<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.14</version>
</dependency>
private CuratorFramework client;
public void init() {
client = CuratorFrameworkFactory.builder()
.connectString("localhost:2181")
.sessionTimeoutMs(5000)
.retryPolicy(new ExponentialBackoffRetry(1000, 3))
.build();
client.start();
}
public void acquireLock(String lockPath) throws Exception {
String lockNode = client.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL_SEQUENTIAL).forPath(lockPath);
while (true) {
List<String> lockNodes = client.getChildren().forPath(lockPath);
Collections.sort(lockNodes);
if (lockNode.equals(lockPath + "/" + lockNodes.get(0))) {
break;
} else {
client.getChildren().usingWatcher(watcher).forPath(lockPath);
synchronized (watcher) {
watcher.wait();
}
}
}
}
public void releaseLock(String lockPath) throws Exception {
client.delete().forPath(lockPath);
synchronized (watcher) {
watcher.notifyAll();
}
}
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>3.6.0</version>
</dependency>
private Jedis jedis;
public void init() {
jedis = new Jedis("localhost");
}
public boolean acquireLock(String lockKey, String requestId, int expireTime) {
String result = jedis.set(lockKey, requestId, "NX", "PX", expireTime);
return "OK".equals(result);
}
public boolean releaseLock(String lockKey, String requestId) {
String script = "if redis.call('get', KEYS[1]) == ARGV[1] " +
"then " +
"return redis.call('del', KEYS[1]) " +
"else " +
"return 0 " +
"end";
Object result = jedis.eval(script, Collections.singletonList(lockKey), Collections.singletonList(requestId));
return result.equals(1L);
}
