Execute an external program(转载)

原文地址:http://www.rgagnon.com/javadetails/java-0014.html

Using Runtime.exec()

This example will capture the output (from stdio) of an external program.

import java.io.*;

public class CmdExec {



  public static void main(String argv[]) {

    try {

      String line;

      Process p = Runtime.getRuntime().exec

        (System.getenv("windir") +"\\system32\\"+"tree.com /A");

      BufferedReader input =

        new BufferedReader

          (new InputStreamReader(p.getInputStream()));

      while ((line = input.readLine()) != null) {

        System.out.println(line);

      }

      input.close();

    }

    catch (Exception err) {

      err.printStackTrace();

    }

  }

}

Windows CMD (or BAT) file and retrieve the errorlevel or exitcode

// win xp

import java.io.*;

public class CmdExec {

  public static void main(String argv[]) {

    try {

      String line;

      Process p = Runtime.getRuntime().exec("test.cmd");

      p.waitFor();

      System.out.println(p.exitValue());

    }

    catch (Exception err) {

      err.printStackTrace();

    }

  }

}

test.cmd (set the errorlevel manually)

@echo hello world

@exit 42

test.cmd (set the errorlevel 1 (problem detected)

@java -garbage

test.cmd (set the errorlevel 0 (execution Ok)

@java -version

Launch a Unix script

String[] cmd = {"/bin/sh", "-c", "ls > hello"};

Runtime.getRuntime().exec(cmd);

Using the ProcessBuilder

Since 1.5, the ProcessBuilder class provides more controls overs the process to be started. It's possible to set a starting directory.

   

import java.io.*;

import java.util.*;



public class CmdProcessBuilder {

  public static void main(String args[]) 

     throws InterruptedException,IOException 

  {

    List<String> command = new ArrayList<String>();

    command.add(System.getenv("windir") +"\\system32\\"+"tree.com");

    command.add("/A");



    ProcessBuilder builder = new ProcessBuilder(command);

    Map<String, String> environ = builder.environment();

    builder.directory(new File(System.getenv("temp")));



    System.out.println("Directory : " + System.getenv("temp") );

    final Process process = builder.start();

    InputStream is = process.getInputStream();

    InputStreamReader isr = new InputStreamReader(is);

    BufferedReader br = new BufferedReader(isr);

    String line;

    while ((line = br.readLine()) != null) {

      System.out.println(line);

    }

    System.out.println("Program terminated!");

  }

}

Windows rundll32 utility

Windows File association
Any program using the Windows file association mechanism can be started with the rundll32 utility.

// "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());

See also this HowTo about the new Desktop API, the recommended solution (but you need JDK1.6).
See also this one to open the default browser.

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("rundll32.exe rnaui.dll,RnaDial MyConnection");

    p.waitFor();

    System.out.println("Done.");

  }

}

The "MyConnection" is the DUN and it's case sensitive.

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

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

PDF (Windows only)

public class ShowPDF {

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

    Process p = 

      Runtime.getRuntime()

        .exec("rundll32 url.dll,FileProtocolHandler c:/pdf/mypdf.pdf");

    p.waitFor();

    System.out.println("Done.");

  }

}

PDF (Mac only)

public class ShowPDF {

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

    Process p = Runtime.getRuntime().exec("open /Documents/mypdf.pdf");

  }

}

More runddl32 examples

---

Path to executable with spaces in them

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 .

 

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);

If using the start command and the path of the file to be started contains a space then you must specified a title to the start command.

String fileName = "c:\\Applications\\My Documents\\test.doc";

String[] commands = {"cmd", "/c", "start", "\"DummyTitle\"",fileName};

Runtime.getRuntime().exec(commands);

---

VBSCRIPT

// Win9x

Runtime.getRuntime().exec("start myscript.vbs");



// WinNT

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



or



// with a visible console

Runtime.getRuntime().exec("cscript myscript.vbs");



// with no visible console

Runtime.getRuntime().exec("wscript myscript.vbs");

HTML Help (Windows only)

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

Start Excel

import java.io.IOException;



class StartExcel {

    public static void main(String args[])

        throws IOException

    {

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

    }

}

To load a worksheet

import java.io.IOException;



class StartExcel {

    public static void main(String args[])

        throws IOException

    {

        String fileName = "c:\\temp\\xls\\test2.xls";

        String[] commands = {"cmd", "/c", "start", "\"DummyTitle\"",fileName};

        Runtime.getRuntime().exec(commands);

    }

}