Java如何调用外部命令？

Java如何调用外部外部命令？

我自己的体会是用Runtime.getRuntime.exec(cmd);

譬如下面这个代码：

String[] cmd = new String[3]；

if( osName.equals( "Windows NT" )||osName.equals( "Windows 2000" ))

    {

     cmd[0] = "cmd.exe" ;

     cmd[1] = "/C" ;

    }

else if(osName.equals("Linux"))

   {

     cmd[0]="sh"

      cmd[1]＝linux下的某个目录

   }

    else if( osName.equals( "Windows 98" ) )

    {

     cmd[0] = "command.com" ;

     cmd[1] = "/C" ;

    }

    cmd[2] = "mysqldump --opt -u root yh_tpl > "+backup_path+filename+".sql";

    Process ps = Runtime.getRuntime().exec(cmd); 

今天看到了别人回复这类问题，有这样一点以前不知道：

java中调用exec完全脱离了java的jvm，因此以后的运行环境需要自己维护。

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 Java调用外部程序的方法

作者：陈刚，桂林人,97年毕业于广西师范大学数学系，暂于IBM中国研究中心兼职从事软件开发(2004.2-?)，专注基于java平台的软件开发。

email: [email protected]

blog: glchengang.yeah.net

最近开发报表模块，生成报表文件后(一个Excel文件)要将此文件打。很简单，使用Java调用外部程序的方法即可。代码如下：

String path = "C:/报表_20040504.xls";

try {

　　//相当于window的"开始"->"运行"的效果

Runtime.getRuntime().exec("cmd /c start " + path);

} catch (IOException e) {

e.printStackTrace();

}

但如果文件的路径中包含有空格上面的方法就会出错。到google狂搜一气,没有,看cmd /?帮助也没有,试了好多次,发现解决办法其实很简单,真是愚昧。代码如下，无须多言。

String path = "C:/Documents and Settings/Giles/桌面/报表_20040504.xls";

try {

Runtime.getRuntime().exec("cmd /c start excel /"" + path + "/"");

} catch (IOException e) {

e.printStackTrace();

}

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<script language=Javascript1.2 src="../scripts/watermark.js"></script>

Execute an external program

This example will

capture

the output (from stdio) of an external program.

import java.io.*; public class CmdExec { public 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 argv[]) { new CmdExec("myprog.bat"); } }

[myprog.bat] echo hello world!

NOTE 1: Reading a BAT file output containing the dir command may hang. I don't know why...

NOTE 2: To make a shortcut : Create a shortcut to CmdExec.class. Go in the shortcut properties and change the

target

as "java CmdExec". Change the

run

option to Minimized to hide the black DOS console when the BAT is executed.

NOTE 3 : A useful link on the subject : JavaWorld article, thanks to O. Thomann.

The following example

start a Dial-up connection

on the Win plateform :

[Dialup.java] public class Dialup { public static void main(String[] args) throws Exception { Process p = Runtime.getRuntime().exec("dialup.bat"); p.waitFor(); System.out.println("Done."); } }

The BAT file contains the DOS call to bring the Dialog. The "MyConnection" is the DUN and it's case sensitive.

[dialup.bat] rundll32.exe rnaui.dll,RnaDial MyConnection

You still need to press ENTER to CONNECT, there is an option in the Connection properties to connect automatically.

If you want to wait until the BAT file is finished, use "start /wait".

[dialup.bat] start /wait rundll32.exe rnaui.dll,RnaDial MyConnection

On NT and W2K, rnaui.dll is not available. Use rasdial.exe instead.

rasdial "connection name" rasdial "connection name" /d to drop rasdial /? for more options

To launch a

Unix script

String[] cmd = {"/bin/sh", "-c", "ls > hello"}; Runtime.getRuntime().exec(cmd);

You can include a path for the program to be executed. On the Win plateform, you need to put the path in quotes if

the path contains spaces

in it.

public class Test { public static void main(String[] args) throws Exception { Process p = Runtime.getRuntime().exec( "/"c:/program files/windows/notepad.exe/""); p.waitFor(); } }

If you need to

pass arguments

, it's safer to a String array especially if they contain spaces.

String[] cmd = { "myProgram.exe", "-o=This is an option" }; Runtime.getRuntime().exec(cmd);

PDF (Windows only)

[ShowPDF.java] public class ShowPDF { public static void main(String[] args) throws Exception { Process p = Runtime.getRuntime().exec("showpdf.bat mypdf.pdf"); p.waitFor(); System.out.println("Done."); } } [showpdf.bat] rundll32 url.dll,FileProtocolHandler %1

VBSCRIPT

// Win9x Runtime.getRuntime().exec("start myscript.vbs"); // WinNT Runtime.getRuntime().exec("cmd /c start myscript.vbs");

HTML Help (Windows only)

Runtime.getRuntime().exec("hh.exe myhelpfile.chm");

Any program using the Windows file association mechanism

where "file" is the filename of the data file ex. myresume.doc to start Word if the doc extension is associated with it.

Runtime.getRuntime().exec ("rundll32 SHELL32.DLL,ShellExec_RunDLL " + file.getAbsolutePath());