Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.buaa.cfs.utils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.IOException; import java.io.InputStream; import java.util.Properties; /** * This class returns build information about Hadoop components. */ public class VersionInfo { private static final Log LOG = LogFactory.getLog(VersionInfo.class); private Properties info; protected VersionInfo(String component) { info = new Properties(); String versionInfoFile = component + "-version-info.properties"; InputStream is = null; try { is = Thread.currentThread().getContextClassLoader().getResourceAsStream(versionInfoFile); if (is == null) { throw new IOException("Resource not found"); } info.load(is); } catch (IOException ex) { LogFactory.getLog(getClass()).warn("Could not read '" + versionInfoFile + "', " + ex.toString(), ex); } finally { IOUtils.closeStream(is); } } protected String _getVersion() { return info.getProperty("version", "Unknown"); } protected String _getRevision() { return info.getProperty("revision", "Unknown"); } protected String _getBranch() { return info.getProperty("branch", "Unknown"); } protected String _getDate() { return info.getProperty("date", "Unknown"); } protected String _getUser() { return info.getProperty("user", "Unknown"); } protected String _getUrl() { return info.getProperty("url", "Unknown"); } protected String _getSrcChecksum() { return info.getProperty("srcChecksum", "Unknown"); } protected String _getBuildVersion() { return getVersion() + " from " + _getRevision() + " by " + _getUser() + " source checksum " + _getSrcChecksum(); } protected String _getProtocVersion() { return info.getProperty("protocVersion", "Unknown"); } private static VersionInfo COMMON_VERSION_INFO = new VersionInfo("common"); /** * Get the Hadoop version. * @return the Hadoop version string, eg. "0.6.3-dev" */ public static String getVersion() { return COMMON_VERSION_INFO._getVersion(); } /** * Get the subversion revision number for the root directory * @return the revision number, eg. "451451" */ public static String getRevision() { return COMMON_VERSION_INFO._getRevision(); } /** * Get the branch on which this originated. * @return The branch name, e.g. "trunk" or "branches/branch-0.20" */ public static String getBranch() { return COMMON_VERSION_INFO._getBranch(); } /** * The date that Hadoop was compiled. * @return the compilation date in unix date format */ public static String getDate() { return COMMON_VERSION_INFO._getDate(); } /** * The user that compiled Hadoop. * @return the username of the user */ public static String getUser() { return COMMON_VERSION_INFO._getUser(); } /** * Get the subversion URL for the root Hadoop directory. */ public static String getUrl() { return COMMON_VERSION_INFO._getUrl(); } /** * Get the checksum of the source files from which Hadoop was * built. **/ public static String getSrcChecksum() { return COMMON_VERSION_INFO._getSrcChecksum(); } /** * Returns the buildVersion which includes version, * revision, user and date. */ public static String getBuildVersion() { return COMMON_VERSION_INFO._getBuildVersion(); } /** * Returns the protoc version used for the build. */ public static String getProtocVersion() { return COMMON_VERSION_INFO._getProtocVersion(); } public static void main(String[] args) { LOG.debug("version: " + getVersion()); System.out.println("Hadoop " + getVersion()); System.out.println("Subversion " + getUrl() + " -r " + getRevision()); System.out.println("Compiled by " + getUser() + " on " + getDate()); System.out.println("Compiled with protoc " + getProtocVersion()); System.out.println("From source with checksum " + getSrcChecksum()); System.out.println("This command was run using " + ClassUtil.findContainingJar(VersionInfo.class)); } }