How to get output from a .bat process to display in a JTextPane?

Question

My program requires that I run a .bat file which will compile java source. This is running fine, however I am looking for a solution which will get the output (and possible errors) of compile.bat and add it to a text pane on a GUI. I have the following code, however when executed the process happens without printing anything to the pane and without any errors.

GenerationDebugWindow.main(null);

Process process = rut.exec(new String[] {file.getAbsolutePath() + "\\compile.bat"});
Scanner input = new Scanner(process.getInputStream());

InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader reader = new BufferedReader(isr);

String line;
int exit = -1;

while ((line = reader.readLine()) != null) {
    // Outputs your process execution
    try {
        exit = process.exitValue();
        GenerationDebugWindow.writeToPane(line);
        System.out.println(line);
        if (exit == 0)  {
            GenerationDebugWindow.writeToPane("Compilation Finished!");
            if(new File(file + "/mod_" + WindowMain.modName.getText()).exists()){
                GenerationDebugWindow.writeToPane("Compilation May Have Experienced Errors.");
            }
        }
    } catch (IllegalThreadStateException t) {

    }
}

GenerationDebugWindow

private static JTextPane outputPane;
public static void writeToPane(String i){
    outputPane.setText(outputPane.getText() + i + "\r\n");
}

did you _read_ the javadocs for `Process.exitValue()` before adding the call to your code, or just stick the catch block in your code because the IDE told you to? — jtahlborn, Jul 21 '12 at 00:41

score 2 · Accepted Answer · answered Jul 21 '12 at 00:45

2

Use:

Runtime.getRuntime().exec( "cmd.exe /C " + file.getAbsolutePath() + "\\compile.bat" );

answered Jul 21 '12 at 00:45

Reimeus

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score 1 · Answer 2 · edited May 23 '17 at 12:13

Reference this question: Java Process with Input/Output Stream

It's likely that the output of the process is going to the error stream. However, ProcessBuilder is a more useful class than directly using System.getRuntime().exec()

In the example below, we're telling the ProcessBuilder to redirect the error stream to the same stream as the output goes to, which simplifies the code.

ProcessBuilder builder = new ProcessBuilder("cmd.exe /C " + file.getAbsolutePath() + "\\compile.bat");
builder.redirectErrorStream(true);
builder.directory(executionDirectory); // if you want to run from a specific directory
Process process = builder.start();
Reader reader = ...;
String line = null;
while ((line = reader.readLine ()) != null) {
    System.out.println ("Stdout: " + line);
}

int exitValue = process.exitValue();

Andrew Thompson · Answer 3 · 2012-07-21T03:00:00.480

0

My program requires that I run a .bat file which will compile java source.

Your users on *nix and OS X require that source be compiled using the JavaCompiler.

The STBC is an example of using the JavaCompiler. It is open source. It uses a JTextArea as opposed to a JTextPane to hold the source and errors, but should be trivial to adapt.

Compilation error Compiled successfully

edited Jul 21 '12 at 03:00

answered Jul 21 '12 at 02:47

Andrew Thompson

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How to get output from a .bat process to display in a JTextPane?

3 Answers3