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| package org.zk.naming;
import org.apache.zookeeper.*;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicInteger;
* @auth zhengzhi.ren
* @date 2015/7/24.
*/
public class ZKClient {
private final String rootNode;
private final String serviceNode;
private final String clazz;
private final String businessNode;
private final String hostNode;
protected static ZooKeeper zkConn = null;
private String host = "127.0.0.1:2181";
private int timeout = 500000;
public ZKClient(String rootNode, String serviceNode, String clazz, String businessNode, String hostNode) {
this.rootNode = rootNode;
this.serviceNode = this.rootNode + serviceNode;
this.clazz = clazz;
this.businessNode = this.serviceNode + businessNode;
this.hostNode = this.businessNode + hostNode;
}
* get zk connection
*/
public void connect() {
try {
CountDownLatch semaphore = new CountDownLatch(1);
zkConn = new ZooKeeper(host, timeout, new ConnectWatcher(semaphore));
semaphore.await();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
* create node
*/
public void createNode() {
connect();
if (zkConn == null) {
System.out.println("Warning, Get ZK connection failure!");
}
try {
boolean result = create(rootNode, rootNode, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, new CreateDubboCallback(), "create service node");
if (!result) {
result = create(serviceNode, serviceNode, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, new CreateServiceCallback(), "create service node");
}
if (!result) {
result = create(businessNode, businessNode, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, new CreateProviderCallback(), "create provider node");
}
if (!result) {
create(hostNode, clazz, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
}
} catch (KeeperException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
close();
}
}
private static AtomicInteger index = new AtomicInteger(0);
* a simple load balance implement
* @param path
* @return
* @throws KeeperException
* @throws InterruptedException
*/
public String getData(String path) throws KeeperException, InterruptedException {
String host = null;
String serviceName = null;
try {
connect();
List<String> children = zkConn.getChildren(path, false);
if (children == null || children.size() <= 0)
return null;
if (index.get() >= children.size()) {
index.set(0);
host = children.get(index.get());
} else {
host = children.get(index.getAndIncrement());
}
Stat stat = new Stat();
byte[] data = zkConn.getData(path + "/" + host, null, stat);
serviceName = new String(data);
} finally {
close();
}
return host + serviceName;
}
* Connect success callback
*/
class ConnectWatcher implements Watcher {
private final CountDownLatch semaphore;
private ConnectWatcher(CountDownLatch semaphore) {
this.semaphore = semaphore;
}
@Override
public void process(WatchedEvent watchedEvent) {
if (Event.KeeperState.SyncConnected == watchedEvent.getState()) {
if (Event.EventType.None == watchedEvent.getType() && watchedEvent.getPath() == null) {
System.out.println("ZK connect success!");
semaphore.countDown();
}
}
}
}
* Create a asynchronized node
*
* @param path
* @param data
* @param acl
* @param createMode
* @param cb
* @param ctx
* @throws KeeperException
* @throws InterruptedException
*/
public boolean create(String path, String data, List<ACL> acl, CreateMode createMode, AsyncCallback.StringCallback cb, Object ctx) throws KeeperException, InterruptedException {
Stat rootStat = zkConn.exists(path, false);
boolean result = false;
if (rootStat == null) {
zkConn.create(path, data.getBytes(), acl, createMode, cb, ctx);
result = true;
}
return result;
}
* Create synchronized node
*
* @param path
* @param data
* @param acl
* @param createMode
* @throws KeeperException
* @throws InterruptedException
*/
public void create(String path, String data, List<ACL> acl, CreateMode createMode) throws KeeperException, InterruptedException {
Stat rootStat = zkConn.exists(path, false);
if (rootStat == null) {
zkConn.create(path, data.getBytes(), acl, createMode);
}
}
* Create dubbo node callback by WatcherManager
*/
class CreateDubboCallback implements AsyncCallback.StringCallback {
@Override
public void processResult(int rc, String path, Object ctx, String name) {
System.out.println("Create dubbo node callback by WatcherManager");
if (path == null || "".equals(path)) {
System.out.println("Create " + path + " failure!");
return;
} else {
System.out.println("Create " + path + " success!");
}
try {
create(serviceNode, serviceNode, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, new CreateServiceCallback(), "create service node");
} catch (Exception e) {
e.printStackTrace();
}
}
}
* Create service node callback by WatcherManager
*/
class CreateServiceCallback implements AsyncCallback.StringCallback {
@Override
public void processResult(int rc, String path, Object ctx, String name) {
System.out.println("Create service node callback by WatcherManager");
if (path == null || "".equals(path)) {
System.out.println("Create " + path + " failure!");
return;
} else {
System.out.println("Create " + path + " success!");
}
try {
create(businessNode, businessNode, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, new CreateProviderCallback(), "create provider node");
} catch (Exception e) {
e.printStackTrace();
;
}
}
}
* Create provider node callback by WatcherManager
*/
class CreateProviderCallback implements AsyncCallback.StringCallback {
@Override
public void processResult(int rc, String path, Object ctx, String name) {
System.out.println("Create provide node callback by WatcherManager");
if (path == null || "".equals(path)) {
System.out.println("Create " + path + " failure!");
return;
} else {
System.out.println("Create " + path + " success!");
}
try {
create(hostNode, clazz, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
} catch (Exception e) {
e.printStackTrace();
}
}
}
private void close(){
Runtime.getRuntime().addShutdownHook(new Thread(){
@Override
public synchronized void start() {
try {
zkConn.close();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
}
}
|