Redisを使って分散ロックを実現

8980 ワード

/**
 * Redis    
 *    SET resource-name anystring NX EX max-lock-time   
 * 

* Redis SET 。 * http://doc.redisfans.com/string/set.html *

* , Redis 2.6.12 SET , * SET key value [EX seconds] [PX milliseconds] [NX|XX], : *

* EX seconds — key ; * PX milliseconds — key ; * NX — key value , key , SETNX。 * XX — key value , key , SETEX。 *

* SET resource-name anystring NX EX max-lock-time Redis 。 *

* : *

* OK , 。 * NIL , , 。 * * @author zsy * @version 1.0 * @date 2019 8 22 22:21:27 */ public class RedisLock { private static Logger logger = LoggerFactory.getLogger(RedisLock.class); private RedisTemplate redisTemplate; /** * key value , key , SETNX。 */ public static final String NX = "NX"; /** * seconds — key , EXPIRE key seconds */ public static final String EX = "EX"; /** * set */ public static final String OK = "OK"; /** * (ms ) */ private static final long TIME_OUT = 100; /** * (s) */ public static final int EXPIRE = 60; /** * lua */ public static final String UNLOCK_LUA; static { StringBuilder sb = new StringBuilder(); sb.append("if redis.call(\"get\",KEYS[1]) == ARGV[1] "); sb.append("then "); sb.append(" return redis.call(\"del\",KEYS[1]) "); sb.append("else "); sb.append(" return 0 "); sb.append("end "); UNLOCK_LUA = sb.toString(); } /** * key */ private String lockKey; /** * key */ private String lockKeyLog = ""; /** * */ private String lockValue; /** * (s) */ private int expireTime = EXPIRE; /** * (ms) */ private long timeOut = TIME_OUT; /** * */ private volatile boolean locked = false; final Random random = new Random(); /** * * * @param redisTemplate * @param lockKey key(Redis Key) */ public RedisLock(RedisTemplate redisTemplate, String lockKey) { this.redisTemplate = redisTemplate; this.lockKey = lockKey + "_lock"; } /** * , * * @param redisTemplate * @param lockKey key(Redis Key) * @param expireTime ( : ) */ public RedisLock(RedisTemplate redisTemplate, String lockKey, int expireTime) { this(redisTemplate, lockKey); this.expireTime = expireTime; } /** * , * * @param redisTemplate * @param lockKey key(Redis Key) * @param timeOut ( : ) */ public RedisLock(RedisTemplate redisTemplate, String lockKey, long timeOut) { this(redisTemplate, lockKey); this.timeOut = timeOut; } /** * * * @param redisTemplate * @param lockKey key(Redis Key) * @param expireTime ( : ) * @param timeOut ( : ) */ public RedisLock(RedisTemplate redisTemplate, String lockKey, int expireTime, long timeOut) { this(redisTemplate, lockKey, expireTime); this.timeOut = timeOut; } /** * * * @return */ public boolean tryLock() { // key lockValue = UUID.randomUUID().toString(); // , long timeout = timeOut * 1000000; // , long nowTime = System.nanoTime(); while ((System.nanoTime() - nowTime) < timeout) { if (OK.equalsIgnoreCase(this.set(lockKey, lockValue, expireTime))) { locked = true; // return locked; } // seleep(10, 50000); } return locked; } /** * * * @return */ public boolean lock() { lockValue = UUID.randomUUID().toString(); // ( ms) String result = set(lockKey, lockValue, expireTime); locked = OK.equalsIgnoreCase(result); return locked; } /** * * * @return */ public boolean lockBlock() { lockValue = UUID.randomUUID().toString(); while (true) { // ( ms) String result = set(lockKey, lockValue, expireTime); if (OK.equalsIgnoreCase(result)) { locked = true; return locked; } // seleep(10, 50000); } } /** * *

* , : *

* , (non-guessable) , (token)。 * DEL , Lua , , 。 * 。 */ public Boolean unlock() { // // if (locked) { return (Boolean) redisTemplate.execute(new RedisCallback() { @Override public Boolean doInRedis(RedisConnection connection) throws DataAccessException { Object nativeConnection = connection.getNativeConnection(); Long result = 0L; List keys = new ArrayList<>(); keys.add(lockKey); List values = new ArrayList<>(); values.add(lockValue); // if (nativeConnection instanceof JedisCluster) { result = (Long) ((JedisCluster) nativeConnection).eval(UNLOCK_LUA, keys, values); } // if (nativeConnection instanceof Jedis) { result = (Long) ((Jedis) nativeConnection).eval(UNLOCK_LUA, keys, values); } if (result == 0 && !StringUtils.isEmpty(lockKeyLog)) { logger.info("Redis , {} ! :{}", lockKeyLog, System.currentTimeMillis()); } locked = result == 0; return result == 1; } }); } return true; } /** * redisTemplate set *

* SET resource-name anystring NX EX max-lock-time Redis 。 *

* : *

* OK , 。 * NIL , , 。 * * @param key Key * @param value * @param seconds ( ) * @return */ private String set(final String key, final String value, final long seconds) { Assert.isTrue(!StringUtils.isEmpty(key), "key "); return (String) redisTemplate.execute(new RedisCallback() { @Override public String doInRedis(RedisConnection connection) throws DataAccessException { Object nativeConnection = connection.getNativeConnection(); String result = null; if (nativeConnection instanceof JedisCommands) { result = ((JedisCommands) nativeConnection).set(key, value, NX, EX, seconds); } if (!StringUtils.isEmpty(lockKeyLog) && !StringUtils.isEmpty(result)) { logger.info(" {} :{}", lockKeyLog, System.currentTimeMillis()); } return result; } }); } /** * @param millis * @param nanos * @Title: seleep * @Description: * @author yuhao.wang */ private void seleep(long millis, int nanos) { try { Thread.sleep(millis, random.nextInt(nanos)); } catch (InterruptedException e) { logger.info(" :", e); } } public String getLockKeyLog() { return lockKeyLog; } public void setLockKeyLog(String lockKeyLog) { this.lockKeyLog = lockKeyLog; } public int getExpireTime() { return expireTime; } public void setExpireTime(int expireTime) { this.expireTime = expireTime; } public long getTimeOut() { return timeOut; } public void setTimeOut(long timeOut) { this.timeOut = timeOut; } }