Unable to run java commands using processbuilder

Question

I am trying to run a java class file from another java program.

This is my program:

import java.io.File;
import java.io.IOException;
import java.lang.ProcessBuilder.Redirect;
public class RunJava {
    public static void main(String[] args) throws IOException {
        ProcessBuilder pb = new ProcessBuilder("java","HelloWorld");
        pb.directory(new File("/home/local/prasanth-8508"));
        pb.redirectOutput(Redirect.INHERIT);
        pb.redirectError(Redirect.INHERIT);
        pb.start();
    }
}

After running this program I get the following error:

Exception in thread "main" java.io.IOException: Cannot run program "java"

But when I run any java commands from my terminal, they work absolutely fine.

Another thing I found is, when I run the command: echo $PATH in my terminal and using the ProcessBuilder (ProcessBuilder pb = new ProcessBuilder("bash","-c","echo $PATH");), they are showing different outputs. i.e The path to jdk/bin is not displayed in the ProcessBuilder command.

How can I solve this issue?

Answer 1

Yes, As @MichaelBerry said it is possible that you may not have permission to access it but other then that also I want to include,

Here you have started with very good ProcessBuilder you just need to modify small things like parameter -jar in the constructor of processBuilder.

I've posted below sample code which may help you to understand how it will work.

ProcessBuilder pb = new ProcessBuilder("/path/to/java", "-jar", "your.jar");
pb.directory(new File("preferred/working/directory"));
Process p = pb.start();