打印系统的环境变量

import java.util.*;
public class PropertyTest
{
	public static void main(String args[])
	{
		Properties pro=(Properties)System.getProperties();
		Set set=pro.keySet();
		Iterator ite=set.iterator();
		while(ite.hasNext())
		{
			String str=(String)ite.next();
			String value=(String)pro.get(str);
			System.out.println(str+"="+value);
		}
	}
}