Java 中如何读取环境变量

//引用自：http://topic.csdn.net/t/20020318/12/583112.html

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class enviormentPath {

 public static void SYS_CmdExec(String cmdline)  
    {  
        try  
        {  
           String line;  
           Process p = Runtime.getRuntime().exec(cmdline);  
           BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));  
           while((line =  input.readLine())!= null) 
           {  
               System.out.println(line);  
           }  
           input.close();  
     }catch(Exception err)
     {  
           err.printStackTrace();  
        }  
    }
 public static void main(String[] args) {
  //enviormentPath path = new enviormentPath();
  enviormentPath.SYS_CmdExec("cmd.exe /C set");
  
 }

}