连接Zookeeper操作
public class ZKConnector implements Watcher{ private static final Logger logger =LoggerFactory.getLogger(ZKConnector.class); private CountDownLatch connectedSemaphore = new CountDownLatch(1); private ZooKeeper zk =null; /** * 释放zookeeper连接 */ public void releaseConnection() { if (this.zk!=null) { try { this.zk.close(); } catch ( InterruptedException e ) { e.printStackTrace(); } } } /** * 创建zookeeper的连接 * @param connectString zookeeper服务器地址列表 * @param sessionTimeout Session超时时间 */ public void createConnection(String connectString, int sessionTimeout) { //先释放zookeeper连接 this.releaseConnection(); try { zk = new ZooKeeper( connectString, sessionTimeout, this); connectedSemaphore.await(); } catch ( InterruptedException e ) { logger.info( "连接创建失败,发生 InterruptedException"); e.printStackTrace(); } catch (IOException e ) { logger.info( "连接创建失败,发生 IOException" ); e.printStackTrace(); } } /** * 检查Znode是否为空 */ public boolean check(String zNode){ try { return this.zk.exists(zNode, false).getDataLength()>0; } catch (KeeperException | InterruptedException e) { e.printStackTrace(); } return false; } /** * 检查zNode是否存在 * 不为空 返回true * 为空,则返回false */ public boolean exist(String zNode){ try { Stat stat =this.zk.exists(zNode, false); return stat==null?false:true; } catch (KeeperException | InterruptedException e) { e.printStackTrace(); } return true; } /** * 读取zNode的数据 */ public String readData(String path){ try { if(this.zk.exists(path, false) == null){ return ""; } return new String( this.zk.getData(path, false, null)); } catch ( KeeperException e){ logger.info("读取数据失败,发生KeeperException,path: " + path); e.printStackTrace(); return ""; } catch ( InterruptedException e){ logger.info("读取数据失败,发生 InterruptedException,path: " + path); e.printStackTrace(); return ""; } } /** * 更新zNode的数据 */ public boolean writeData(String path,String data){ try { if(this.zk.exists(path, false) == null){ return createPersistNode(path,data); }else{ deleteNode(path); createPersistNode(path,data); } } catch ( KeeperException e ) { logger.info( "更新数据失败,发生KeeperException,path: " + path ); e.printStackTrace(); } catch ( InterruptedException e ) { logger.info( "更新数据失败,发生 InterruptedException,path: " + path ); e.printStackTrace(); } return false; } /** * 获取子节点数据 */ public List<String> getChildren(String node){ try { List<String> subNodes = this.zk.getChildren(node, false); return subNodes; } catch (KeeperException | InterruptedException e) { e.printStackTrace(); } return null; } /** * 创建持久化节点 * @param path 节点path * @param data 初始数据内容 * @return */ public boolean createPersistNode(String path, String data) { try { String createpath =this.zk.create(path,data.getBytes(),Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT ); logger.info("节点创建成功, Path: " + createpath + ", content: " + data ); return true; } catch ( KeeperException e ) { logger.info( "节点创建失败,发生KeeperException" ); e.printStackTrace(); } catch ( InterruptedException e ) { logger.info( "节点创建失败,发生 InterruptedException" ); e.printStackTrace(); } return false; } /** * 创建短暂序列化节点 * @param path 节点path * @param data 初始数据内容 * @param needWatch * @return */ public String createEsquentialNode(String path, String data) { String esquentialNode = null; try { esquentialNode =this.zk.create(path,data.getBytes(),Ids.OPEN_ACL_UNSAFE,CreateMode.EPHEMERAL_SEQUENTIAL); logger.info("节点创建成功, Path: " + esquentialNode + ", content: " + data ); return esquentialNode; } catch ( KeeperException e ) { logger.info( "节点创建失败,发生KeeperException" ); e.printStackTrace(); } catch ( InterruptedException e ) { logger.info( "节点创建失败,发生 InterruptedException" ); e.printStackTrace(); } return null; } /** * 删除节点 */ public void deleteNode(String path) { try { if(this.zk.exists(path, false) == null){ logger.info("该节点不存在!不做任何操作" ); }else{ this.zk.delete(path, -1); logger.info("删除节点成功,path:"+ path); } } catch ( KeeperException e ) { logger.info("删除节点失败,发生KeeperException,path: " + path); e.printStackTrace(); } catch ( InterruptedException e ) { logger.info("删除节点失败,发生 InterruptedException,path: " + path); e.printStackTrace(); } } @Override public void process(WatchedEvent event) { logger.info( "收到事件通知:" + event.getState() +"\n" ); if ( KeeperState.SyncConnected == event.getState() ) { connectedSemaphore.countDown(); } } }