Springboot-Zookeeper(curator)实现分布式锁、分布式ID等_springboot curator

        Zookeeper 的原生客户端使用起来比较繁琐，一般生成环境很少使用。curator 在外面封装了一层，使用起来更加方便，并且还提供了常用的场景，比如 leader 选举，分布式锁，分布式队列。

        官方文档说明：Curator 2.x.x-兼容两个zk 3.4.x 和zk 3.5.x，Curator 3.x.x-兼容兼容zk 3.5。

        Curator官网：Apache Curator –

 一、引入依赖

        <!-- web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
 
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
 
        <!-- fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.83</version>
        </dependency>
 
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>5.2.0</version>
        </dependency>
 
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>5.2.0</version>
        </dependency>
 
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-client</artifactId>
            <version>5.2.0</version>
        </dependency>

二、application.yml配置

zookeeper:
  connect:
    address: IP:2181 #zookeeper连接地址
    connection-time-out: 10000 #连接超时时间 毫秒
    session-time-out: 10000 #session超时时间 毫秒
    sleep-time-out: 3000 #重试初试时间 毫秒
    max-retries: 3 #重试次数
    wait-time: 20 #连接等待时间 毫秒
    name-space: curator #命名空间

三、配置文件

/**
 * @Description: curator-congif
 * @create by meng on 13:56 2022/10/26
 */
@Configuration
public class CuratorConfig {
 
	@Value("${zookeeper.connect.address}")
	private String connectStr;
	@Value("${zookeeper.connect.connection-time-out}")
	private int connectionTimeout;
	@Value("${zookeeper.connect.session-time-out}")
	private int sessionTimeout;
	@Value("${zookeeper.connect.sleep-time-out}")
	private int sleepTimeOut;
	@Value("${zookeeper.connect.max-retries}")
	private int maxRetries;
	@Value("${zookeeper.connect.name-space}")
	private String namespace;
 
	/**
	 * 初始化curator客户端
	 * @return
	 */
	@Bean
	public CuratorFramework getCuratorClient() {
		RetryPolicy retryPolicy = new ExponentialBackoffRetry(sleepTimeOut, maxRetries);
		CuratorFramework client = CuratorFrameworkFactory.builder()
				.connectString(connectStr)
				.connectionTimeoutMs(connectionTimeout)
				.sessionTimeoutMs(sessionTimeout)
				.namespace(namespace)
				.retryPolicy(retryPolicy).build();
		client.start();
		return client;
	}
}

四、接口服务

/**
 * @Description: CuratorService
 * @create by meng on 13:57 2022/10/26
 */
@Service
public class CuratorService {
 
	@Value("${zookeeper.connect.wait-time}")
	private int waitTime;
	@Autowired
	private CuratorFramework curatorClient;
 
	/**
	 * 创建节点
	 * @param path
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public String createNode(String path, String data) throws Exception {
		String hostAddress = InetAddress.getLocalHost().getHostAddress();
		String serviceInstance = "prometheus" + "-" +  hostAddress + "-";
		String nodePath = curatorClient.create().creatingParentsIfNeeded()
				.forPath(path + "/" + serviceInstance, data.getBytes(StandardCharsets.UTF_8));
		return nodePath;
	}
 
	/**
	 * 创建指定类型的无序节点(持久或临时)
	 * @param nodeType
	 * @param path
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public String createTypeNode(CreateMode nodeType, String path, String data) throws Exception {
		String nodePath = curatorClient.create().creatingParentsIfNeeded().withMode(nodeType)
				.forPath(path, data.getBytes(StandardCharsets.UTF_8));
		return nodePath;
	}
 
	/**
	 * 创建指定类型的有序节点
	 * @param nodeType
	 * @param path
	 * @param data
	 * @return
	 */
	public String createTypeSeqNode(CreateMode nodeType, String path, String data) throws Exception {
		String nodePath = curatorClient.create().creatingParentsIfNeeded().withProtection().withMode(nodeType)
				.forPath(path, data.getBytes(StandardCharsets.UTF_8));
		return nodePath;
	}
 
	/**
	 * 设置值
	 * @param path
	 * @param data
	 * @return
	 */
	public Stat setData(String path, String data) throws Exception {
		int version = 0; // 当前节点的版本信息
		Stat stat = new Stat();
		curatorClient.getData().storingStatIn(stat).forPath(path);
		version = stat.getVersion();
		// 如果版本信息不一致，说明当前数据被修改过，则修改失败程序报错
		curatorClient.setData().withVersion(version).forPath(path, data.getBytes(StandardCharsets.UTF_8));
		return stat;
	}
 
	/**
	 * 异步设置值
	 * @param path
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public Stat setDataAsync(String path, String data) throws Exception {
		CuratorListener listener = new CuratorListener() {
			@Override
			public void eventReceived(CuratorFramework client, CuratorEvent event) throws Exception {
				//examine event for details
			}
		};
		curatorClient.getCuratorListenable().addListener(listener);
		Stat stat = curatorClient.setData().inBackground().forPath(path, data.getBytes(StandardCharsets.UTF_8));
		return stat;
	}
 
	/**
	 * 删除节点
	 * @param path
	 * @throws Exception
	 */
	public void deleteNode(String path) throws Exception {
//		curatorClient.delete().deletingChildrenIfNeeded().forPath(path);
		// deletingChildrenIfNeeded如果有子节点一并删除
		// guaranteed必须成功比如网络抖动时造成命令失败
		curatorClient.delete().guaranteed().deletingChildrenIfNeeded().inBackground(new BackgroundCallback() {
			@Override
			public void processResult(CuratorFramework curatorFramework, CuratorEvent curatorEvent) throws Exception {
				System.out.println("删除成功");
				// { "path":"/javacui/p1","resultCode":0,"type":"DELETE"}
				System.out.println(JSON.toJSONString(curatorEvent, true));
			}
		}).forPath(path);
	}
 
	/**
	 * 查询节点
	 * @param path
	 * @throws Exception
	 */
	public Stat getPath(String path) throws Exception {
		// 查内容
		byte[] data = curatorClient.getData().forPath(path);
		System.out.println(new String(data));
 
		// 查状态
		Stat stat = new Stat();
		curatorClient.getData().storingStatIn(stat).forPath(path);
		System.out.println(JSON.toJSONString(stat, true));
		return stat;
	}
 
	/**
	 * 查看子节点
	 * @param path
	 * @return
	 * @throws Exception
	 */
	public List<String> watchedGetChildren(String path) throws Exception {
		List<String> childrenList = curatorClient.getChildren().watched().forPath(path);
		return childrenList;
	}
 
	/**
	 * 查看子节点
	 * @param path
	 * @param watcher
	 * @return
	 * @throws Exception
	 */
	public List<String> watchedGetChildren(String path, Watcher watcher) throws Exception {
		List<String> childrenList = curatorClient.getChildren().usingWatcher(watcher).forPath(path);
		return childrenList;
	}
 
	/**
	 * 创建分布式锁
	 * @return
	 */
	public void getLock(String path) {
		InterProcessLock lock = new InterProcessMutex(curatorClient, path);
		try {
			if (lock.acquire(waitTime, TimeUnit.MILLISECONDS)) {
				System.out.println("to do something");
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				lock.release();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}
 
	/**
	 * 获取分布式ID
	 * @param path
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public String getDistributedId(String path, String data) throws Exception {
		String seqNode = this.createTypeSeqNode(CreateMode.EPHEMERAL_SEQUENTIAL, path, data);
		System.out.println(seqNode);
		int index = seqNode.lastIndexOf(path);
		if (index >= 0) {
			index += path.length();
			return index <= seqNode.length() ? seqNode.substring(index) : "";
		}
		return seqNode;
	}
 
}

五、测试相关操作

package org.meng.zookeeperCurator;
 
import com.alibaba.fastjson.JSON;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.api.BackgroundCallback;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.zookeeper.data.Stat;
import org.junit.jupiter.api.Test;
import org.meng.zookeeperCurator.service.CuratorService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
 
import java.net.InetAddress;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.List;
 
@SpringBootTest
class ZookeeperCuratorApplicationTests {
 
	private static final String path = "/zkTest";
 
	@Autowired
	private CuratorService curatorService;
 
	@Test
	void contextLoads() {
	}
 
	// 创建节点,赋值
	@Test
	public void createPath() throws Exception {
		curatorService.createNode(path, "测试zookeeper");
	}
 
	// 修改数据
	@Test
	public void setData() throws Exception {
		String hostAddress = InetAddress.getLocalHost().getHostAddress();
		String serviceInstance = "prometheus" + "-" +  hostAddress + "-";
		curatorService.setData(path + "/" + serviceInstance, "测试zookeeper修改");
	}
 
	// 查询节点
	@Test
	public void getPath() throws Exception {
		String hostAddress = InetAddress.getLocalHost().getHostAddress();
		String serviceInstance = "prometheus" + "-" +  hostAddress + "-";
		curatorService.getPath(path + "/" + serviceInstance);
	}
 
	// 查询子节点
	@Test
	public void getPaths() throws Exception {
		List<String> list = curatorService.watchedGetChildren(path);
		System.out.println(list);
	}
 
	// 删除节点
	@Test
	public void deletePath() throws Exception {
		String hostAddress = InetAddress.getLocalHost().getHostAddress();
		String serviceInstance = "prometheus" + "-" +  hostAddress + "-";
		curatorService.deleteNode(path + "/" + serviceInstance);
	}
 
	// 负载均衡
	@Test
	public void loadPath() throws Exception {
		List<String> instanceList = curatorService.watchedGetChildren(path);
		Collections.sort(instanceList);
		String hostAddress = InetAddress.getLocalHost().getHostAddress();
		int instanceNo = 0;
		if (hostAddress !=  null) {
			for (int i=0; i<instanceList.size(); i++) {
				if (instanceList.get(i).split("-")[1].equals(hostAddress)) {
					instanceNo = i;
				}
			}
		} else {
			System.out.println("获取本地IP失败");
		}
		System.out.println("实例总数:"+instanceList.size()+", 第"+instanceNo+"个实例");
	}
 
	@Test
	public void getLock() throws Exception {
		curatorService.getLock(path +"/zkLock");
	}
 
	@Test
	public void getDistributedId() throws Exception {
		String zkDemoId = curatorService.getDistributedId(path + "/distributedId", "zkDemoId");
	}
 
}