Java运行shell脚本

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。参考了互联网上的这篇文章：http://lee79.javaeye.com/blog/418549（感谢一下），我重新整理了代码。
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）：
??? 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。

?

http://blog.csdn.net/sheismylife/archive/2009/11/17/4817851.aspx