java获取所有系统变量

    public static void getSysProp(){
    	Properties props = System.getProperties();
    	Set<Entry<Object,Object>> res = props.entrySet();
        Iterator it = res.iterator(); 
        while (it.hasNext()) 
        {         
                Map.Entry e = (Map.Entry)it.next(); 
                System.out.println(e.getKey()+"="+e.getValue()); 
        }
    	
    }

结果

java.runtime.name=Java(TM) 2 Runtime Environment, Standard Edition
sun.boot.library.path=C:\Program Files\Java\jre1.5.0_16\bin
java.vm.version=1.5.0_16-b02
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
sun.java.launcher=SUN_STANDARD
user.country=CN
sun.os.patch.level=Service Pack 3
java.vm.specification.name=Java Virtual Machine Specification
user.dir=D:\myeclipse-eclipse\workspace\JavaMail
java.runtime.version=1.5.0_16-b02
java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment
java.endorsed.dirs=C:\Program Files\Java\jre1.5.0_16\lib\endorsed
os.arch=x86
java.io.tmpdir=C:\DOCUME~1\WEIJIA~1.ZHO\LOCALS~1\Temp\
line.separator=

java.vm.specification.vendor=Sun Microsystems Inc.
user.variant=
os.name=Windows XP
sun.jnu.encoding=GBK
java.library.path=lib目录
java.class.version=49.0
sun.management.compiler=HotSpot Client Compiler
os.version=5.1
user.home=用户目录
user.timezone=
java.awt.printerjob=sun.awt.windows.WPrinterJob
file.encoding=UTF-8
java.specification.version=1.5
java.class.path=classpath路径
user.name=用户名
java.vm.specification.version=1.0
java.home=C:\Program Files\Java\jre1.5.0_16
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, sharing
java.version=1.5.0_16
java.ext.dirs=C:\Program Files\Java\jre1.5.0_16\lib\ext
sun.boot.class.path=C:\Program Files\Java\jre1.5.0_16\lib\rt.jar;C:\Program Files\Java\jre1.5.0_16\lib\i18n.jar;C:\Program Files\Java\jre1.5.0_16\lib\sunrsasign.jar;C:\Program Files\Java\jre1.5.0_16\lib\jsse.jar;C:\Program Files\Java\jre1.5.0_16\lib\jce.jar;C:\Program Files\Java\jre1.5.0_16\lib\charsets.jar;C:\Program Files\Java\jre1.5.0_16\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.desktop=windows
sun.cpu.isalist=pentium_pro+mmx pentium_pro pentium+mmx pentium i486 i386 i86