public static void main(String[] args) {

		
		Properties properties = System.getProperties()  ;
		
		for(Map.Entry<?, ?> entry : properties.entrySet()){
			System.out.println( entry.getKey() 
					 + "-->" + entry.getValue() ); 
		}
		System.out.println( System.getProperty("##########################") ); 
		Map<String , String> map = System.getenv() ; 
		for(Map.Entry<?, ?> entry : map.entrySet()){
			System.out.println( entry.getKey() 
					 + "-->" + entry.getValue() ) ;  
		} 
	}

系统输出这样的结果：
java.runtime.name-->Java(TM) SE Runtime Environment

sun.boot.library.path-->E:softJAVAjdk1.6.0_21jrebin

java.vm.version-->17.0-b17

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-->F:httpclient

java.runtime.version-->1.6.0_21-b07

java.awt.graphicsenv-->sun.awt.Win32GraphicsEnvironment

java.endorsed.dirs-->E:softJAVAjdk1.6.0_21jrelibendorsed

os.arch-->x86

java.io.tmpdir-->C:DOCUME~1ADMINI~1LOCALS~1Temp

line.separator-->

java.vm.specification.vendor-->Sun Microsystems Inc.

user.variant-->

os.name-->Windows XP

sun.jnu.encoding-->GBK

java.library.path-->E:softJAVAjdk1.6.0_21bin;.;C:WINDOWSSunJavabin;C:WINDOWSsystem32;C:WINDOWS;C:WINDOWSsystem32;C:WINDOWS;C:WINDOWSSystem32Wbem;E:softJAVAjdk1.6.0_21bin;E:softapache-maven-3.0.4bin;

java.specification.name-->Java Platform API Specification

java.class.version-->50.0

sun.management.compiler-->HotSpot Client Compiler

os.version-->5.1

user.home-->C:Documents and SettingsAdministrator

user.timezone-->