Java tutorial
/** * Copyright 2011 Rapleaf * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.rapleaf.hank; import java.io.BufferedReader; import java.io.File; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.Reader; import java.net.BindException; import java.net.InetSocketAddress; import java.net.Socket; import java.util.List; import java.util.concurrent.atomic.AtomicBoolean; import org.apache.commons.io.FileUtils; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Level; import org.apache.log4j.Logger; import org.apache.zookeeper.CreateMode; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.Watcher.Event.KeeperState; import org.apache.zookeeper.ZooDefs.Ids; import org.apache.zookeeper.ZooKeeper.States; import org.apache.zookeeper.server.NIOServerCnxn; import org.apache.zookeeper.server.ZooKeeperServer; import org.apache.zookeeper.server.NIOServerCnxn.Factory; import com.rapleaf.hank.zookeeper.ZooKeeperPlus; public class ZkTestCase extends BaseTestCase { private static final Logger LOG = Logger.getLogger(ZkTestCase.class); private static final int TICK_TIME = 2000; private static final int CONNECTION_TIMEOUT = 30000; protected static final int WAIT_TIME = 10000; private final static String zkDir = System.getProperty("zk_dir", "/tmp/zk_in_tests"); private static Factory standaloneServerFactory; private static ZooKeeperServer server; private static int zkClientPort; private final String zkRoot; private ZooKeeperPlus zk; public ZkTestCase() { super(); zkRoot = "/" + getClass().getSimpleName(); } public static void setupZkServer() throws Exception { if (server == null) { LOG.debug("deleting zk data dir (" + zkDir + ")"); File zkDirFile = new File(zkDir); FileUtils.deleteDirectory(zkDirFile); zkDirFile.mkdirs(); server = new ZooKeeperServer(zkDirFile, zkDirFile, TICK_TIME); int clientPort = 2000; while (true) { LOG.debug("Trying to bind server to port " + clientPort); try { standaloneServerFactory = new NIOServerCnxn.Factory(new InetSocketAddress(clientPort)); } catch (BindException e) { LOG.trace("Failed binding ZK Server to client port: " + clientPort); //this port is already in use. try to use another clientPort++; continue; } LOG.debug("Succeeded in binding ZK Server to client port " + clientPort); break; } standaloneServerFactory.startup(server); if (!waitForServerUp(clientPort, CONNECTION_TIMEOUT)) { throw new IOException("Waiting for startup of standalone server"); } zkClientPort = clientPort; } } @Override protected void setUp() throws Exception { super.setUp(); Logger.getLogger("org.apache.zookeeper").setLevel(Level.WARN); setupZkServer(); final Object lock = new Object(); final AtomicBoolean connected = new AtomicBoolean(false); zk = new ZooKeeperPlus("127.0.0.1:" + zkClientPort, 1000000, new Watcher() { @Override public void process(WatchedEvent event) { switch (event.getType()) { case None: if (event.getState() == KeeperState.SyncConnected) { connected.set(true); synchronized (lock) { lock.notifyAll(); } } } LOG.debug(event.toString()); } }); synchronized (lock) { lock.wait(2000); } if (!connected.get()) { fail("timed out waiting for the zk client connection to come online!"); } LOG.debug("session timeout: " + zk.getSessionTimeout()); zk.deleteNodeRecursively(zkRoot); createNodeRecursively(zkRoot); } private static boolean waitForServerUp(int port, long timeout) { long start = System.currentTimeMillis(); while (true) { try { Socket sock = new Socket("localhost", port); BufferedReader reader = null; try { OutputStream outstream = sock.getOutputStream(); outstream.write("stat".getBytes()); outstream.flush(); Reader isr = new InputStreamReader(sock.getInputStream()); reader = new BufferedReader(isr); String line = reader.readLine(); if (line != null && line.startsWith("Zookeeper version:")) { return true; } } finally { sock.close(); if (reader != null) { reader.close(); } } } catch (IOException e) { // ignore as this is expected LOG.info("server localhost:" + port + " not up " + e); } if (System.currentTimeMillis() > start + timeout) { break; } try { Thread.sleep(250); } catch (InterruptedException e) { // ignore } } return false; } public String getRoot() { return zkRoot; } public ZooKeeperPlus getZk() { return zk; } @Override protected void tearDown() throws Exception { LOG.debug("teardown called"); super.tearDown(); shutdownZk(); } public void shutdownZk() throws Exception { if (zk != null && zk.getState() == States.CONNECTED) { zk.close(); } zk = null; } public int getZkClientPort() { return zkClientPort; } public String getZkConnectString() { return "localhost:" + zkClientPort; } public void dumpZk() throws Exception { dumpZk("", "", 0); } private void dumpZk(String parentPath, String nodeName, int depth) throws Exception { System.err.print(StringUtils.repeat(" ", depth)); System.err.print("/" + nodeName); String nodePath = parentPath + "/" + nodeName; nodePath = nodePath.replace("//", "/"); byte[] data = zk.getData(nodePath, false, null); if (data == null) { System.err.print(" -> null"); } else { System.err.print(" -> [bytes]"); } System.err.println(); List<String> children = zk.getChildren(nodePath, false); for (String child : children) { dumpZk(nodePath, child, depth + 1); } } protected void createNodeRecursively(String path) throws InterruptedException, Exception { String[] toks = path.split("/"); String newPath = "/"; for (int i = 0; i < toks.length; i++) { newPath += toks[i]; if (zk.exists(newPath, false) == null) { zk.create(newPath, null, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); } if (i != 0) { newPath += "/"; } } } protected void create(String path) throws Exception { create(path, (byte[]) null); } protected void create(String path, String data) throws Exception { create(path, data.getBytes()); } protected void create(String path, byte[] data) throws Exception { getZk().create(path, data, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); } }