Question

For a project, I need to take a list of git commit Id’s (A couple thousand), and compare them two at a time, saving specific information from the return into a file. The only issue I’m having is getting a diff command to work in Java. I’ve spend hours trying to figure this out and I’m still in need of assistance.

Answer 1

You can run a command and get its result using this :

    ProcessBuilder processBuilder = new ProcessBuilder(command);
    processBuilder.redirectErrorStream(true);
    Process process = processBuilder.start();
    String output = readOutput(process);
    try {
        if (process.waitFor() != 0) {
            throw new IOException(
                "command exited in error: " + process.exitValue()
                    + "\n" + output);
        }
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return output;

So you just have to define the most adapted “git diff…” command for your problem and parse the output.