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Redis分布式锁Java实现类

Redis 分布式锁 Java 实现类

 

package com.utils;

import java.util.Collections;
import java.util.UUID;


import redis.clients.jedis.Jedis;


public class RedisTool {


</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">final</span> String LOCK_SUCCESS = "OK"<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">final</span> String SET_IF_NOT_EXIST = "NX"<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">final</span> String SET_WITH_EXPIRE_TIME = "PX"<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">final</span> String SCRIPT = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end"<span style="color: rgba(0, 0, 0, 1)">;
</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">final</span> Long RELEASE_SUCCESS = 1L<span style="color: rgba(0, 0, 0, 1)">;

</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> test</span>
<span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">int</span> count = 0<span style="color: rgba(0, 0, 0, 1)">;

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 获取请求Id 
 * </span><span style="color: rgba(128, 128, 128, 1)">@return</span><span style="color: rgba(0, 128, 0, 1)"> 返回UUID
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span><span style="color: rgba(0, 0, 0, 1)"> String getRequestId(){
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> UUID.randomUUID().toString();
}

</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 尝试获取分布式锁
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> jedis Redis客户端
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> lockKey 锁
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> requestId 请求标识
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> expireTime 超期时间
 * </span><span style="color: rgba(128, 128, 128, 1)">@return</span><span style="color: rgba(0, 128, 0, 1)"> 是否获取成功
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span> tryGetDistributedLock(Jedis jedis, String lockKey, String requestId, <span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> expireTime) {

    String result </span>=<span style="color: rgba(0, 0, 0, 1)"> jedis.set(lockKey, requestId, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, expireTime);

    </span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (LOCK_SUCCESS.equals(result)) {
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">true</span><span style="color: rgba(0, 0, 0, 1)">;
    }
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">;
}


</span><span style="color: rgba(0, 128, 0, 1)">/**</span><span style="color: rgba(0, 128, 0, 1)">
 * 释放分布式锁
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> jedis Redis客户端
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> lockKey 锁
 * </span><span style="color: rgba(128, 128, 128, 1)">@param</span><span style="color: rgba(0, 128, 0, 1)"> requestId 请求标识
 * </span><span style="color: rgba(128, 128, 128, 1)">@return</span><span style="color: rgba(0, 128, 0, 1)"> 是否释放成功
 </span><span style="color: rgba(0, 128, 0, 1)">*/</span>
<span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">boolean</span><span style="color: rgba(0, 0, 0, 1)"> releaseDistributedLock(Jedis jedis, String lockKey, String requestId) {

    Object result </span>=<span style="color: rgba(0, 0, 0, 1)"> jedis.eval(SCRIPT, Collections.singletonList(lockKey), Collections.singletonList(requestId));

    </span><span style="color: rgba(0, 0, 255, 1)">if</span><span style="color: rgba(0, 0, 0, 1)"> (RELEASE_SUCCESS.equals(result)) {
        </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">true</span><span style="color: rgba(0, 0, 0, 1)">;
    }
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> main(String[] args) {
    RedisTool redisTool </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> RedisTool();
    redisTool.testDistributedLock();
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> testDistributedLock() {
    </span><span style="color: rgba(0, 0, 255, 1)">for</span> (<span style="color: rgba(0, 0, 255, 1)">int</span> i = 0; i &lt; 10; i++<span style="color: rgba(0, 0, 0, 1)">) {
        </span><span style="color: rgba(0, 0, 255, 1)">new</span> Thread(<span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> Runnable() {

            @Override
            </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> run() {
                Jedis jedis </span>= <span style="color: rgba(0, 0, 255, 1)">new</span> Jedis("localhost"<span style="color: rgba(0, 0, 0, 1)">);
                String lockKey </span>= "lock"<span style="color: rgba(0, 0, 0, 1)">;
                String requestId </span>=<span style="color: rgba(0, 0, 0, 1)"> getRequestId();
                </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 加锁</span>
                <span style="color: rgba(0, 0, 255, 1)">if</span> (tryGetDistributedLock(jedis, lockKey, requestId, 10<span style="color: rgba(0, 0, 0, 1)">)) {
                    count</span>++<span style="color: rgba(0, 0, 0, 1)">;
                    System.out.println(requestId </span>+ ":" +<span style="color: rgba(0, 0, 0, 1)"> count);
                    </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 解锁</span>



                        releaseDistributedLock(jedis, lockKey, requestId);
} else {
System.out.println(requestId + ": tryGetDistributedLock fail");
}


            }
        });
    }
}



}

 

 

转自：http://www.importnew.com/27477.html