Java tutorial
/* * Copyright 2014, Stratio. * * 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.stratio.deep.cassandra.embedded; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URL; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.RejectedExecutionException; import java.util.concurrent.TimeUnit; import org.apache.cassandra.config.DatabaseDescriptor; import org.apache.cassandra.db.commitlog.CommitLog; import org.apache.cassandra.exceptions.ConfigurationException; import org.apache.cassandra.io.util.FileUtils; import org.apache.cassandra.service.CassandraDaemon; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import org.apache.thrift.transport.TTransportException; import com.datastax.driver.core.Cluster; import com.datastax.driver.core.Session; import com.google.common.base.Charsets; import com.google.common.io.Files; import com.google.common.io.Resources; import com.stratio.deep.commons.utils.Constants; /** * Embedded Cassandra Server helper class. */ public class CassandraServer { private class CassandraRunner implements Runnable { @Override public void run() { cassandraDaemon = new CassandraDaemon(); cassandraDaemon.activate(); cassandraDaemon.start(); } } public static final int CASSANDRA_THRIFT_PORT = 9360; public static final int CASSANDRA_CQL_PORT = 9242; private static final Logger logger = Logger.getLogger(CassandraServer.class); private static final int WAIT_SECONDS = 4; private static void cleanup() throws IOException { // clean up commitlog String[] directoryNames = { DatabaseDescriptor.getCommitLogLocation(), }; for (String dirName : directoryNames) { File dir = new File(dirName); if (!dir.exists()) { logger.error("No such directory: " + dir.getAbsolutePath()); throw new RuntimeException("No such directory: " + dir.getAbsolutePath()); } FileUtils.deleteRecursive(dir); } // clean up data directory which are stored as data directory/table/data // files for (String dirName : DatabaseDescriptor.getAllDataFileLocations()) { File dir = new File(dirName); if (!dir.exists()) { logger.error("No such directory: " + dir.getAbsolutePath()); throw new RuntimeException("No such directory: " + dir.getAbsolutePath()); } FileUtils.deleteRecursive(dir); } } private static void cleanupAndLeaveDirs() throws IOException { mkdirs(); cleanup(); mkdirs(); CommitLog.instance.resetUnsafe(); // cleanup screws w/ CommitLog, this // brings it back to safe state } /** * Copies a resource from within the jar to a directory. * * @param resource * @param directory * @throws IOException */ private static void copy(String resource, String directory) throws IOException { mkdir(directory); InputStream is = CassandraServer.class.getResourceAsStream(resource); String fileName = resource.substring(resource.lastIndexOf("/") + 1); File file = new File(directory + System.getProperty("file.separator") + fileName); OutputStream out = new FileOutputStream(file); byte buf[] = new byte[1024]; int len; while ((len = is.read(buf)) > 0) { out.write(buf, 0, len); } out.close(); is.close(); } /** * Creates a directory * * @param dir * @throws IOException */ private static void mkdir(String dir) throws IOException { FileUtils.createDirectory(dir); } private static void mkdirs() { DatabaseDescriptor.createAllDirectories(); } private final String yamlFilePath; private CassandraDaemon cassandraDaemon; private String[] startupCommands; static ExecutorService executor = Executors.newSingleThreadExecutor(); public CassandraServer() { this("/cassandra.yaml"); } public CassandraServer(String yamlFile) { this.yamlFilePath = yamlFile; } public String[] getStartupCommands() { return startupCommands; } private void initKeySpace() { if (startupCommands == null || startupCommands.length == 0) { return; } Cluster cluster = Cluster.builder().withPort(CASSANDRA_CQL_PORT) .addContactPoint(Constants.DEFAULT_CASSANDRA_HOST).build(); try (Session session = cluster.connect()) { for (String command : startupCommands) { try { if (StringUtils.isNotEmpty(command)) { session.execute(command); } } catch (Exception e) { e.printStackTrace(); } } } } public void setStartupCommands(String[] startupCommands) { this.startupCommands = startupCommands; } public void shutdown() throws IOException { executor.shutdown(); executor.shutdownNow(); } /** * Set embedded cassandra up and spawn it in a new thread. * * @throws TTransportException * @throws IOException * @throws InterruptedException */ public void start() throws IOException, InterruptedException, ConfigurationException { File dir = Files.createTempDir(); String dirPath = dir.getAbsolutePath(); logger.info("Storing Cassandra files in " + dirPath); URL url = Resources.getResource("cassandra.yaml"); String yaml = Resources.toString(url, Charsets.UTF_8); yaml = yaml.replaceAll("REPLACEDIR", dirPath); String yamlPath = dirPath + File.separatorChar + "cassandra.yaml"; org.apache.commons.io.FileUtils.writeStringToFile(new File(yamlPath), yaml); // make a tmp dir and copy cassandra.yaml and log4j.properties to it try { copy("/log4j.properties", dir.getAbsolutePath()); } catch (Exception e1) { logger.error("Cannot copy log4j.properties"); } System.setProperty("cassandra.config", "file:" + dirPath + yamlFilePath); System.setProperty("log4j.configuration", "file:" + dirPath + "/log4j.properties"); System.setProperty("cassandra-foreground", "true"); System.setProperty("cassandra.skip_wait_for_gossip_to_settle", "0"); cleanupAndLeaveDirs(); try { executor.execute(new CassandraRunner()); } catch (RejectedExecutionException e) { logger.error(e); return; } try { TimeUnit.SECONDS.sleep(WAIT_SECONDS); } catch (InterruptedException e) { logger.error(e); throw new AssertionError(e); } initKeySpace(); } }