java系统属性

系统属性是指与用户程序相关的操作系统配置信息以及软件信息。通常与用户程序相关的属性关键字包括：

　　●file.separator:文件分隔符，Windows环境下为“"，Unix环境下为“/”；

　　●user.home：用户主目录；

　　●java.home：Java实时运行环境的安装目录；

　　●java.ext.dirs：JDK的安装目录；

　　●os.name：操作系统名称；

　　●user.name：用户登录名称；

　　●os.version：操作系统版本；

　　●path.separator：当前操作系统的路径分隔符；

　　●user.dir：当前用户程序所在目录。

如果想要查看所有的系统属性，可以编写如下代码sysEnv.java

import java.util.Iterator;
import java.util.Properties;

public class sysEnv {
 
 public static void main(String args[])
 {
  Properties props=System.getProperties();
  Iterator iter=props.keySet().iterator();
  while(iter.hasNext())
  {
  String key=(String)iter.next();
  System.out.println(key+" = "+ props.get(key));
  }
 }


}

运行此java代码，就可以看到所有的系统属性和对应的值了。

例如，我本机运行后的结果：

 java.runtime.name = Java(TM) 2 Runtime Environment, Standard Edition
 sun.boot.library.path = C:/j2sdk1.4.2_09/jre/bin
 java.vm.version = 1.4.2_09-b05
 java.vm.vendor = Sun Microsystems Inc.
 java.vendor.url = http://java.sun.com/
 path.separator = ;
 java.vm.name = Java HotSpot(TM) Client VM
 file.encoding.pkg = sun.io
 user.country = CN
 sun.os.patch.level = Service Pack 2
 java.vm.specification.name = Java Virtual Machine Specification
 user.dir = E:/eclipse/testDemo
 java.runtime.version = 1.4.2_09-b05
 java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironment
 java.endorsed.dirs = C:/j2sdk1.4.2_09/jre/lib/endorsed
 os.arch = x86
 java.io.tmpdir = C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp/
 line.separator =
 java.vm.specification.vendor = Sun Microsystems Inc.
 user.variant =
 os.name = Windows XP
 sun.java2d.fontpath =
 java.library.path = C:/j2sdk1.4.2_09/bin;.;C:/WINDOWS/system32;C:/WINDOWS;C:/j2sdk1.4.2_09/bin;d:/oracle/ora92/bin;C:/Program Files/Oracle/jre/1.1.8/bin;C:/WINDOWS/system32;C:/WINDOWS;C:/WINDOWS/System32/Wbem;D:/MySQL/MySQL Server 4.1/bin;d:/Program Files/IDM Computer Solutions/UltraEdit-32
 java.specification.name = Java Platform API Specification
 java.class.version = 48.0
 java.util.prefs.PreferencesFactory = java.util.prefs.WindowsPreferencesFactory
 os.version = 5.1
 user.home = C:/Documents and Settings/Administrator
 user.timezone =
 java.awt.printerjob = sun.awt.windows.WPrinterJob
 file.encoding = GBK
 java.specification.version = 1.4
 java.class.path = E:/eclipse/testDemo/bin;E:/eclipse/lucene-1.4.3/lucene-2.0.0/lucene-2.0.0/lucene-core-2.0.0.jar;E:/Library/commons/commons-io-1.1.jar;E:/Library/commons/commons-net-1.1.0.jar;F:/everyday/6月/15/je-analysis-1[1].2.2.jar;E:/Library/junit/junit.jar
 user.name = Cral
 java.vm.specification.version = 1.0
 java.home = C:/j2sdk1.4.2_09/jre
 sun.arch.data.model = 32
 user.language = zh
 java.specification.vendor = Sun Microsystems Inc.
 awt.toolkit = sun.awt.windows.WToolkit
 java.vm.info = mixed mode
 java.version = 1.4.2_09
 java.ext.dirs = C:/j2sdk1.4.2_09/jre/lib/ext
 sun.boot.class.path = C:/j2sdk1.4.2_09/jre/lib/rt.jar;C:/j2sdk1.4.2_09/jre/lib/i18n.jar;C:/j2sdk1.4.2_09/jre/lib/sunrsasign.jar;C:/j2sdk1.4.2_09/jre/lib/jsse.jar;C:/j2sdk1.4.2_09/jre/lib/jce.jar;C:/j2sdk1.4.2_09/jre/lib/charsets.jar;C:/j2sdk1.4.2_09/jre/classes
 java.vendor = Sun Microsystems Inc.
 file.separator = /
 java.vendor.url.bug = http://java.sun.com/cgi-bin/bugreport.cgi
 sun.io.unicode.encoding = UnicodeLittle
 sun.cpu.endian = little
 sun.cpu.isalist = pentium i486 i386