package com.xiaopeng.trafficControl.util;

import java.security.MessageDigest;

/**
 * SHA1算法计算散列值的ThreadLocal，避免多线程场景下的线程安全问题<br/>
 */
public class ThreadLocalSHA1 {
	private static final ThreadLocal<MessageDigest> localFormat = new ThreadLocal<MessageDigest>() {
		protected MessageDigest initialValue() {
			try {
				return MessageDigest.getInstance("SHA1");
			} catch (Exception e) {
				System.err.println(SHA1Util.class.getName() + "初始化失败，MessageDigest不支持SHA1Util。");
				e.printStackTrace();

				return null;
			}
		};
	};

	/** 获取当前线程对应的实例 */
	public static MessageDigest current() {
		return localFormat.get();
	}
}