/*
* Copyright 2002-2010 the original author or authors.
*
* 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.springframework.util;
import java.io.Serializable;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Simple implementation of {@link MultiValueMap} that wraps a {@link LinkedHashMap},
* storing multiple values in a {@link LinkedList}.
*
* <p>This Map implementation is generally not thread-safe. It is primarily designed
* for data structures exposed from request objects, for use in a single thread only.
*
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.0
*/
public class LinkedMultiValueMap<K, V> implements MultiValueMap<K, V>, Serializable {
private static final long serialVersionUID = 3801124242820219131L;
private final Map<K, List<V>> targetMap;
/**
* Create a new LinkedMultiValueMap that wraps a {@link LinkedHashMap}.
*/
public LinkedMultiValueMap() {
this.targetMap = new LinkedHashMap<K, List<V>>();
}
/**
* Create a new LinkedMultiValueMap that wraps a {@link LinkedHashMap}
* with the given initial capacity.
* @param initialCapacity the initial capacity
*/
public LinkedMultiValueMap(int initialCapacity) {
this.targetMap = new LinkedHashMap<K, List<V>>(initialCapacity);
}
/**
* Copy constructor: Create a new LinkedMultiValueMap with the same mappings
* as the specified Map.
* @param otherMap the Map whose mappings are to be placed in this Map
*/
public LinkedMultiValueMap(Map<K, List<V>> otherMap) {
this.targetMap = new LinkedHashMap<K, List<V>>(otherMap);
}
// MultiValueMap implementation
public void add(K key, V value) {
List<V> values = this.targetMap.get(key);
if (values == null) {
values = new LinkedList<V>();
this.targetMap.put(key, values);
}
values.add(value);
}
public V getFirst(K key) {
List<V> values = this.targetMap.get(key);
return (values != null ? values.get(0) : null);
}
public void set(K key, V value) {
List<V> values = new LinkedList<V>();
values.add(value);
this.targetMap.put(key, values);
}
public void setAll(Map<K, V> values) {
for (Entry<K, V> entry : values.entrySet()) {
set(entry.getKey(), entry.getValue());
}
}
public Map<K, V> toSingleValueMap() {
LinkedHashMap<K, V> singleValueMap = new LinkedHashMap<K,V>(this.targetMap.size());
for (Entry<K, List<V>> entry : targetMap.entrySet()) {
singleValueMap.put(entry.getKey(), entry.getValue().get(0));
}
return singleValueMap;
}
// Map implementation
public int size() {
return this.targetMap.size();
}
public boolean isEmpty() {
return this.targetMap.isEmpty();
}
public boolean containsKey(Object key) {
return this.targetMap.containsKey(key);
}
public boolean containsValue(Object value) {
return this.targetMap.containsValue(value);
}
public List<V> get(Object key) {
return this.targetMap.get(key);
}
public List<V> put(K key, List<V> value) {
return this.targetMap.put(key, value);
}
public List<V> remove(Object key) {
return this.targetMap.remove(key);
}
public void putAll(Map<? extends K, ? extends List<V>> m) {
this.targetMap.putAll(m);
}
public void clear() {
this.targetMap.clear();
}
public Set<K> keySet() {
return this.targetMap.keySet();
}
public Collection<List<V>> values() {
return this.targetMap.values();
}
public Set<Entry<K, List<V>>> entrySet() {
return this.targetMap.entrySet();
}
@Override
public boolean equals(Object obj) {
return this.targetMap.equals(obj);
}
@Override
public int hashCode() {
return this.targetMap.hashCode();
}
@Override
public String toString() {
return this.targetMap.toString();
}
}
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