利用Runtime.execute方法,我们可以在Java程序中运行Linux的Shell脚本,或者执行其他程序
现在通过CommandHelper.execute方法可以执行命令,该类实现 代码如下: package javaapplication3; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; /** * * @author chenshu */ public class CommandHelper { //default time out, in millseconds public static int DEFAULT_TIMEOUT; public static final int DEFAULT_INTERVAL = 1000; public static long START; public static CommandResult exec(String command) throws IOException, InterruptedException { Process process = Runtime.getRuntime().exec(command); CommandResult commandResult = wait(process); if (process != null) { process.destroy(); } return commandResult; } private static boolean isOverTime() { return System.currentTimeMillis() - START >= DEFAULT_TIMEOUT; } private static CommandResult wait(Process process) throws InterruptedException, IOException { BufferedReader errorStreamReader = null; BufferedReader inputStreamReader = null; try { errorStreamReader = new BufferedReader(new InputStreamReader(process.getErrorStream())); inputStreamReader = new BufferedReader(new InputStreamReader(process.getInputStream())); //timeout control START = System.currentTimeMillis(); boolean isFinished = false; for (;;) { if (isOverTime()) { CommandResult result = new CommandResult(); result.setExitValue(CommandResult.EXIT_VALUE_TIMEOUT); result.setOutput("Command process timeout"); return result; } if (isFinished) { CommandResult result = new CommandResult(); result.setExitValue(process.waitFor()); //parse error info if (errorStreamReader.ready()) { StringBuilder buffer = new StringBuilder(); String line; while ((line = errorStreamReader.readLine()) != null) { buffer.append(line); } result.setError(buffer.toString()); } //parse info if (inputStreamReader.ready()) { StringBuilder buffer = new StringBuilder(); String line; while ((line = inputStreamReader.readLine()) != null) { buffer.append(line); } result.setOutput(buffer.toString()); } return result; } try { isFinished = true; process.exitValue(); } catch (IllegalThreadStateException e) { // process hasn't finished yet isFinished = false; Thread.sleep(DEFAULT_INTERVAL); } } } finally { if (errorStreamReader != null) { try { errorStreamReader.close(); } catch (IOException e) { } } if (inputStreamReader != null) { try { inputStreamReader.close(); } catch (IOException e) { } } } } } CommandHelper类使用了CommandResult对象输出结果错误信息。该类实现 代码如下: package javaapplication3; /** * * @author chenshu */ public class CommandResult { public static final int EXIT_VALUE_TIMEOUT=-1; private String output; void setOutput(String error) { output=error; } String getOutput(){ return output; } int exitValue; void setExitValue(int value) { exitValue=value; } int getExitValue(){ return exitValue; } private String error; /** * @return the error */ public String getError() { return error; } /** * @param error the error to set */ public void setError(String error) { this.error = error; } } 现在看看调用代码的演示(main函数接受一个超时参数): 代码如下: public static void main(String[] args) { try { int timeout = Integer.parseInt(args[0]); CommandHelper.DEFAULT_TIMEOUT = timeout; CommandResult result = CommandHelper.exec("mkdir testdir"); if (result != null) { System.out.println("Output:" + result.getOutput()); System.out.println("Error:" + result.getError()); } } catch (IOException ex) { System.out.println("IOException:" + ex.getLocalizedMessage()); } catch (InterruptedException ex) { System.out.println("InterruptedException:" + ex.getLocalizedMessage()); } } 结果会创建一个testdir目录。 我尝试用这种方法创建通过ssh登录到远程机器,遇到两个问题: 1)如果希望没有人机对话方式,则需要使用命令sshpass -p password ssh user@targetIP 'command' 2) 在NetBeans上直接运行工程是不行的,因为权限不够,需要在终端里运行java javaapplication3.Main 3) 很多命令不能运行,只有如pwd等命令可以运行,原因还不清楚,最好改用Ganymed SSH-2库或者其他类似Java库,我会在下一篇文章中介绍如何使用。