Java执行Linux命令并返回命令结果

2010-08-25 14:43:00|  分类：Linux环境下C|  标签：|字号大中小 订阅

Java 可以通过 Runtime 调用Linux命令，形式如下：

Runtime.getRuntime().exec(command)

但是这样执行时没有任何输出，因为调用 Runtime.exec 方法将产生一个本地的进程，并返回一个Process子类的实例（注意：Runtime.getRuntime().exec（command）返回的是一个Process类的实例）该实例可用于控制进程或取得进程的相关信息。

由于调用 Runtime.exec 方法所创建的子进程没有自己的终端或控制台，因此该子进程的标准IO（如stdin,stdou,stderr）都通过 Process.getOutputStream()，Process.getInputStream()， Process.getErrorStream() 方法重定向给它的父进程了。

用户需要用这些stream来向子进程输入数据或获取子进程的输出，下面的代码可以取到 linux 命令的执行结果：

try {

String[] cmd = new String[]{”/bin/sh”, “-c”, ” ls “};

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);

} catch (Exception e) {

e.printStackTrace();

}

 

 

package com.cisco.learning;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

public class Ys {

 public static void main(String[] args) throws IOException {

  Process exec = Runtime.getRuntime().exec("notepad");

  InputStream inputStream = exec.getInputStream();

  InputStreamReader inputStreamReader = new InputStreamReader(inputStream);

  BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

  StringBuilder stringBuilder = new StringBuilder(10);

  try {

   String tmp;

   while ((tmp = bufferedReader.readLine()) != null) {

    stringBuilder.append(tmp);

   }

  } catch (IOException e) {

   e.printStackTrace();

  } finally {

   bufferedReader.close();

  }

  System.out.println(stringBuilder.toString());

 }

}

 

 

 

package com.cisco.learning;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

public class Ys {

 public static void main(String[] args) throws IOException {

  Process exec = Runtime.getRuntime().exec("notepad");

  InputStream inputStream = exec.getInputStream();

  InputStreamReader inputStreamReader = new InputStreamReader(inputStream);

  BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

  StringBuilder stringBuilder = new StringBuilder(10);

  try {

   String tmp;

   while ((tmp = bufferedReader.readLine()) != null) {

    stringBuilder.append(tmp);

   }

  } catch (IOException e) {

   e.printStackTrace();

  } finally {

   bufferedReader.close();

  }

  System.out.println(stringBuilder.toString());

 }

}