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my-distributed-lock
There is a newer version: 1.2.2
package com.zhuang.distributedlock.lock;


import com.zhuang.distributedlock.config.LockProperties;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.scripting.support.ResourceScriptSource;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

@Slf4j
public class RedisDistributedLock implements Lock, InitializingBean {

    @Autowired
    private StringRedisTemplate redisTemplate;

    private DefaultRedisScript lockScript; // 锁脚本
    private DefaultRedisScript unlockScript; // 解锁脚本

    private ThreadLocal threadKeyId = new ThreadLocal() {
        @Override
        protected String initialValue() {
            return UUID.randomUUID().toString().replace("-", "");
        }
    };

    /**
     * 生成操作redis的lua脚本操作实例
     */
    private void initialize() {
        //lock script
        lockScript = new DefaultRedisScript();
        lockScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("lock/lock.lua")));
        lockScript.setResultType(Long.class);
        log.debug("初始化加锁脚本成功:\n:{}", lockScript.getScriptAsString());

        //unlock script
        unlockScript = new DefaultRedisScript();
        unlockScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("lock/unlock.lua")));
        unlockScript.setResultType(Long.class);
        log.debug("初始化释放锁脚本成功:\n:{}", unlockScript.getScriptAsString());
    }

    public String lock(String lockKey, LockProperties lockProperties) {
        Assert.notNull(lockKey, "lockKey can't be null");
        String key = getLockKey(lockKey, lockProperties);
        List keyList = new ArrayList();
        keyList.add(key);
        keyList.add(threadKeyId.get());
        int lockTryCount = 0;//获取锁次数
        log.debug("加锁成功，lockKey:{},准备执行业务操作", lockKey);
        while (true) {
            if (lockProperties.getRetryCount() > 0 && lockTryCount > lockProperties.getRetryCount()) {
                //加锁失败超过设定重试次数，抛出异常表示加锁失败
                throw new RuntimeException("access to distributed lockKey more than retries：" + lockProperties.getRetryCount());
            }
            if (lockTryCount > 0) {
                log.debug("重试获取锁:{}操作:{}次", lockKey, lockTryCount);
            }
            if (redisTemplate.execute(lockScript, keyList, String.valueOf(lockProperties.getExpiredTime())) > 0) {
                //返回结果大于0，表示加锁成功
                log.debug("加锁成功，lockKey:{},准备执行业务操作", lockKey);
                return lockKey;
            } else {
                try {
                    Thread.sleep(lockProperties.getRetryInterval());
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
            lockTryCount++;
        }
    }

    public boolean unlock(String lock, LockProperties lockProperties) {
        Assert.notNull(lock, "lock can't be null");
        final String key = getLockKey(lock, lockProperties);
        List keyList = new ArrayList();
        keyList.add(key);
        keyList.add(threadKeyId.get());
        redisTemplate.execute(unlockScript, keyList);
        log.debug("成功释放锁，lockKey:{}", lock);
        return true;
    }

    /**
     * 生成key
     *
     * @param lock
     * @return
     */
    private String getLockKey(String lock, LockProperties lockProperties) {
        if (StringUtils.isEmpty(lockProperties.getLockPre())) {
            return lock;
        }
        StringBuilder sb = new StringBuilder();
        sb.append(lockProperties.getLockPre()).append(":").append(lock);
        return sb.toString();
    }

    public void afterPropertiesSet() {
        initialize();
    }
}