JZTXT

分布式锁-lua脚本

发布时间 2023-08-18 16:38:45作者: 我没有出家
// 工具类
@Component
public class RedisLock {
    @Autowired
    private RedisTemplate redisTemplate;

    // 时间轮异步定时执行
    private HashedWheelTimer timer = new HashedWheelTimer();

    private DefaultRedisScript addTimeScript;
    {
        DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>();
        redisScript.setResultType(Long.class);
        redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("redis/redis_lock.lua")));
        this.addTimeScript = redisScript;
    }


    /***
     * @Description: 获取锁并设置过期时间
     * @Author: szc
     * @Date: 2023/8/15 19:52
     * @Params [key, expireSecond]
     * @Return boolean
     */
    public boolean tryLock(String key, long expireSecond){
        DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>();
        redisScript.setResultType(Long.class);
        redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("redis/redis_lock.lua")));
        Long isSuccess = (Long) redisTemplate.execute(redisScript, Arrays.asList(key), expireSecond);
        return isSuccess != null && isSuccess == 1L;
    }

    /***
     * @Description: 释放锁，删除key
     * @Author: szc
     * @Date: 2023/8/15 19:52
     * @Params [key, expireSecond]
     * @Return boolean
     */
    public boolean unLock(String key){
        DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>();
        redisScript.setResultType(Long.class);
        redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("redis/redis_unlock.lua")));
        Long isSuccess = (Long) redisTemplate.execute(redisScript, Arrays.asList(key));
        return isSuccess != null && isSuccess == 1L;

    }
    /***
     * @Description: 自增1
     * @Author: szc
     * @Date: 2023/8/15 19:52
     * @Params [key, expireSecond]
     * @Return boolean
     */
    public boolean incrKey(String key, long expireSecond){
        DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>();
        redisScript.setResultType(Long.class);
        redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("redis/redis_incr_expire.lua")));
        Long isSuccess = (Long) redisTemplate.execute(redisScript, Arrays.asList(key), expireSecond);
        Object num = redisTemplate.opsForValue().get(key);
        System.out.println("incrKey========="+num);
        return isSuccess != null && isSuccess == 1L;

    }
    /***
     * @Description : key过期前未执行完，自动续期，增加过期时间
     * @Author: szc
     * @Date: 2023/8/15 22:07
     * @Params [key, time]
     * @Return void
     */
    public void addTime(String key, long time) {
        timer.newTimeout(
                timerTask -> {
                    //意思就是执行luaaa,key给KEYS[1]，time给ARGV[1]
                    Long execute = (Long) redisTemplate.execute(addTimeScript, Arrays.asList(key), time);
                    if (execute == 0) {
                        ThreadUtils.threadInfo("当前key还存在，自动续期。");
                        addTime(key, time);
                    } else {
                        ThreadUtils.threadInfo("key不存在了，不需要续期");
                    }
                }, time / 3, TimeUnit.SECONDS);//time的三分之一时间去执行看有没有key，有重置过期时间,没有就什么都不做。
    }
}

src\main\resources\redis\redis_incr_expire.lua

-- 每次增加1，设置过期时间
local result = tonumber(redis.call('incr', KEYS[1]))
if(result == 1) then
    redis.call('expire', KEYS[1], ARGV[1])
    return result
else
    return result
end

　　src\main\resources\redis\redis_lock.lua

-- 使用中的坑：需要重写redistemplate , 不然返回的都是0
--  eval "return tonumber(redis.call('setnx', 'lock_test', 'lock_test'))" 0     对应下一行执行
local result = tonumber(redis.call('setnx', KEYS[1], ARGV[1]))
if(result == 1) then
    redis.call('expire', KEYS[1], ARGV[1])
    return result
else
    return result
end

　\src\main\resources\redis\redis_unlock.lua

-- 15 为设置的过期时间，可以java参数传递，使用ARGV[1]接收
if(redis.call('get', KEYS[1]) == '15') then
    return redis.call('del', KEYS[1])
else
    return 0
end　

依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

　　yml

spring:
  redis:
    host: localhost
    port: 6379
    password:

使用

public class RedisLockController {
    @Autowired
    private RedisLock redisLock;

    @RequestMapping("lock")
    public void lock(){
        long expireSecond = 15;
        String key = "lock_test";
        boolean lock = redisLock.tryLock(key, expireSecond);
        if(lock){
            try {
                // key过期前未执行完，自动续期，增加过期时间
                redisLock.addTime(key,expireSecond);
                log.info("获取锁成功。。。。。。");
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }finally {
                boolean unLock = redisLock.unLock(key);
                if(unLock){
                    log.info("释放锁成功！");
                }else {
                    log.info("释放锁失败！");
                }
            }
        }else {
            log.info("获取锁失败。");
        }

    }
    @RequestMapping("incrKey")
    public void incrKey(){
        redisLock.incrKey("num_test", 60);
    }