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A collection of classes shared by broadleaf profile, cms, admin, and core.
There is a newer version: 3.1.15-GA
/*
 * #%L
 * BroadleafCommerce Common Libraries
 * %%
 * Copyright (C) 2009 - 2013 Broadleaf Commerce
 * %%
 * 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.
 * #L%
 */
package org.broadleafcommerce.common.util;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.TreeSet;


/**
 * Convenience methods for interacting with maps
 * 
 * @author Andre Azzolini (apazzolini)
 */
public class BLCMapUtils {
    
    /**
     * Given a collection of values and a TypedClosure that maps an appropriate key for a given value,
     * returns a HashMap of the key to the value.
     * 
     * Note: If two values share the same key, the later one will override the previous one in the returned map
     * @see #keyedListMap(Iterable, TypedClosure)
     * 
     * List --> Map
     * 
     * @param values
     * @param closure
     * @return the map
     */
    public static , V> Map keyedMap(CV values, TypedClosure closure) {
        Map map = new HashMap();
        
        for (V value : values) {
            K key = closure.getKey(value);
            map.put(key, value);
        }
        
        return map;
    }
    
    /**
     * Given an array of values and a TypedClosure that maps an appropriate key for a given value,
     * returns a HashMap of the key to the value.
     * 
     * Note: If two values share the same key, the later one will override the previous one in the returned map
     * @see #keyedListMap(Iterable, TypedClosure)
     * 
     * V[] --> Map
     * 
     * @param values
     * @param closure
     * @return the map
     */
    public static  Map keyedMap(V[] values, TypedClosure closure) {
        Map map = new HashMap();
        
        if (values != null) {
            for (V value : values) {
                K key = closure.getKey(value);
                map.put(key, value);
            }
        }
        
        return map;
    }
    
    /**
     * Given a collection of values and a TypedClosure that maps an appropriate key for a given value,
     * returns a HashMap of the key to a list of values that map to that key.
     * 
     * @see #keyedMap(Iterable, TypedClosure)
     * 
     * List --> Map>
     * 
     * @param values
     * @param closure
     * @return the map
     */
    public static , V> Map> keyedListMap(CV values, TypedClosure closure) {
        Map> map = new HashMap>();
        
        for (V value : values) {
            K key = closure.getKey(value);
            List list = map.get(key);
            if (list == null) {
                list = new ArrayList();
                map.put(key, list);
            }
            list.add(value);
        }
        
        return map;
    }
    
    public static  Map valueSortedMap(Map map, Comparator> comparator) {
        Set> valueSortedEntries = new TreeSet>(comparator);
        
        for (Entry entry : map.entrySet()) {
            valueSortedEntries.add(entry);
        }
        
        Map sortedMap = new LinkedHashMap(map.size());
        for (Entry entry : valueSortedEntries) {
            sortedMap.put(entry.getKey(), entry.getValue());
        }
        
        return sortedMap;
    }

}