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());

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자료 출처: http://www.rgagnon.com/javadetails/java-0014.html

또 하나의 자료: http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps_p.html

또 다른 자료: http://java.ittoolbox.com/groups/groups.asp?v=java-l&i=506252

Runtime 과 Process 를 사용하여 외부명령, 내부명령 실행하는 여러 가지 예들