SpringBoot整合Zookeeper详细教程
擅长开发Bug的Mr.NaCl 人气:0一、引言
使用原生的zookeeper时候会遇到watcher一次注册生效一次等情况,因此使用curator
curator是Netflix公司开源的一个 zookeeper客户端原生API接口上进行了包装,解决了很多问题并提供Zookeeper分布式锁服务、集群领导选举、共享计数器、缓存机制、分布式队列等的应用的抽象封装
二、引入依赖
<dependency> <groupId>org.apache.zookeeper</groupId> <artifactId>zookeeper</artifactId> <version>3.6.2</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>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>2.0.10</version> </dependency>
三、编写客户端
要改Windows的host文件。host文件位置是C:\Windows\System32\drivers\etc
3.1、ZookeeperConfig
import org.apache.curator.framework.CuratorFramework; import org.apache.curator.framework.CuratorFrameworkFactory; import org.apache.curator.retry.ExponentialBackoffRetry; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration public class ZookeeperConfig { //集群地址,分割不能有空格 在程序里写connectString不可使用ip,必须使用主机名 private String connectString = "master:2181,slave1:2181,slave2:2181"; //连接超时时间 private int sessionTimeout = 5000; //会话存活时间,根据业务灵活指定 private Integer sessionTimeOut=5000; //重试机制时间参数 private Integer sleepMsBetweenRetry=1000; //重试机制重试次数 private Integer maxRetries=3; //命名空间(父节点名称) private String namespace=""; /** - `session`重连策略 - `RetryPolicy retry Policy = new RetryOneTime(3000);` - 说明:三秒后重连一次,只重连一次 - `RetryPolicy retryPolicy = new RetryNTimes(3,3000);` - 说明:每三秒重连一次,重连三次 - `RetryPolicy retryPolicy = new RetryUntilElapsed(1000,3000);` - 说明:每三秒重连一次,总等待时间超过个`10`秒后停止重连 - `RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,3)` - 说明:这个策略的重试间隔会越来越长 - 公式:`baseSleepTImeMs * Math.max(1,random.nextInt(1 << (retryCount + 1)))` - `baseSleepTimeMs` = `1000` 例子中的值 - `maxRetries` = `3` 例子中的值 */ @Bean("curatorClient") public CuratorFramework curatorClient() throws Exception { CuratorFramework client = CuratorFrameworkFactory.builder() .connectString(connectString) .connectionTimeoutMs(sessionTimeout) .sessionTimeoutMs(sessionTimeOut) //session重连策略 .retryPolicy(new ExponentialBackoffRetry(sleepMsBetweenRetry,maxRetries)) //设置命名空间 在操作节点的时候,会以这个为父节点 .namespace(namespace) .build(); client.start(); //注册监听器 ZookeeperWatches watches = new ZookeeperWatches(client); watches.znodeWatcher(); watches.znodeChildrenWatcher(); return client; } }
3.2、ZookeeperWatches
import org.apache.curator.framework.CuratorFramework; import org.apache.curator.framework.recipes.cache.*; import org.apache.zookeeper.data.Stat; public class ZookeeperWatches { private CuratorFramework client; public ZookeeperWatches(CuratorFramework client) { this.client = client; } public void znodeWatcher() throws Exception { NodeCache nodeCache = new NodeCache(client, "/"); nodeCache.start(); nodeCache.getListenable().addListener(new NodeCacheListener() { @Override public void nodeChanged() throws Exception { System.out.println("=======节点改变==========="); String path = nodeCache.getPath(); String currentDataPath = nodeCache.getCurrentData().getPath(); String currentData = new String(nodeCache.getCurrentData().getData()); Stat stat = nodeCache.getCurrentData().getStat(); System.out.println("path:"+path); System.out.println("currentDataPath:"+currentDataPath); System.out.println("currentData:"+currentData); } }); System.out.println("节点监听注册完成"); } public void znodeChildrenWatcher() throws Exception { PathChildrenCache pathChildrenCache = new PathChildrenCache(client, "/",true); pathChildrenCache.start(); pathChildrenCache.getListenable().addListener(new PathChildrenCacheListener() { @Override public void childEvent(CuratorFramework client, PathChildrenCacheEvent event) throws Exception { System.out.println("=======节点子节点改变==========="); PathChildrenCacheEvent.Type type = event.getType(); String childrenData = new String(event.getData().getData()); String childrenPath = event.getData().getPath(); Stat childrenStat = event.getData().getStat(); System.out.println("子节点监听类型:"+type); System.out.println("子节点路径:"+childrenPath); System.out.println("子节点数据:"+childrenData); System.out.println("子节点元数据:"+childrenStat); } }); System.out.println("子节点监听注册完成"); } }
3.3、ZookeeperController
@RestController @RequestMapping(value = "/zookeeper") public class ZookeeperController { @Resource(name = "curatorClient") private CuratorFramework client; @RequestMapping("/createZnode") public String createZnode(){ String path = "/nacl"; String data = "shuaige"; List<ACL> aclList = new ArrayList<>(); Id id = new Id("world", "anyone"); aclList.add(new ACL(ZooDefs.Perms.ALL, id)); try { client.create() .creatingParentsIfNeeded() //没有父节点时 创建父节点 .withMode(CreateMode.PERSISTENT) //节点类型 .withACL(aclList) //配置权限 .forPath(path, data.getBytes()); } catch (Exception e) { e.printStackTrace(); return "节点创建失败"+e.getMessage(); } return "节点创建成功"; } @RequestMapping("/selectZnode") public String selectZnode(){ HashMap<String,String> hashMap=new HashMap(); String path="/nacl"; Stat stat; try { stat = client.checkExists().forPath(path); if (stat == null) { hashMap.put("Error","不存在该节点"); } String dataString = new String(client.getData().forPath(path)); hashMap.put(path, dataString); hashMap.put("stat", stat.toString()); } catch (Exception e) { e.printStackTrace(); } return JSON.toJSONString(hashMap); } @RequestMapping("/selectChildrenZnode") public String selectChildrenZnode(){ Map<String, String> hashMap = new HashMap<>(); String path="/"; try { List<String> list = client.getChildren().forPath(path); for (String s : list) { String dataString = new String(client.getData().forPath(path+s)); hashMap.put(path+s, dataString); } } catch (Exception e) { e.printStackTrace(); } return JSON.toJSONString(hashMap); } @RequestMapping("/setData") public String setData() { String path="/nacl"; String data="big"; Integer version=0; HashMap<String,String> hashMap=new HashMap<>(); try { Stat stat = client.setData().withVersion(version).forPath(path, data.getBytes()); hashMap.put("success", "修改成功"); hashMap.put("version", String.valueOf(stat.getVersion())); } catch (Exception e) { e.printStackTrace(); hashMap.put("error", "修改失败:"+e.getMessage()); } return JSON.toJSONString(hashMap); } @RequestMapping("/delete") public String delete() { HashMap<String,String> hashMap=new HashMap<>(); String path="/nacl"; String data="big"; Integer version=1; try { client.delete().withVersion(version).forPath(path); hashMap.put("success", "删除成功"); } catch (Exception e) { e.printStackTrace(); hashMap.put("error", "删除失败:"+e.getMessage()); } return JSON.toJSONString(hashMap); } @RequestMapping("/createAsyncZnode") public String createAsyncZnode(){ String path = "/nacl"; String data = "shuaige"; try { client.create() .creatingParentsIfNeeded() .withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE) //异步回调 增删改都有异步方法 .inBackground(new BackgroundCallback() { @Override public void processResult(CuratorFramework client, CuratorEvent event) throws Exception { System.out.println("异步回调--获取权限:"+client.getACL().forPath(path)); System.out.println("异步回调--获取数据:"+new String(client.getData().forPath(path))); System.out.println("异步回调--获取事件名称:"+event.getName()); System.out.println("异步回调--获取事件类型:"+event.getType()); } }) .forPath(path, data.getBytes()); } catch (Exception e) { e.printStackTrace(); return "节点创建失败"+e.getMessage(); } return "节点创建成功"; } }
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