com.shigengyu.common.ListHashMap.java Source code

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/*******************************************************************************
 * Copyright 2013-2014 Gengyu Shi
 *
 * 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 com.shigengyu.common;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.commons.lang.SystemUtils;

import com.google.common.base.Function;
import com.google.common.collect.ImmutableList;

public class ListHashMap<K, V> implements Iterable<Entry<K, List<V>>> {

    public static <K, V> ListHashMap<K, V> newListHashMap() {
        return new ListHashMap<K, V>();
    }

    private final Map<K, List<V>> map = new ConcurrentHashMap<K, List<V>>();

    public ListHashMap<K, V> addAll(Iterable<V> values, Function<V, K> keySelector) {
        for (V value : values) {
            K key = keySelector.apply(value);
            addItem(key, value);
        }
        return this;
    }

    public ListHashMap<K, V> addItem(K key, V value) {
        if (!map.containsKey(key)) {
            map.put(key, new ArrayList<V>());
        }
        map.get(key).add(value);
        return this;
    }

    public boolean containsItems(String key, V item) {
        return map.containsKey(key) && map.get(key).contains(item);
    }

    public boolean containsKey(String key) {
        return map.containsKey(key);
    }

    public List<V> get(K key) {
        List<V> mutable = getMutable(key);
        if (mutable == null) {
            return null;
        }
        return ImmutableList.copyOf(mutable);
    }

    public List<V> getMutable(K key) {
        return map.get(key);
    }

    @Override
    public Iterator<Entry<K, List<V>>> iterator() {
        return map.entrySet().iterator();
    }

    public List<V> remove(String key) {
        return map.remove(key);
    }

    public boolean removeItem(String key, V value) {
        if (!map.containsKey(key)) {
            return false;
        }
        return map.get(key).remove(value);
    }

    public int size() {
        return map.size();
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        int count = 0;
        for (Entry<K, List<V>> entry : map.entrySet()) {
            sb.append(entry.getKey() + " (" + entry.getKey().hashCode() + ") = " + entry.getValue()
                    + SystemUtils.LINE_SEPARATOR);
            ++count;

            if (count == 10) {
                sb.append("...");
                return sb.toString();
            }
        }
        return sb.toString();
    }
}