Mega Code Archive
Map from a given key to a list of values
<![CDATA[
//package org.streets.commons.collections;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
/**
* Map from a given key to a list of values
*
* @author dzb
*/
public class MapList<K, V> extends HashMap<K, List<V>> {
private static final long serialVersionUID = 3462998132471897564L;
public void add(K key, V value) {
List<V> values = get(key);
if (values == null) {
values = new ArrayList<V>();
put(key, values);
}
values.add(value);
}
public void remove(K key, V value) {
List<V> values = get(key);
if (values != null) {
values.remove(value);
}
}
public List<V> list(K key) {
return super.get(key);
}
public V first(K key) {
List<V> list = list(key);
if (list != null && list.size() > 0) {
return list.get(0);
}
return null;
}
}
]]>