Java运行系统命令行并获取返回值

来源URL：http://accptlq.iteye.com/blog/1490890

方法一

    Process p = Runtime.getRuntime().exec("ping 127.0.0.1 -t");
    Process p = Runtime.getRuntime().exec("javac");
    InputStream is = p.getInputStream();
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    String line;
    while((line = reader.readLine())!= null){
        System.out.println(line);
    }
    p.waitFor();
    is.close();
    reader.close();
    p.destroy();

方法二

package com.cmd;

import java.lang.*;
import java.io.*;

public class Process {
　　public static void main(String[] args) {

　　 	java.lang.Process process = null;
　　    try {
　　        process = Runtime.getRuntime().exec("net user");
　　        ByteArrayOutputStream resultOutStream = new ByteArrayOutputStream();
　　        InputStream errorInStream = new BufferedInputStream(process.getErrorStream());
　　        InputStream processInStream = new BufferedInputStream(process.getInputStream());
　　        int num = 0;
　　        byte[] bs = new byte[1024];
　　        while((num=errorInStream.read(bs))!=-1){
　　            resultOutStream.write(bs,0,num);
　　        }
　　        while((num=processInStream.read(bs))!=-1){
　　           resultOutStream.write(bs,0,num);
　　        }
　　        String result=new String(resultOutStream.toByteArray());
　　        System.out.println(result);
　　        errorInStream.close(); errorInStream=null;
　　        processInStream.close(); processInStream=null;
　　        resultOutStream.close(); resultOutStream=null;
　　    } catch (IOException e) {
　　        e.printStackTrace();
　　    }finally{
　　        if(process!=null) process.destroy();
　　        process=null;
　　    }
    }
    
}

Runtime.exec() 不等同于直接执行command line命令！啊，我算是在这里吃了苦头了。Runtime.exec()很有局限性，对有些命令不能直接把command line里的内容当作String参数传给exec().比如重定向等命令。
举个例子: 

javap -l xxx > output.txt 

这时要用到exec的第二种重载，即input 参数为String[]:

Process p = Runtime.getRuntime().exec(new String[]{"/bin/sh","-c","javap -l xxx > output.txt"});

 

import java.io.InputStreamReader;  
import java.io.LineNumberReader;  
import java.util.ArrayList;  
import java.util.List;  
  
  
public class test{  
    /**  
     * 运行shell脚本  
     * @param shell 需要运行的shell脚本  
     */    
     public static void execShell(String shell){  
    
        try {    
            Runtime rt = Runtime.getRuntime();    
            rt.exec(shell);    
        } catch (Exception e) {    
            e.printStackTrace();    
        }    
     }

    /**  
     * 运行shell  
     *   
     * @param shStr  
     *            需要执行的shell  
     * @return  
     * @throws IOException  
     */    
    public static List runShell(String shStr) throws Exception {    
        List strList = new ArrayList();    
    
        Process process;    
        process = Runtime.getRuntime().exec(new String[]{"/bin/sh","-c",shStr},null,null);    
        //process = Runtime.getRuntime().exec(shStr);    
        InputStreamReader ir = new InputStreamReader(process    
                .getInputStream());    
        LineNumberReader input = new LineNumberReader(ir);    
        String line;    
        process.waitFor();    
        while ((line = input.readLine()) != null){    
            System.out.println(line);  
            strList.add(line);    
        }    
            
        return strList;    
    }
      
    public static void main(String []arge)throws Exception {  
          
        test t=new test();  
        t.runShell("/home/ubuntu/soft/tomcat/bin/startup.sh")  
    } 

String[] cmd = new String[]{"/bin/sh","-c", " ps -ef"};
Process ps = Runtime.getRuntime().exec(cmd);
BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream()));
StringBuffer sb = new StringBuffer();
String line;
while ((line = br.readLine()) != null) {
    sb.append(line).append("\n");
}
String result = sb.toString();
System.out.println(result);