zookeeper有java兩種客戶端 zookeeper和CuratorFramework
一：線程不安全時候的代碼，生成訂單號爲例子
final static CuratorFramework client = CuratorFrameworkFactory.builder()
.connectString("120.77.156.44:2181")
.retryPolicy(new ExponentialBackoffRetry(100,1))
.build();
static int num =1;
public static void main(String[] args) throws InterruptedException {
ExecutorService executorService = Executors.newCachedThreadPool();
final CountDownLatch countDownLatch = new CountDownLatch(1);
for(int i=0;i<10;i++) {
executorService.submit(new Runnable() {
@Override
public void run() {
try {
countDownLatch.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"---->"+getOrder());
}
});
}
countDownLatch.countDown();
executorService.shutdown();
}
//生成訂單號的鎖
public static String getOrder() {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int k = num++;
return "testOrder"+k;
}
運行結果爲：
二：用CuratorFramework 來實現zook鎖
pom:
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>2.9.0</version>
</dependency>
java:
final static CuratorFramework client = CuratorFrameworkFactory.builder()
.connectString("120.77.156.44:2181")
.retryPolicy(new ExponentialBackoffRetry(100,1))
.build();
static int num =1;
public static void main(String[] args) throws InterruptedException {
client.start();
ExecutorService executorService = Executors.newCachedThreadPool();
final CountDownLatch countDownLatch = new CountDownLatch(1);
final InterProcessMutex lock = new InterProcessMutex(client, "/test11");
for(int i=0;i<10;i++) {
executorService.submit(new Runnable() {
@Override
public void run() {
try {
countDownLatch.await();
try {
lock.acquire();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"---->"+getOrder());
try {
lock.release();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
countDownLatch.countDown();
executorService.shutdown();
}
//生成訂單號的鎖
public static String getOrder() {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int k = num++;
return "testOrder"+k;
}
運行結果：
三：zookeeper客戶端鎖（簡單粗暴版）
pom:
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.12</version>
</dependency>
java:
static ZooKeeper zk = null;
static{
try {
zk=new ZooKeeper("120.77.156.44:2181", 3000, new Watcher() {
public void process(WatchedEvent event) {
System.out.println(event);
}
});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) throws InterruptedException, KeeperException {
ExecutorService executorService = Executors.newCachedThreadPool();
final CountDownLatch countDownLatch = new CountDownLatch(1);
for(int i=0;i<10;i++) {
executorService.submit(new Runnable() {
@Override
public void run() {
try {
countDownLatch.await();
lock();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"---->"+getOrder());
unlock();
}
});
}
countDownLatch.countDown();
executorService.shutdown();
}
static int num =1;
public static String getOrder() {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int k = num++;
return "testOrder"+k;
}
public static void lock() {
try {
zk.create("/test/lock", "test".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
} catch (Exception e) {
try {
Thread.sleep(100);
} catch (InterruptedException e1) {
}
lock();
}
}
public static void unlock() {
try {
zk.delete("/test/lock", -1);
} catch (Exception e) {
System.out.println("delete no");
}
// System.out.println("delete success");
}
運行結果：
4:zookeeper鎖
public class MyLock implements Watcher{
static String root = "/test/lock";
ZooKeeper zKeeper;
String path;
private String currentNode;
private String waitNode;
CountDownLatch latch;
public MyLock(String path,String host) {
try {
zKeeper = new ZooKeeper(host, 1000, this);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
this.path = path;
try {
Stat node = zKeeper.exists(root, false);
if(node==null) {
zKeeper.create(root, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
}
} catch (KeeperException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void lock(){
try {
currentNode = zKeeper.create(root+"/"+path, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
} catch (KeeperException | InterruptedException e) {
e.printStackTrace();
}
try {
List<String> lockObjectNode = zKeeper.getChildren(root, false);
Collections.sort(lockObjectNode);
if(currentNode.equals(root+"/"+lockObjectNode.get(0))) {
return;
}else {
//截取 /test/lock/lock00001 中的lock00001
String key = currentNode.substring(currentNode.lastIndexOf("/")+1);
//找到鎖的位置
int index = Collections.binarySearch(lockObjectNode, key);
waitNode = lockObjectNode.get(index-1); //獲取等待節點
Stat stat = zKeeper.exists(root+"/"+waitNode, true);
if(null!=stat) {
latch = new CountDownLatch(1);
this.latch.await(5000,TimeUnit.MILLISECONDS);
}
}
} catch (KeeperException | InterruptedException e) {
e.printStackTrace();
}
}
public void unLock() {
try {
//刪除當前的節點
zKeeper.delete(currentNode, -1);
currentNode=null;
zKeeper.close();
} catch (InterruptedException | KeeperException e) {
e.printStackTrace();
}
}
@Override
public void process(WatchedEvent arg0) {
if(null!=latch) {
latch.countDown();
}
}
}