.hashCode(getValue()); 127 } 128}