IgnoreCaseMap.java

/**
 * Copyright 2016 benjobs
 * <p>
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.opencron.common.utils;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

/**
 * 当Key值类型为String类型时,键值不分大小写的Map类<br>
 *
 * @param <K>
 * @param <V>
 */
public class IgnoreCaseMap<K, V> extends HashMap<K, V> {

    private static final long serialVersionUID = 1L;
    private Map<String, String> keyMap = new HashMap<String, String>();

    /**
     * 构造方法
     */
    public IgnoreCaseMap() {
    }

    /**
     * 构造方法
     */
    public IgnoreCaseMap(int length) {
        super(length);
    }

    /**
     * 构造方法
     *
     * @param map
     */
    public IgnoreCaseMap(Map<K, V> map) {
        super(map.size());
        for (Entry<K, V> entry : map.entrySet()) {
            put(entry.getKey(), entry.getValue());
        }
    }

    /**
     * 根据给定的Key查找Map中存在的Key值
     *
     * @param key
     * @return
     */
    private Object findRealKey(Object key) {
        if (key != null && key instanceof String) {
            String realKey = keyMap.get(key.toString().toLowerCase());
            if (realKey != null)
                return realKey;
        }
        return key;
    }

    /**
     * 获取Key值所映射的Value值<br>
     * 当Key为String类型时不分大小写
     *
     * @see HashMap#get(Object)
     */
    @Override
    public V get(Object key) {
        return super.get(findRealKey(key));
    }

    /**
     * 设置Key键所映射的Value值<br>
     * 当Key为String类型且存在相等(不分大小)的Key值时,使用原来的Key值
     *
     * @see HashMap#put(Object, Object)
     */
    @SuppressWarnings("unchecked")
    @Override
    public V put(K key, V value) {
        if (key != null && key instanceof String) {
            String oldKey = keyMap.put(key.toString().toLowerCase(), key
                    .toString());
            if (oldKey != null) {
                super.remove(oldKey);
            }
        }
        return super.put((K) findRealKey(key), value);
    }

    /**
     * 判断是否包含指定的Key值<br>
     * 当Key为String类型时不分大小写
     *
     * @see HashMap#containsKey(Object)
     */
    @Override
    public boolean containsKey(Object key) {
        return super.containsKey(findRealKey(key));
    }

    /**
     * 删除Key值映射的数据<br>
     * 当Key为String类型时不分大小写
     *
     * @see HashMap#remove(Object)
     */
    @Override
    public V remove(Object key) {
        if (key != null && key instanceof String) {
            keyMap.remove(key.toString().toLowerCase());
        }
        return super.remove(this.findRealKey(key));
    }

}