Helpers for java.lang.System
/*
* 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.
*/
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 595798 2007-11-16 20:01:43Z 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 dev@commons.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>Is <code>true</code> if this is Windows Vista.</p>
*
* <p>The field will return <code>false</code> if <code>OS_NAME</code> is
* <code>null</code>.</p>
*
* @since 2.4
*/
public static final boolean IS_OS_WINDOWS_VISTA = getOSMatches(OS_NAME_WINDOWS_PREFIX, "6.0");
//-----------------------------------------------------------------------
/**
* <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));
}
}
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