Map from a given key to a set of values : Map « Collections Data Structure « Java






  1. Java
  2. Collections Data Structure
  3. Map

Map from a given key to a set of values

      
//package org.streets.commons.collections;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

/**
 * Map from a given key to a set of values
 * 
 * @author dzb
 */
public class MapSet<K, V> extends HashMap<K, Set<V>> {

  private static final long serialVersionUID = 3462998132471897564L;

  public void add(K key, V value) {
    Set<V> values = get(key);
    if (values == null) {
      values = new HashSet<V>();
      put(key, values);
    }
    values.add(value);
  }

  public void remove(K key, V value) {
    Set<V> values = get(key);
    if (values != null) {
      values.remove(value);
    }
  }
}








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