Curator Framework操作zookeeper(1)-基本操作
1 maven依赖
3.4.11 4.1.0
org.apache.zookeeper zookeeper ${zookeeper.version} org.slf4j slf4j-log4j12 log4j log4j org.apache.curator curator-recipes ${apache.curator.version} org.apache.curator curator-framework ${apache.curator.version} slf4j-api org.slf4j zookeeper org.apache.zookeeper
2 工具类
import cn.sun.curator.listener.AbstractNodeCacheListener; import cn.sun.curator.listener.SessionConnectionStateListener; import cn.sun.util.PropertiesUtil; import org.apache.curator.RetryPolicy; import org.apache.curator.framework.CuratorFramework; import org.apache.curator.framework.CuratorFrameworkFactory; import org.apache.curator.framework.api.ACLBackgroundPathAndBytesable; import org.apache.curator.framework.api.BackgroundPathAndBytesable; import org.apache.curator.framework.api.BackgroundPathable; import org.apache.curator.framework.recipes.cache.*; import org.apache.curator.retry.ExponentialBackoffRetry; import org.apache.zookeeper.CreateMode; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.ZooDefs; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.List; import java.util.Properties; /** * zk工具类 */ public class ZkUtil { private static final Logger log = LoggerFactory.getLogger(ZkUtil.class); public static String NAMESPACE = "chy"; public static Properties pu = PropertiesUtil.loadProperties("classpath:zkconfig.properties"); public static CuratorFramework client; public static String env = "DEV"; public static synchronized void initialize() { String zkhost = null; int sessionTimeout = 60000; int connTimeout = 3000; try { log.info("read classpath:zkconfig.properties, env: " + env); if (pu != null) { zkhost = pu.getProperty(env + "_ZK_SERVER"); sessionTimeout = Integer.valueOf(pu.getProperty("sessionTimeout", "60000")).intValue(); connTimeout = Integer.valueOf(pu.getProperty("connTimeout", "3000")).intValue(); client = createClient(zkhost, sessionTimeout, connTimeout, NAMESPACE); } } catch (Exception e) { log.error("init zkUtil error!", e); } } public static CuratorFramework createClient(String zkhost, int sessionTimeout, int connTimeout, String nameSpace) { CuratorFramework client = null; RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3); client = CuratorFrameworkFactory.builder().connectString(zkhost) .sessionTimeoutMs(sessionTimeout) .connectionTimeoutMs(connTimeout) .canBeReadOnly(false) .retryPolicy(retryPolicy) //会在路径前面补齐 /zkconfig/node ----> /nameSpace/zkconfig/node .namespace(nameSpace) .defaultData(null).build(); client.getConnectionStateListenable().addListener(new SessionConnectionStateListener()); client.start(); return client; } /** * 判断节点是否存在 * @param path * @return */ public static boolean checkExist(String path) { try { if (client.checkExists().forPath(path) == null) { return false; } return true; } catch (Exception e) { log.error("checkExist error! path: " + path, e); } return false; } /** * 判断节点是否存在并监听节点 * @param path * @param watcher * @return */ public static boolean checkExist(String path,Watcher watcher) { try { if (client.checkExists().usingWatcher(watcher).forPath(path) == null) { return false; } return true; } catch (Exception e) { log.error("checkExist error! path: " + path, e); } return false; } /** * 获取存在的节点数据并监听节点变更 * @param path * @param watcher * @return */ public static String getData(String path, Watcher watcher) { byte[] data = null; String res = null; try { data = (byte[]) ((BackgroundPathable) client.getData().usingWatcher(watcher)).forPath(path); res = new String(data, "utf-8"); } catch (Exception e) { log.error("get data error! path: " + path, e); } return res; } /** * 获取节点数据 * @param path * @return */ public static String getData(String path) { byte[] data = null; String res = null; try { data = (byte[]) client.getData().forPath(path); res = new String(data, "utf-8"); } catch (Exception e) { log.error("get data error! path: " + path, e); } return res; } /* 分布式队列 public static SimpleDistributedQueue createDisQueue(CuratorFramework client, String taskName, String name) { SimpleDistributedQueue queue = new SimpleDistributedQueue(client, ROOT_TASK + "/" + taskName + "/" + name); return queue; } */ /** * 创建持久节点 * @param path * @return */ public static boolean create(String path) { return create(path, ""); } /** * 创建持久节点和数据 * @param path * @param data * @return */ public static boolean create(String path, String data) { try { ((BackgroundPathAndBytesable) ((ACLBackgroundPathAndBytesable) client.create().creatingParentsIfNeeded() .withMode(CreateMode.PERSISTENT)). withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE)) .forPath(path, data.getBytes("utf-8")); return true; } catch (Exception e) { log.error("创建Zookeeper节点出现异常,nodePath:{0}", path, e); } return false; } /** * 增加节点 * @param path * @param childNode * @return */ public static boolean addNode(String path, String childNode) { return !checkExist(path + "/" + childNode) ? create( path + "/" + childNode) : true; } /** * 增加节点 * @param path * @param childNode * @param data * @return */ public static boolean addNode(String path, String childNode, String data) { if (data == null) { data = ""; } return !checkExist( path + "/" + childNode) ? create( path + "/" + childNode, data) : true; } /** * 删除某个子节点 * @param path * @param childNode * @return * @throws Exception */ public static boolean deleteNode(String path, String childNode) { return checkExist( path + "/" + childNode) ? deleteChildrenIfNeeded( path + "/" + childNode) : true; } /** * 级联删除某个Zookeeper节点及其子节点 * @param path * @return * @throws Exception */ public static boolean deleteChildrenIfNeeded(String path) { try { client.delete().deletingChildrenIfNeeded().forPath(path); return true; } catch (Exception e) { log.error("删除Zookeeper节点出现异常,nodePath:{}", path, e); } return false; } /** * 新增持久节点或者更新节点数据 * @param path * @param data * @throws Exception */ public static void createOrUpdateNode(String path, String data) { try { if (!checkExist(path)) { ((BackgroundPathAndBytesable)((ACLBackgroundPathAndBytesable)client.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT)).withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE)).forPath(path, data.getBytes("utf-8")); } else { client.setData().forPath(path, data.getBytes("utf-8")); } } catch (Exception e) { log.error("创建或更新Zookeeper节点出现异常,nodePath:{}", path, e); } } /** * 更新节点数据 * @param path * @param data * @throws Exception */ public static void updateNodeData(String path, String data) { try { client.setData().forPath(path, data.getBytes("utf-8")); } catch (Exception e) { log.error("更新Zookeeper节点出现异常,nodePath:{}", path, e); } } /** * 创建永久Zookeeper节点 * @param nodePath 节点路径（如果父节点不存在则会自动创建父节点），如：/curator * @param nodeValue 节点数据 * @return java.lang.String 返回创建成功的节点路径 */ public static String createPersistentNode(String nodePath, String nodeValue){ try { return client.create().creatingParentsIfNeeded() .forPath(nodePath,nodeValue.getBytes("utf-8")); } catch (Exception e) { log.error("创建永久Zookeeper节点失败,nodePath:{},nodeValue:{}",nodePath,nodeValue,e); } return null; } /** * 创建永久有序Zookeeper节点 * @param nodePath 节点路径（如果父节点不存在则会自动创建父节点），如：/curator * @param nodeValue 节点数据 * @return java.lang.String 返回创建成功的节点路径 */ public static String createSequentialPersistentNode(String nodePath, String nodeValue){ try { return client.create().creatingParentsIfNeeded() .withMode(CreateMode.PERSISTENT_SEQUENTIAL) .forPath(nodePath,nodeValue.getBytes("utf-8")); } catch (Exception e) { log.error("创建永久有序Zookeeper节点失败,nodePath:{},nodeValue:{}",nodePath,nodeValue,e); } return null; } /** * 创建临时Zookeeper节点 * @param nodePath 节点路径（如果父节点不存在则会自动创建父节点），如：/curator * @param nodeValue 节点数据 * @return java.lang.String 返回创建成功的节点路径 */ public static String createEphemeralNode(String nodePath, String nodeValue){ try { return client.create().creatingParentsIfNeeded() .withMode(CreateMode.EPHEMERAL) .forPath(nodePath,nodeValue.getBytes("utf-8")); } catch (Exception e) { log.error("创建临时Zookeeper节点失败,nodePath:{},nodeValue:{}",nodePath,nodeValue,e); } return null; } /** * 创建临时有序Zookeeper节点 * @param nodePath 节点路径（如果父节点不存在则会自动创建父节点），如：/curator * @param nodeValue 节点数据 * @return java.lang.String 返回创建成功的节点路径 */ public static String createSequentialEphemeralNode(String nodePath, String nodeValue){ try { return client.create().creatingParentsIfNeeded() .withMode(CreateMode.EPHEMERAL_SEQUENTIAL) .forPath(nodePath,nodeValue.getBytes("utf-8")); } catch (Exception e) { log.error("创建临时有序Zookeeper节点失败,nodePath:{},nodeValue:{}",nodePath,nodeValue,e); } return null; } /** * 获取某个Zookeeper节点的所有子节点 * @param nodePath 节点路径 * @return java.util.List返回所有子节点的节点名 */ public static List getChildren(String nodePath){ try { return client.getChildren().forPath(nodePath); } catch (Exception e) { log.error("获取某个Zookeeper节点的所有子节点出现异常,nodePath:{}",nodePath,e); } return null; } /** * 注册节点监听器 * NodeCache: 对一个节点进行监听，监听事件包括指定路径的增删改操作 * @param nodePath 节点路径 * @param listener 监控事件的回调接口 * @return void */ public static NodeCache registerNodeCacheListener(String nodePath,AbstractNodeCacheListener listener){ try { //1. 创建一个NodeCache NodeCache nodeCache = new NodeCache(client, nodePath); //2. 缓存NodeCache listener.setNodeCache(nodeCache); //3. 添加节点监听器 nodeCache.getListenable().addListener(listener); //4. 启动监听器 nodeCache.start(); //5. 返回NodeCache return nodeCache; } catch (Exception e) { log.error("注册节点监听器出现异常,nodePath:{}",nodePath,e); } return null; } /** * 注册目录中子目录监听器 * PathChildrenCache：对指定路径节点的一级子目录监听，不对该节点的操作监听，对其子目录的增删改操作监听 * 备注: 当节点存在时，添加监听事件后会触发 NODE_ADDED * @param nodePath 节点路径 * @param listener 监控事件的回调接口 * @return org.apache.curator.framework.recipes.cache.PathChildrenCache */ public static PathChildrenCache registerPathChildListener(String nodePath, PathChildrenCacheListener listener){ try { //1. 创建一个PathChildrenCache PathChildrenCache pathChildrenCache = new PathChildrenCache(client, nodePath, true); //2. 添加目录监听器 pathChildrenCache.getListenable().addListener(listener); //3. 启动监听器 pathChildrenCache.start(PathChildrenCache.StartMode.BUILD_INITIAL_CACHE); //4. 返回PathChildrenCache return pathChildrenCache; } catch (Exception e) { log.error("注册子目录监听器出现异常,nodePath:{}",nodePath,e); } return null; } /** * 注册目录监听器 * TreeCache：综合NodeCache和PathChildrenCahce的特性，可以对整个目录进行监听，同时还可以设置监听深度 * 备注: 当节点存在时，添加监听事件后会触发 NODE_ADDED * @param nodePath 节点路径 * @param maxDepth 自定义监控深度 * @param listener 监控事件的回调接口 * @return org.apache.curator.framework.recipes.cache.TreeCache */ public static TreeCache registerTreeCacheListener(String nodePath, int maxDepth, TreeCacheListener listener){ try { //1. 创建一个TreeCache TreeCache treeCache = TreeCache.newBuilder(client, nodePath) .setCacheData(true) .setMaxDepth(maxDepth) .build(); //2. 添加目录监听器 treeCache.getListenable().addListener(listener); //3. 启动监听器 treeCache.start(); //4. 返回TreeCache return treeCache; } catch (Exception e) { log.error("注册目录监听器出现异常,nodePath:{},maxDepth:{}",nodePath,e); } return null; } }
4 zkconfig.properties
DEV_ZK_SERVER=127.0.0.1 PRD_ZK_SERVER=127.0.0.1
5 测试代码
public static void testCreate(){
ZkUtil.initialize();
String parent = "/zkconfig";
String child = "chynode";
String path = parent + "/" + child;
NodeWatcher nodeWatcher = new NodeWatcher(ZkUtil.client, path);
//开启监听
ZkUtil.checkExist("/zkconfig/chynode", nodeWatcher);
//如果不存在节点增加节点
try {
if (!ZkUtil.checkExist(path)) {
ZkUtil.addNode(parent, child, "chy");
}
} catch (Exception e) {
e.printStackTrace();
}
//如果存在节点获取节点信息
if (ZkUtil.checkExist(path)) {
log.info("{}:{}", path, ZkUtil.getData("/zkconfig/chynode"));
}
}
public static void testDelete(){
ZkUtil.initialize();
String parent = "/zkconfig";
String child = "chynode";
String path = parent + "/" + child;
NodeWatcher nodeWatcher = new NodeWatcher(ZkUtil.client, path);
//如果不存在节点增加节点
try {
if (!ZkUtil.checkExist(path)) {
ZkUtil.addNode(parent, child, "chy");
ZkUtil.addNode(parent, "chytemp", "chy");
}
} catch (Exception e) {
e.printStackTrace();
}
List paths = ZkUtil.getChildren(parent);
log.info("paths:{}", JSONObject.toJSONString(paths));
//删除子节点
ZkUtil.deleteNode(parent, child);
paths = ZkUtil.getChildren(parent);
log.info("paths:{}", JSONObject.toJSONString(paths));
//删除当前节点以及子节点
ZkUtil.deleteChildrenIfNeeded(parent);
paths = ZkUtil.getChildren(parent);
log.info("paths:{}", JSONObject.toJSONString(paths));
}
public static void testSequentialEphemeralNode(){
ZkUtil.initialize();
String parent = "/zkconfig";
String child = "chynode";
String path = parent + "/" + child;
ZkUtil.deleteChildrenIfNeeded(parent);
log.info(ZkUtil.createSequentialEphemeralNode(path,"001"));
log.info(ZkUtil.createSequentialEphemeralNode(path,"002"));
log.info(ZkUtil.createSequentialEphemeralNode(path,"003"));
List paths = ZkUtil.getChildren(parent);
log.info("paths:{}", JSONObject.toJSONString(paths));
}
public static void testSequentialPersistentNode(){
ZkUtil.initialize();
String parent = "/zkconfig";
String child = "chynode";
String path = parent + "/" + child;
ZkUtil.deleteChildrenIfNeeded(parent);
log.info(ZkUtil.createSequentialPersistentNode(path,"001"));
log.info(ZkUtil.createSequentialPersistentNode(path,"002"));
log.info(ZkUtil.createSequentialPersistentNode(path,"003"));
List paths = ZkUtil.getChildren(parent);
log.info("paths:{}", JSONObject.toJSONString(paths));
}
public static void testPersistentNode(){
ZkUtil.initialize();
String parent = "/zkconfig";
String child = "chynode";
String path = parent + "/" + child;
ZkUtil.deleteChildrenIfNeeded(parent);
log.info(ZkUtil.createEphemeralNode(path,"001"));
List paths = ZkUtil.getChildren(parent);
log.info("paths:{}", JSONObject.toJSONString(paths));
}