com.xiaoleilu.hutool.collection.CaseInsensitiveMap Maven / Gradle / Ivy

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package com.xiaoleilu.hutool.collection;

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

/**
 * 忽略大小写的Map

 * 对KEY忽略大小写，get("Value")和get("value")获得的值相同，put进入的值也会被覆盖
 * 
 * @author Looly
 *
 * @param  键类型
 * @param  值类型
 * @since 3.0.2
 */
public class CaseInsensitiveMap extends HashMap {
	private static final long serialVersionUID = 4043263744224569870L;

	/**
	 * 构造
	 */
	public CaseInsensitiveMap() {
		super();
	}

	/**
	 * 构造
	 * 
	 * @param initialCapacity 初始大小
	 * @param loadFactor 加载因子
	 */
	public CaseInsensitiveMap(int initialCapacity, float loadFactor) {
		super(initialCapacity, loadFactor);
	}

	/**
	 * 构造
	 * 
	 * @param initialCapacity 初始大小
	 */
	public CaseInsensitiveMap(int initialCapacity) {
		this(initialCapacity, 0.75f);
	}

	/**
	 * 构造
	 * 
	 * @param m Map
	 */
	public CaseInsensitiveMap(Map m) {
		super((int) (m.size() / 0.75));
		putAll(m);
	}

	/**
	 * 构造
	 * 
	 * @param loadFactor 加载因子
	 * @param m Map
	 * @since 3.1.2
	 */
	public CaseInsensitiveMap(float loadFactor, Map m) {
		super(m.size(), loadFactor);
		putAll(m);
	}

	@Override
	public V get(Object key) {
		return super.get(lowerCaseKey(key));
	}

	@SuppressWarnings("unchecked")
	@Override
	public V put(K key, V value) {
		return super.put((K) lowerCaseKey(key), value);
	}

	@Override
	public void putAll(Map m) {
		for (Map.Entry entry : m.entrySet()) {
			this.put(entry.getKey(), entry.getValue());
		}
	}

	@Override
	public boolean containsKey(Object key) {
		return super.containsKey(lowerCaseKey(key));
	}

	/**
	 * 将Key转为小写
	 * 
	 * @param key KEY
	 * @return 小写KEy
	 */
	private static Object lowerCaseKey(Object key) {
		if (key instanceof CharSequence) {
			key = key.toString().toLowerCase();
		}
		return key;
	}
}