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