ProcessBuilder redirected to standard output

问题

I would like to redirect a java process output towards the standard output of the parent java process.

Using the ProcessBuilder class as follows:

public static void main(String[] args) {
  ProcessBuilder processBuilder = new ProcessBuilder("cmd");
  processBuilder.directory(new File("C:"));   
  processBuilder.redirectErrorStream(true); // redirect error stream to output stream
  processBuilder.redirectOutput(ProcessBuilder.Redirect.INHERIT);
}

I would have expected that the outputs of "cmd", which are like:

are displayed in the DOS console used to run the java program. But nothing is displayed at all in the DOS Console.

In the other threads of discussions, I saw solutions using a BufferedReader class: but here I would like the outputs of the process to be directly displayed in the standard output, without using any BufferedReader or "while reading loop". Is it possible?

Thanks.

回答1:

Try ProcessBuilder.inheritIO() to use the same I/O as the current Java process. Plus you can daisy chain the methods:

ProcessBuilder pb = new ProcessBuilder("cmd")
    .inheritIO()
    .directory(new File("C:"));
pb.start();

回答2:

You did miss a key piece, you actually need to start your process and wait for your output. I believe this will work,

processBuilder.redirectOutput(ProcessBuilder.Redirect.INHERIT);
// Start the process.
try {
  Process p = processBuilder.start();
  // wait for termination.
  p.waitFor();
} catch (IOException e) {
  e.printStackTrace();
} catch (InterruptedException e) {
  e.printStackTrace();
}

来源：https://stackoverflow.com/questions/16134864/processbuilder-redirected-to-standard-output

标签

java

redirect

stream

processbuilder

inheritance