com.jeesuite.common2.lock.redis.RedisDistributeLock Maven / Gradle / Ivy
package com.jeesuite.common2.lock.redis;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import com.jeesuite.common2.lock.LockException;
import redis.clients.jedis.Jedis;
/**
* 基于redis的锁
* @description
* @author vakin
* @date 2018年3月22日
*/
public class RedisDistributeLock implements Lock {
private static RedisLockCoordinator coordinator = new RedisLockCoordinator();
private static final String LOCK_KEY_PREFIX = "dlock:";
private static final int _DEFAULT_MAX_WAIT = 30;
private static final int _DEFAULT_MAX_WAIT_LIMIT = 20;
private String lockName;
private String eventId;
private int maxWaitLimt;
private int timeoutSeconds;
private int maxLiveSeconds;
private Jedis client;
/**
* 默认最大存活时间30秒,最大排队等待数：20
* @param lockName
*/
public RedisDistributeLock(String lockName) {
this(lockName, _DEFAULT_MAX_WAIT,_DEFAULT_MAX_WAIT_LIMIT);
}
/**
* 默认最大排队等待数：20
* @param lockName
* @param timeoutSeconds
*/
public RedisDistributeLock(String lockName,int timeoutSeconds) {
this(lockName,timeoutSeconds,_DEFAULT_MAX_WAIT_LIMIT);
}
/**
*
* @param lockName
* @param timeoutSeconds 锁超时时间（秒）
* @param maxWaitLimt 最大排队等待数限制
*/
public RedisDistributeLock(String lockName,int timeoutSeconds,int maxWaitLimt) {
this.lockName = LOCK_KEY_PREFIX + lockName;
this.timeoutSeconds = timeoutSeconds;
this.maxLiveSeconds = timeoutSeconds + 1;
this.eventId = coordinator.buildEvenId();
this.maxWaitLimt = maxWaitLimt;
}
@Override
public void lock() {
try {
tryLock(timeoutSeconds, TimeUnit.SECONDS);
} catch (InterruptedException e) {}
}
@Override
public void lockInterruptibly() throws InterruptedException {
}
@Override
public boolean tryLock() {
try {
return tryLock(0, TimeUnit.SECONDS);
} catch (Exception e) {
return false;
}
}
@Override
public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
boolean getLock = true;
client = coordinator.getRedisClient();
try {
Long waitCount = client.lpush(lockName, eventId);
client.expire(lockName, maxLiveSeconds);
if(waitCount == 1){
return getLock;
}
if(waitCount > maxWaitLimt){
getLock = false;
throw new LockException(String.format("Lock[%s] Too many wait", lockName));
}
if(timeout == 0){
getLock = false;
return getLock;
}
//await
getLock = coordinator.await(lockName,eventId, unit.toMillis(timeout));
if(!getLock){
throw new LockException(String.format("Lock[%s] Timeout", lockName));
}
return getLock;
} finally {
if(!getLock)client.lrem(lockName, 1, eventId);
}
}
@Override
public void unlock() {
if(client == null)throw new LockException("cant't unlock,because Lock not found");
try {
client.lrem(lockName, 1, eventId);
coordinator.notifyNext(client,lockName);
} finally {
if(client != null)coordinator.release(client);
}
}
@Override
public Condition newCondition() {
return null;
}
}