原生寫法：
package com.gcx.zookeeper;
import java.util.List;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.junit.Before;
import org.junit.Test;
public class Tests {
private static final String connectString ="node01:2181,node02:2181,node03:2181";
private static final int sessionTimeout=60000;
ZooKeeper zkClient = null;
@Before
public void init() throws Exception {
zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
@Override
public void process(WatchedEvent event) {
// 收到事件通知後的回調函數（應該是我們自己的事件處理邏輯）
System.out.println(event.getType() + "---" + event.getPath());
try {
zkClient.getChildren("/", true);
} catch (Exception e) {
}
}
});
}
/**
* 數據的增刪改查
*
* @throws InterruptedException
* @throws KeeperException
*/
// 創建數據節點到zk中
public void testCreate() throws KeeperException, InterruptedException {
// 參數1：要創建的節點的路徑 參數2：節點大數據 參數3：節點的權限 參數4：節點的類型
String nodeCreated = zkClient.create("/eclipse", "hellozk".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
//上傳的數據可以是任何類型，但都要轉成byte[]
}
//判斷znode是否存在
@Test
public void testExist() throws Exception{
Stat stat = zkClient.exists("/eclipse", false);
System.out.println(stat==null?"not exist":"exist");
}
// 獲取子節點
@Test
public void getChildren() throws Exception {
List<String> children = zkClient.getChildren("/", true);
for (String child : children) {
System.out.println(child);
}
Thread.sleep(Long.MAX_VALUE);
}
//獲取znode的數據
@Test
public void getData() throws Exception {
byte[] data = zkClient.getData("/eclipse", false, null);
System.out.println(new String(data));
}
//刪除znode
@Test
public void deleteZnode() throws Exception {
//參數2：指定要刪除的版本，-1表示刪除所有版本
zkClient.delete("/eclipse", -1);
}
//刪除znode
@Test
public void setData() throws Exception {
zkClient.setData("/app1", "imissyou angelababy".getBytes(), -1);
byte[] data = zkClient.getData("/app1", false, null);
System.out.println(new String(data));
}
}
curator框架實現zk客戶端
1.maven座標
<dependencies>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>2.12.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>2.12.0</version>
</dependency>
<dependency>
<groupId>com.google.collections</groupId>
<artifactId>google-collections</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>RELEASE</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.25</version>
</dependency>
</dependencies>
<build>
<plugins>
<!-- java編譯插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
2.測試代碼：
package com.gcxzflgl;
import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.cache.ChildData;
import org.apache.curator.framework.recipes.cache.TreeCache;
import org.apache.curator.framework.recipes.cache.TreeCacheEvent;
import org.apache.curator.framework.recipes.cache.TreeCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;
import org.junit.Test;
/**
* @author gcxzf$
* @version : CuratorTest$, v 0.1 2020/6/26$ 08:24$ gcxzf$ Exp$
*/
public class CuratorTest {
/**
* 創建永久節點
* @throws Exception
*/
@Test
public void createNode() throws Exception {
//定製重試策略（連接客戶端可能存在連接失敗進行重試次數）
// param1 重試間隔
// param2 重試次數
RetryPolicy retryPolicy = new ExponentialBackoffRetry(3000, 3);
//獲取客戶端對象
// param1 連接zk服務列表
// param2 會話超時時間
// param3 連接超時時間
// param4 重試策略
CuratorFramework client = CuratorFrameworkFactory.newClient("node01:2181,node02:2181,node03:2181", 3000, 3000, retryPolicy);
//啓動客戶端
client.start();
//創建永久節點
client
.create()
.creatingParentsIfNeeded() //需要創建父節點
.withMode(CreateMode.PERSISTENT) //節點的類型
.forPath("/hello","words".getBytes()); //節點路徑
//關閉客戶端
client.close();
}
/**
* 修改節點內容
*/
@Test
public void updateNode() throws Exception {
RetryPolicy retryPolicy = new ExponentialBackoffRetry(3000,3);
CuratorFramework client = CuratorFrameworkFactory.newClient("node01:2181,node02:2181,node03:2181", 3000, 3000, retryPolicy);
client.start();
//更新指定節點的數據
client.setData().forPath("/hello","words_holiday".getBytes());
client.close();
}
/**
* 查看節點內容
*/
@Test
public void searchNode() throws Exception {
RetryPolicy retryPolicy = new ExponentialBackoffRetry(3000,3);
CuratorFramework client = CuratorFrameworkFactory.newClient("node01:2181,node02:2181,node03:2181", 3000, 3000, retryPolicy);
client.start();
//獲取指定節點的數據
byte[] bytes = client.getData().forPath("/hello");
System.out.println("目標節點的值:" + new String(bytes));
client.close();
}
/**
* zookeeper的watch機制
* @throws Exception
*/
@Test
public void watchNode() throws Exception {
RetryPolicy policy = new ExponentialBackoffRetry(3000, 3);
CuratorFramework client = CuratorFrameworkFactory.newClient("node01:2181,node02:2181,node03:2181", policy);
client.start();
//設置節點的cache,監聽 hello
TreeCache treeCache = new TreeCache(client, "/hello");
//設置監聽器和處理過程
treeCache.getListenable().addListener(new TreeCacheListener() {
@Override
public void childEvent(CuratorFramework client, TreeCacheEvent event) throws Exception {
ChildData data = event.getData();
if(data !=null){
switch (event.getType()) {
case NODE_ADDED:
System.out.println("NODE_ADDED : "+ data.getPath() +" 數據:"+ new String(data.getData()));
break;
case NODE_REMOVED:
System.out.println("NODE_REMOVED : "+ data.getPath() +" 數據:"+ new String(data.getData()));
break;
case NODE_UPDATED:
System.out.println("NODE_UPDATED : "+ data.getPath() +" 數據:"+ new String(data.getData()));
break;
default:
break;
}
}else{
System.out.println( "data is null : "+ event.getType());
}
}
});
//開始監聽
treeCache.start();
Thread.sleep(50000000);
}
}