JAVA redis实现分布式锁工具类

import org.apache.log4j.Logger;

import com.sf.weplay.redis.RedisManager;

public class Lock {
	//默认最长锁5分钟
	private final static int EXPIRED_TIME = 300000;
	
	public static Logger logger = Logger.getLogger(Lock.class);
	
	/**
	 * 锁
	 * @param lockName
	 * @return	true 成功/false 失败
	 */
	public static boolean lock(String lockName) {
		return getLock(lockName, 0);
	}
	
	/**
	 * 解除锁
	 * @param lockName
	 * @return
	 */
	public static void unlock(String lockName) {
		RedisManager.redisManager.del(lockName);
	}
	
	private static boolean getLock(String lockName, Integer count) {
		long lockExpireTime = System.currentTimeMillis() + EXPIRED_TIME;
		String stringOfLockExpireTime = String.valueOf(lockExpireTime);
		boolean gotLock = false;
		
		if(count > 300) {
			return gotLock;
		}
		
		Long i = RedisManager.redisManager.setnx(lockName, stringOfLockExpireTime);
		if (i == 1) {
			gotLock = true;
			return gotLock;
		}
		String value = RedisManager.redisManager.get(lockName, String.class);
		if (value != null && isTimeExpired(value)){
			value = RedisManager.redisManager.getSet(lockName, stringOfLockExpireTime);
			if (value != null && isTimeExpired(value)) {
				gotLock = true;
				return gotLock;
			}
		}
		try {
			Thread.sleep(200);
		} catch (InterruptedException e) {
			// 不处理异常睡眠异常
		}
		return getLock(lockName, ++count);
	}
	
	private static boolean isTimeExpired(String value) {
		return Long.parseLong(value) < System.currentTimeMillis();
	}
}