Java – How to add a timeout value when using Java’s Runtime.exec()

execjavaprocessruntimetimeout

I have a method I am using to execute a command on the local host. I'd like to add a timeout parameter to the method so that if the command being called doesn't finish in a reasonable amount of time the method will return with an error code. Here's what it looks like so far, without the ability to timeout:

public static int executeCommandLine(final String commandLine,
                                     final boolean printOutput,
                                     final boolean printError)
    throws IOException, InterruptedException
{
    Runtime runtime = Runtime.getRuntime();
    Process process = runtime.exec(commandLine);

    if (printOutput)
    {
        BufferedReader outputReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
        System.out.println("Output:  " + outputReader.readLine());
    }

    if (printError)
    {
        BufferedReader errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
        System.out.println("Error:  " + errorReader.readLine());
    }

    return process.waitFor();
}

Can anyone suggest a good way for me to implement a timeout parameter?

Best Solution

If you're using Java 8 or later you could simply use the new waitFor with timeout:

Process p = ...
if(!p.waitFor(1, TimeUnit.MINUTES)) {
    //timeout - kill the process. 
    p.destroy(); // consider using destroyForcibly instead
}