Is it possible to share variable between processes in Java with Process Builder

Question

Original message

I'm currently working on several executable Jars being called by another Java process (or "Launcher) called by a scheduler.

To do this, we use ProcessBuilder. However, we need to be able to share variable between the parent process and the child process (The executable JAR).

I know it's possible to pass variable to the child process with the environment() method.

What we need is to be able to share informations from the child process to the parent process (the process results, mostly files). Is it possible? If it is, how so?

Update The two java processes are on the same computer and so share the same disk space. The Launcher process is called by a scheduler and this process cannot be changed.

I know that using a file is probably the best solution but I was wondering if there was no other solution.

Thanks in advance for your help.

Answer 1

A process is a sort of black box with which you can dialogue only via standard streams (input, output, error) or retrieving exit code of the process. All other systems needs an external way to communicate.

So you can:

• Use the method exitValue() of the Process as a form of communication between child and parent.

• Intercept the output of the child process using the getInputStream() method.

• Share data with external resources (files, databases or opening communication sockets for example).