How do I run a batch file from my Java Application?

Question

In my Java application, I want to run a batch file that calls "scons -Q implicit-deps-changed build\file_load_type export\file_load_type"

It seems that I can't even get my batch file to execute. I'm out of ideas.

This is what I have in Java:

Runtime.
   getRuntime().
   exec("build.bat", null, new File("."));

Previously, I had a Python Sconscript file that I wanted to run but since that didn't work I decided I would call the script via a batch file but that method has not been successful as of yet.

Answer 1

Batch files are not an executable. They need an application to run them (i.e. cmd).

On UNIX, the script file has shebang (#!) at the start of a file to specify the program that executes it. Double-clicking in Windows is performed by Windows Explorer. CreateProcess does not know anything about that.

Runtime.
   getRuntime().
   exec("cmd /c start \"\" build.bat");

Note: With the start \"\" command, a separate command window will be opened with a blank title and any output from the batch file will be displayed there. It should also work with just `cmd /c build.bat", in which case the output can be read from the sub-process in Java if desired.

Answer 2

Sometimes the thread execution process time is higher than JVM thread waiting process time, it use to happen when the process you're invoking takes some time to be processed, use the waitFor() command as follows:

try{    
    Process p = Runtime.getRuntime().exec("file location here, don't forget using / instead of \\ to make it interoperable");
    p.waitFor();

}catch( IOException ex ){
    //Validate the case the file can't be accesed (not enought permissions)

}catch( InterruptedException ex ){
    //Validate the case the process is being stopped by some external situation     

}

This way the JVM will stop until the process you're invoking is done before it continue with the thread execution stack.

Answer 3

Runtime runtime = Runtime.getRuntime();
try {
    Process p1 = runtime.exec("cmd /c start D:\\temp\\a.bat");
    InputStream is = p1.getInputStream();
    int i = 0;
    while( (i = is.read() ) != -1) {
        System.out.print((char)i);
    }
} catch(IOException ioException) {
    System.out.println(ioException.getMessage() );
}

Answer 4

To run batch files using java if that's you're talking about...

String path="cmd /c start d:\\sample\\sample.bat";
Runtime rn=Runtime.getRuntime();
Process pr=rn.exec(path);`

This should do it.

Answer 5

ProcessBuilder is the Java 5/6 way to run external processes.

Answer 6

The executable used to run batch scripts is cmd.exe which uses the /c flag to specify the name of the batch file to run:

Runtime.getRuntime().exec(new String[]{"cmd.exe", "/c", "build.bat"});

Theoretically you should also be able to run Scons in this manner, though I haven't tested this:

Runtime.getRuntime().exec(new String[]{"scons", "-Q", "implicit-deps-changed", "build\file_load_type", "export\file_load_type"});

EDIT: Amara, you say that this isn't working. The error you listed is the error you'd get when running Java from a Cygwin terminal on a Windows box; is this what you're doing? The problem with that is that Windows and Cygwin have different paths, so the Windows version of Java won't find the scons executable on your Cygwin path. I can explain further if this turns out to be your problem.

Answer 7

Process p = Runtime.getRuntime().exec( 
  new String[]{"cmd", "/C", "orgreg.bat"},
  null, 
  new File("D://TEST//home//libs//"));

tested with jdk1.5 and jdk1.6

This was working fine for me, hope it helps others too. to get this i have struggled more days. :(

Answer 8

I had the same issue. However sometimes CMD failed to run my files. That's why i create a temp.bat on my desktop, next this temp.bat is going to run my file, and next the temp file is going to be deleted.

I know this is a bigger code, however worked for me in 100% when even Runtime.getRuntime().exec() failed.

// creating a string for the Userprofile (either C:\Admin or whatever)
String userprofile = System.getenv("USERPROFILE");

BufferedWriter writer = null;
        try {
            //create a temporary file
            File logFile = new File(userprofile+"\\Desktop\\temp.bat");   
            writer = new BufferedWriter(new FileWriter(logFile));

            // Here comes the lines for the batch file!
            // First line is @echo off
            // Next line is the directory of our file
            // Then we open our file in that directory and exit the cmd
            // To seperate each line, please use \r\n
            writer.write("cd %ProgramFiles(x86)%\\SOME_FOLDER \r\nstart xyz.bat \r\nexit");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                // Close the writer regardless of what happens...
                writer.close();
            } catch (Exception e) {
            }

        }

        // running our temp.bat file
        Runtime rt = Runtime.getRuntime();
        try {

            Process pr = rt.exec("cmd /c start \"\" \""+userprofile+"\\Desktop\\temp.bat" );
            pr.getOutputStream().close();
        } catch (IOException ex) {
            Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex);

        }
        // deleting our temp file
        File databl = new File(userprofile+"\\Desktop\\temp.bat");
        databl.delete();

Answer 9

The following is working fine:

String path="cmd /c start d:\\sample\\sample.bat";
Runtime rn=Runtime.getRuntime();
Process pr=rn.exec(path);

Answer 10

This code will execute two commands.bat that exist in the path C:/folders/folder.

Runtime.getRuntime().exec("cd C:/folders/folder & call commands.bat");

Answer 11

To expand on @Isha's anwser you could just do the following to get the returned output (post-facto not in rea-ltime) of the script that was run:

try {
    Process process = Runtime.getRuntime().exec("cmd /c start D:\\temp\\a.bat");
    System.out.println(process.getText());
} catch(IOException e) {
    e.printStackTrace();
}