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 org.apache.commons.lang; import java.io.File; /** * <p>Helpers for <code>java.lang.System</code>.</p> * * <p>If a system property cannot be read due to security restrictions, * the corresponding field in this class will be set to <code>null</code> * and a message will be written to <code>System.err</code>.</p> * * @author Based on code from Avalon Excalibur * @author Based on code from Lucene * @author Stephen Colebourne * @author <a href="mailto:sdowney@panix.com">Steve Downey</a> * @author Gary Gregory * @author Michael Becke * @author Tetsuya Kaneuchi * @author Rafal Krupinski * @author Jason Gritman * @since 1.0 * @version $Id: SystemUtils.java 437554 2006-08-28 06:21:41Z bayard $ */ public class SystemUtils { /** * The prefix String for all Windows OS. */ private static final String OS_NAME_WINDOWS_PREFIX = "Windows"; // System property constants //----------------------------------------------------------------------- // These MUST be declared first. Other constants depend on this. /** * The System property key for the user home directory. */ private static final String USER_HOME_KEY = "user.home"; /** * The System property key for the user directory. */ private static final String USER_DIR_KEY = "user.dir"; /** * The System property key for the Java IO temporary directory. */ private static final String JAVA_IO_TMPDIR_KEY = "java.io.tmpdir"; /** * The System property key for the Java home directory. */ private static final String JAVA_HOME_KEY = "java.home"; /** * <p>The <code>awt.toolkit</code> System Property.</p> * <p>Holds a class name, on Windows XP this is <code>sun.awt.windows.WToolkit</code>.</p> * <p><b>On platforms without a GUI, this value is <code>null</code>.</b></p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.1 */ public static final String AWT_TOOLKIT = getSystemProperty("awt.toolkit"); /** * <p>The <code>file.encoding</code> System Property.</p> * <p>File encoding, such as <code>Cp1252</code>.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.0 * @since Java 1.2 */ public static final String FILE_ENCODING = getSystemProperty("file.encoding"); /** * <p>The <code>file.separator</code> System Property. * File separator (<code>"/"</code> on UNIX).</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String FILE_SEPARATOR = getSystemProperty("file.separator"); /** * <p>The <code>java.awt.fonts</code> System Property.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.1 */ public static final String JAVA_AWT_FONTS = getSystemProperty("java.awt.fonts"); /** * <p>The <code>java.awt.graphicsenv</code> System Property.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.1 */ public static final String JAVA_AWT_GRAPHICSENV = getSystemProperty("java.awt.graphicsenv"); /** * <p> * The <code>java.awt.headless</code> System Property. * The value of this property is the String <code>"true"</code> or <code>"false"</code>. * </p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @see #isJavaAwtHeadless() * @since 2.1 * @since Java 1.4 */ public static final String JAVA_AWT_HEADLESS = getSystemProperty("java.awt.headless"); /** * <p>The <code>java.awt.printerjob</code> System Property.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.1 */ public static final String JAVA_AWT_PRINTERJOB = getSystemProperty("java.awt.printerjob"); /** * <p>The <code>java.class.path</code> System Property. Java class path.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String JAVA_CLASS_PATH = getSystemProperty("java.class.path"); /** * <p>The <code>java.class.version</code> System Property. * Java class format version number.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String JAVA_CLASS_VERSION = getSystemProperty("java.class.version"); /** * <p>The <code>java.compiler</code> System Property. Name of JIT compiler to use. * First in JDK version 1.2. Not used in Sun JDKs after 1.2.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2. Not used in Sun versions after 1.2. */ public static final String JAVA_COMPILER = getSystemProperty("java.compiler"); /** * <p>The <code>java.endorsed.dirs</code> System Property. Path of endorsed directory * or directories.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.4 */ public static final String JAVA_ENDORSED_DIRS = getSystemProperty("java.endorsed.dirs"); /** * <p>The <code>java.ext.dirs</code> System Property. Path of extension directory * or directories.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.3 */ public static final String JAVA_EXT_DIRS = getSystemProperty("java.ext.dirs"); /** * <p>The <code>java.home</code> System Property. Java installation directory.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String JAVA_HOME = getSystemProperty(JAVA_HOME_KEY); /** * <p>The <code>java.io.tmpdir</code> System Property. Default temp file path.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_IO_TMPDIR = getSystemProperty(JAVA_IO_TMPDIR_KEY); /** * <p>The <code>java.library.path</code> System Property. List of paths to search * when loading libraries.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_LIBRARY_PATH = getSystemProperty("java.library.path"); /** * <p>The <code>java.runtime.name</code> System Property. Java Runtime Environment * name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.0 * @since Java 1.3 */ public static final String JAVA_RUNTIME_NAME = getSystemProperty("java.runtime.name"); /** * <p>The <code>java.runtime.version</code> System Property. Java Runtime Environment * version.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.0 * @since Java 1.3 */ public static final String JAVA_RUNTIME_VERSION = getSystemProperty("java.runtime.version"); /** * <p>The <code>java.specification.name</code> System Property. Java Runtime Environment * specification name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_SPECIFICATION_NAME = getSystemProperty("java.specification.name"); /** * <p>The <code>java.specification.vendor</code> System Property. Java Runtime Environment * specification vendor.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_SPECIFICATION_VENDOR = getSystemProperty("java.specification.vendor"); /** * <p>The <code>java.specification.version</code> System Property. Java Runtime Environment * specification version.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.3 */ public static final String JAVA_SPECIFICATION_VERSION = getSystemProperty("java.specification.version"); /** * <p>The <code>java.util.prefs.PreferencesFactory</code> System Property. A class name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.1 * @since Java 1.4 */ public static final String JAVA_UTIL_PREFS_PREFERENCES_FACTORY = getSystemProperty( "java.util.prefs.PreferencesFactory"); /** * <p>The <code>java.vendor</code> System Property. Java vendor-specific string.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String JAVA_VENDOR = getSystemProperty("java.vendor"); /** * <p>The <code>java.vendor.url</code> System Property. Java vendor URL.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String JAVA_VENDOR_URL = getSystemProperty("java.vendor.url"); /** * <p>The <code>java.version</code> System Property. Java version number.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String JAVA_VERSION = getSystemProperty("java.version"); /** * <p>The <code>java.vm.info</code> System Property. Java Virtual Machine implementation * info.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.0 * @since Java 1.2 */ public static final String JAVA_VM_INFO = getSystemProperty("java.vm.info"); /** * <p>The <code>java.vm.name</code> System Property. Java Virtual Machine implementation * name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_VM_NAME = getSystemProperty("java.vm.name"); /** * <p>The <code>java.vm.specification.name</code> System Property. Java Virtual Machine * specification name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_VM_SPECIFICATION_NAME = getSystemProperty("java.vm.specification.name"); /** * <p>The <code>java.vm.specification.vendor</code> System Property. Java Virtual * Machine specification vendor.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_VM_SPECIFICATION_VENDOR = getSystemProperty("java.vm.specification.vendor"); /** * <p>The <code>java.vm.specification.version</code> System Property. Java Virtual Machine * specification version.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_VM_SPECIFICATION_VERSION = getSystemProperty("java.vm.specification.version"); /** * <p>The <code>java.vm.vendor</code> System Property. Java Virtual Machine implementation * vendor.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_VM_VENDOR = getSystemProperty("java.vm.vendor"); /** * <p>The <code>java.vm.version</code> System Property. Java Virtual Machine * implementation version.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.2 */ public static final String JAVA_VM_VERSION = getSystemProperty("java.vm.version"); /** * <p>The <code>line.separator</code> System Property. Line separator * (<code>"\n"</code> on UNIX).</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String LINE_SEPARATOR = getSystemProperty("line.separator"); /** * <p>The <code>os.arch</code> System Property. Operating system architecture.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String OS_ARCH = getSystemProperty("os.arch"); /** * <p>The <code>os.name</code> System Property. Operating system name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String OS_NAME = getSystemProperty("os.name"); /** * <p>The <code>os.version</code> System Property. Operating system version.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String OS_VERSION = getSystemProperty("os.version"); /** * <p>The <code>path.separator</code> System Property. Path separator * (<code>":"</code> on UNIX).</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String PATH_SEPARATOR = getSystemProperty("path.separator"); /** * <p>The <code>user.country</code> or <code>user.region</code> System Property. * User's country code, such as <code>GB</code>. First in JDK version 1.2 as * <code>user.region</code>. Renamed to <code>user.country</code> in 1.4</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.0 * @since Java 1.2 */ public static final String USER_COUNTRY = getSystemProperty("user.country") == null ? getSystemProperty("user.region") : getSystemProperty("user.country"); /** * <p>The <code>user.dir</code> System Property. User's current working * directory.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String USER_DIR = getSystemProperty(USER_DIR_KEY); /** * <p>The <code>user.home</code> System Property. User's home directory.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String USER_HOME = getSystemProperty(USER_HOME_KEY); /** * <p>The <code>user.language</code> System Property. User's language code, * such as <code>"en"</code>.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.0 * @since Java 1.2 */ public static final String USER_LANGUAGE = getSystemProperty("user.language"); /** * <p>The <code>user.name</code> System Property. User's account name.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since Java 1.1 */ public static final String USER_NAME = getSystemProperty("user.name"); /** * <p>The <code>user.timezone</code> System Property. * For example: <code>"America/Los_Angeles"</code>.</p> * * <p>Defaults to <code>null</code> if the runtime does not have * security access to read this property or the property does not exist.</p> * * <p> * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} * or {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value * will be out of sync with that System property. * </p> * * @since 2.1 */ public static final String USER_TIMEZONE = getSystemProperty("user.timezone"); // Java version //----------------------------------------------------------------------- // This MUST be declared after those above as it depends on the // values being set up /** * <p>Gets the Java version as a <code>String</code> trimming leading letters.</p> * * <p>The field will return <code>null</code> if {@link #JAVA_VERSION} is <code>null</code>.</p> * * @since 2.1 */ public static final String JAVA_VERSION_TRIMMED = getJavaVersionTrimmed(); // Java version values //----------------------------------------------------------------------- // These MUST be declared after the trim above as they depend on the // value being set up /** * <p>Gets the Java version as a <code>float</code>.</p> * * <p>Example return values:</p> * <ul> * <li><code>1.2f</code> for JDK 1.2 * <li><code>1.31f</code> for JDK 1.3.1 * </ul> * * <p>The field will return zero if {@link #JAVA_VERSION} is <code>null</code>.</p> * * @since 2.0 */ public static final float JAVA_VERSION_FLOAT = getJavaVersionAsFloat(); /** * <p>Gets the Java version as an <code>int</code>.</p> * * <p>Example return values:</p> * <ul> * <li><code>120</code> for JDK 1.2 * <li><code>131</code> for JDK 1.3.1 * </ul> * * <p>The field will return zero if {@link #JAVA_VERSION} is <code>null</code>.</p> * * @since 2.0 */ public static final int JAVA_VERSION_INT = getJavaVersionAsInt(); // Java version checks //----------------------------------------------------------------------- // These MUST be declared after those above as they depend on the // values being set up /** * <p>Is <code>true</code> if this is Java version 1.1 (also 1.1.x versions).</p> * * <p>The field will return <code>false</code> if {@link #JAVA_VERSION} is * <code>null</code>.</p> */ public static final boolean IS_JAVA_1_1 = getJavaVersionMatches("1.1"); /** * <p>Is <code>true</code> if this is Java version 1.2 (also 1.2.x versions).</p> * * <p>The field will return <code>false</code> if {@link #JAVA_VERSION} is * <code>null</code>.</p> */ public static final boolean IS_JAVA_1_2 = getJavaVersionMatches("1.2"); /** * <p>Is <code>true</code> if this is Java version 1.3 (also 1.3.x versions).</p> * * <p>The field will return <code>false</code> if {@link #JAVA_VERSION} is * <code>null</code>.</p> */ public static final boolean IS_JAVA_1_3 = getJavaVersionMatches("1.3"); /** * <p>Is <code>true</code> if this is Java version 1.4 (also 1.4.x versions).</p> * * <p>The field will return <code>false</code> if {@link #JAVA_VERSION} is * <code>null</code>.</p> */ public static final boolean IS_JAVA_1_4 = getJavaVersionMatches("1.4"); /** * <p>Is <code>true</code> if this is Java version 1.5 (also 1.5.x versions).</p> * * <p>The field will return <code>false</code> if {@link #JAVA_VERSION} is * <code>null</code>.</p> */ public static final boolean IS_JAVA_1_5 = getJavaVersionMatches("1.5"); /** * <p>Is <code>true</code> if this is Java version 1.6 (also 1.6.x versions).</p> * * <p>The field will return <code>false</code> if {@link #JAVA_VERSION} is * <code>null</code>.</p> */ public static final boolean IS_JAVA_1_6 = getJavaVersionMatches("1.6"); // Operating system checks //----------------------------------------------------------------------- // These MUST be declared after those above as they depend on the // values being set up // OS names from http://www.vamphq.com/os.html // Selected ones included - please advise commons-dev@jakarta.apache.org // if you want another added or a mistake corrected /** * <p>Is <code>true</code> if this is AIX.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_AIX = getOSMatches("AIX"); /** * <p>Is <code>true</code> if this is HP-UX.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_HP_UX = getOSMatches("HP-UX"); /** * <p>Is <code>true</code> if this is Irix.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_IRIX = getOSMatches("Irix"); /** * <p>Is <code>true</code> if this is Linux.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_LINUX = getOSMatches("Linux") || getOSMatches("LINUX"); /** * <p>Is <code>true</code> if this is Mac.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_MAC = getOSMatches("Mac"); /** * <p>Is <code>true</code> if this is Mac.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_MAC_OSX = getOSMatches("Mac OS X"); /** * <p>Is <code>true</code> if this is OS/2.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_OS2 = getOSMatches("OS/2"); /** * <p>Is <code>true</code> if this is Solaris.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_SOLARIS = getOSMatches("Solaris"); /** * <p>Is <code>true</code> if this is SunOS.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_SUN_OS = getOSMatches("SunOS"); /** * <p>Is <code>true</code> if this is a POSIX compilant system, * as in any of AIX, HP-UX, Irix, Linux, MacOSX, Solaris or SUN OS.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.1 */ public static final boolean IS_OS_UNIX = IS_OS_AIX || IS_OS_HP_UX || IS_OS_IRIX || IS_OS_LINUX || IS_OS_MAC_OSX || IS_OS_SOLARIS || IS_OS_SUN_OS; /** * <p>Is <code>true</code> if this is Windows.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS = getOSMatches(OS_NAME_WINDOWS_PREFIX); /** * <p>Is <code>true</code> if this is Windows 2000.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS_2000 = getOSMatches(OS_NAME_WINDOWS_PREFIX, "5.0"); /** * <p>Is <code>true</code> if this is Windows 95.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS_95 = getOSMatches(OS_NAME_WINDOWS_PREFIX + " 9", "4.0"); // JDK 1.2 running on Windows98 returns 'Windows 95', hence the above /** * <p>Is <code>true</code> if this is Windows 98.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS_98 = getOSMatches(OS_NAME_WINDOWS_PREFIX + " 9", "4.1"); // JDK 1.2 running on Windows98 returns 'Windows 95', hence the above /** * <p>Is <code>true</code> if this is Windows ME.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS_ME = getOSMatches(OS_NAME_WINDOWS_PREFIX, "4.9"); // JDK 1.2 running on WindowsME may return 'Windows 95', hence the above /** * <p>Is <code>true</code> if this is Windows NT.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS_NT = getOSMatches(OS_NAME_WINDOWS_PREFIX + " NT"); // Windows 2000 returns 'Windows 2000' but may suffer from same JDK1.2 problem /** * <p>Is <code>true</code> if this is Windows XP.</p> * * <p>The field will return <code>false</code> if <code>OS_NAME</code> is * <code>null</code>.</p> * * @since 2.0 */ public static final boolean IS_OS_WINDOWS_XP = getOSMatches(OS_NAME_WINDOWS_PREFIX, "5.1"); //----------------------------------------------------------------------- /** * <p>SystemUtils instances should NOT be constructed in standard * programming. Instead, the class should be used as * <code>SystemUtils.FILE_SEPARATOR</code>.</p> * * <p>This constructor is public to permit tools that require a JavaBean * instance to operate.</p> */ public SystemUtils() { super(); } //----------------------------------------------------------------------- /** * <p>Gets the Java version number as a <code>float</code>.</p> * * <p>Example return values:</p> * <ul> * <li><code>1.2f</code> for JDK 1.2 * <li><code>1.31f</code> for JDK 1.3.1 * </ul> * * @return the version, for example 1.31f for JDK 1.3.1 * @deprecated Use {@link #JAVA_VERSION_FLOAT} instead. * Method will be removed in Commons Lang 3.0. */ public static float getJavaVersion() { return JAVA_VERSION_FLOAT; } /** * <p>Gets the Java version number as a <code>float</code>.</p> * * <p>Example return values:</p> * <ul> * <li><code>1.2f</code> for JDK 1.2 * <li><code>1.31f</code> for JDK 1.3.1 * </ul> * * <p>Patch releases are not reported. * Zero is returned if {@link #JAVA_VERSION_TRIMMED} is <code>null</code>.</p> * * @return the version, for example 1.31f for JDK 1.3.1 */ private static float getJavaVersionAsFloat() { if (JAVA_VERSION_TRIMMED == null) { return 0f; } String str = JAVA_VERSION_TRIMMED.substring(0, 3); if (JAVA_VERSION_TRIMMED.length() >= 5) { str = str + JAVA_VERSION_TRIMMED.substring(4, 5); } try { return Float.parseFloat(str); } catch (Exception ex) { return 0; } } /** * <p>Gets the Java version number as an <code>int</code>.</p> * * <p>Example return values:</p> * <ul> * <li><code>120</code> for JDK 1.2 * <li><code>131</code> for JDK 1.3.1 * </ul> * * <p>Patch releases are not reported. * Zero is returned if {@link #JAVA_VERSION_TRIMMED} is <code>null</code>.</p> * * @return the version, for example 131 for JDK 1.3.1 */ private static int getJavaVersionAsInt() { if (JAVA_VERSION_TRIMMED == null) { return 0; } String str = JAVA_VERSION_TRIMMED.substring(0, 1); str = str + JAVA_VERSION_TRIMMED.substring(2, 3); if (JAVA_VERSION_TRIMMED.length() >= 5) { str = str + JAVA_VERSION_TRIMMED.substring(4, 5); } else { str = str + "0"; } try { return Integer.parseInt(str); } catch (Exception ex) { return 0; } } /** * Trims the text of the java version to start with numbers. * * @return the trimmed java version */ private static String getJavaVersionTrimmed() { if (JAVA_VERSION != null) { for (int i = 0; i < JAVA_VERSION.length(); i++) { char ch = JAVA_VERSION.charAt(i); if (ch >= '0' && ch <= '9') { return JAVA_VERSION.substring(i); } } } return null; } /** * <p>Decides if the java version matches.</p> * * @param versionPrefix the prefix for the java version * @return true if matches, or false if not or can't determine */ private static boolean getJavaVersionMatches(String versionPrefix) { if (JAVA_VERSION_TRIMMED == null) { return false; } return JAVA_VERSION_TRIMMED.startsWith(versionPrefix); } /** * <p>Decides if the operating system matches.</p> * * @param osNamePrefix the prefix for the os name * @return true if matches, or false if not or can't determine */ private static boolean getOSMatches(String osNamePrefix) { if (OS_NAME == null) { return false; } return OS_NAME.startsWith(osNamePrefix); } /** * <p>Decides if the operating system matches.</p> * * @param osNamePrefix the prefix for the os name * @param osVersionPrefix the prefix for the version * @return true if matches, or false if not or can't determine */ private static boolean getOSMatches(String osNamePrefix, String osVersionPrefix) { if (OS_NAME == null || OS_VERSION == null) { return false; } return OS_NAME.startsWith(osNamePrefix) && OS_VERSION.startsWith(osVersionPrefix); } //----------------------------------------------------------------------- /** * <p>Gets a System property, defaulting to <code>null</code> if the property * cannot be read.</p> * * <p>If a <code>SecurityException</code> is caught, the return * value is <code>null</code> and a message is written to <code>System.err</code>.</p> * * @param property the system property name * @return the system property value or <code>null</code> if a security problem occurs */ private static String getSystemProperty(String property) { try { return System.getProperty(property); } catch (SecurityException ex) { // we are not allowed to look at this property System.err.println("Caught a SecurityException reading the system property '" + property + "'; the SystemUtils property value will default to null."); return null; } } /** * <p>Is the Java version at least the requested version.</p> * * <p>Example input:</p> * <ul> * <li><code>1.2f</code> to test for JDK 1.2</li> * <li><code>1.31f</code> to test for JDK 1.3.1</li> * </ul> * * @param requiredVersion the required version, for example 1.31f * @return <code>true</code> if the actual version is equal or greater * than the required version */ public static boolean isJavaVersionAtLeast(float requiredVersion) { return JAVA_VERSION_FLOAT >= requiredVersion; } /** * <p>Is the Java version at least the requested version.</p> * * <p>Example input:</p> * <ul> * <li><code>120</code> to test for JDK 1.2 or greater</li> * <li><code>131</code> to test for JDK 1.3.1 or greater</li> * </ul> * * @param requiredVersion the required version, for example 131 * @return <code>true</code> if the actual version is equal or greater * than the required version * @since 2.0 */ public static boolean isJavaVersionAtLeast(int requiredVersion) { return JAVA_VERSION_INT >= requiredVersion; } /** * Returns whether the {@link #JAVA_AWT_HEADLESS} value is <code>true</code>. * * @return <code>true</code> if <code>JAVA_AWT_HEADLESS</code> is <code>"true"</code>, * <code>false</code> otherwise. * * @see #JAVA_AWT_HEADLESS * @since 2.1 * @since Java 1.4 */ public static boolean isJavaAwtHeadless() { return JAVA_AWT_HEADLESS != null ? JAVA_AWT_HEADLESS.equals(Boolean.TRUE.toString()) : false; } /** * <p>Gets the Java home directory as a <code>File</code>.</p> * * @return a directory * @throws SecurityException if a security manager exists and its * <code>checkPropertyAccess</code> method doesn't allow * access to the specified system property. * @see System#getProperty(String) * @since 2.1 */ public static File getJavaHome() { return new File(System.getProperty(JAVA_HOME_KEY)); } /** * <p>Gets the Java IO temporary directory as a <code>File</code>.</p> * * @return a directory * @throws SecurityException if a security manager exists and its * <code>checkPropertyAccess</code> method doesn't allow * access to the specified system property. * @see System#getProperty(String) * @since 2.1 */ public static File getJavaIoTmpDir() { return new File(System.getProperty(JAVA_IO_TMPDIR_KEY)); } /** * <p>Gets the user directory as a <code>File</code>.</p> * * @return a directory * @throws SecurityException if a security manager exists and its * <code>checkPropertyAccess</code> method doesn't allow * access to the specified system property. * @see System#getProperty(String) * @since 2.1 */ public static File getUserDir() { return new File(System.getProperty(USER_DIR_KEY)); } /** * <p>Gets the user home directory as a <code>File</code>.</p> * * @return a directory * @throws SecurityException if a security manager exists and its * <code>checkPropertyAccess</code> method doesn't allow * access to the specified system property. * @see System#getProperty(String) * @since 2.1 */ public static File getUserHome() { return new File(System.getProperty(USER_HOME_KEY)); } }