Executing another application from Java

Question

I need to execute a batch file which executes another Java application. I don't care whether it executes successfully or not and I don't have to capture any errors.

Is it possible to do this with ProcessBuilder? What are the consequences if I do not capture errors?

However, my requirement is just to execute another Java application.

Answer 1

I assume that you know how to execute the command using the ProcessBuilder.

Executing a command from Java always should read the stdout and stderr streams from the process. Otherwise it can happen that the buffer is full and the process cannot continue because writing its stdout or stderr blocks.

Answer 2

If you don't care about the return value you could just use Runtime.getRuntime().exec("path.to.your.batch.file");

Answer 3

http://www.devdaily.com/java/java-exec-processbuilder-process-1
this may be helpfull

Answer 4

You could simply use Runtime.exec()

Answer 5

The Runtime.getRuntime().exec() approach is quite troublesome, as you'll find out shortly.

Take a look at the Apache Commons Exec project. It abstracts you way of a lot of the common problems associated with using the Runtime.getRuntime().exec() and ProcessBuilder API.

It's as simple as:

String line = "myCommand.exe";
CommandLine commandLine = CommandLine.parse(line);
DefaultExecutor executor = new DefaultExecutor();
executor.setExitValue(1);
int exitValue = executor.execute(commandLine);

Answer 6

You can execute a batch instruction, or a any application using

Runtime.getRuntime().exec(cmd);

• cmd is the command or te application path.

Also yo can wait for executiong and getting the return code (to check if its executed correctly) with this code:

  Process p = Runtime.getRuntime().exec(cmd);
  p.waitFor();
  int exitVal = p.exitValue();

You have a full explanation of different types of calls here http://www.rgagnon.com/javadetails/java-0014.html

Answer 7

Yes it is possible using ProcessBuilder.

ProcessBuilder example:

import java.io.*;
import java.util.*;

public class CmdProcessBuilder {
  public static void main(String args[]) 
     throws InterruptedException,IOException 
  {
    List<String> command = new ArrayList<String>();
    command.add(args[0]);


    ProcessBuilder builder = new ProcessBuilder(command);
    Map<String, String> environ = builder.environment();

    final Process process = builder.start();
    InputStream is = process.getInputStream();
    InputStreamReader isr = new InputStreamReader(is);
    BufferedReader br = new BufferedReader(isr);
    String line;
    while ((line = br.readLine()) != null) {
      System.out.println(line);
    }
    System.out.println("Program terminated!");
  }
}

Check these examples:

http://www.rgagnon.com/javadetails/java-0014.html

http://www.java-tips.org/java-se-tips/java.util/from-runtime.exec-to-processbuilder.html