Calling shell script from Java by giving a relative path of script location

Question

I am working on a project wherein I have to call my shell script stored at the location where my java files reside.I am currently calling the shell script by giving a hard-coded (absolute) path.I want to make my script run by giving a relative path.Currently I am running my script via this code in Java:

try {
     ProcessBuilder pb2 = new ProcessBuilder("/bin/bash", "/Users/umang/Documents/script.sh", arg);
     Process scriptexec = pb2.start();
     scriptexec.waitFor();
    } catch (Exception e) {
             e.printStackTrace();
             }

Here the arg is the location of the file on which the script runs.The current Implementation works well but the Issue is I have to store my script at some location on the server.Its a webapp which is deployed on apache-tomcat server by making a war file. It would be good to have a relative path and store the script inside the war file when it is being generated.

Attempt #1:

final File executorDirectory = new File("A/B/C/D/E/F/G/H/");
      try {
          ProcessBuilder pb2 = new ProcessBuilder("/bin/bash","combiner.sh",arg);
          pb2.directory(executorDirectory);
          Process scriptexec = pb2.start();
          scriptexec.waitFor();
          System.out.println("Script executed successfully");
      } catch (Exception e) {
          e.printStackTrace();
      }

A/B/C/D/E/F/G/H/ location where my script resides from the top of the application Error: File not found error -2 JavaIOException()

Attempt #2

URL loc=ClassLoader.getSystemResource("script.sh");
try {
     ProcessBuilder pb2 = new ProcessBuilder("/bin/bash", "/Users/umang/Documents/script.sh", arg);
     Process scriptexec = pb2.start();
     scriptexec.waitFor();
    } catch (Exception e) {
             e.printStackTrace();
             }

Error: loc does not get me the path for the script location.In the debugger tool I figured out it gets null.

Since the ClassLoader.getSystemResource returns a URL and ProcessBuilder only accepts String I cannot directly append them.

something like this: http://stackoverflow.com/questions/1900154/classpath-resource-within-jar? — Ueli Hofstetter, Apr 10 '15 at 16:57
@chuchikaeschtli No using the ClassLoader or getResource does not work for me. — Umang Mukesh Mehta, Apr 10 '15 at 17:30
Using `getResource()` to find resources included in the war should work. Maybe you could edit your question to include the code that you wrote to try to do that, and describe how it failed. — Kenster, Apr 10 '15 at 17:48

score 0 · Accepted Answer · answered Apr 11 '15 at 05:37

If this is deployed in tomcat try to put your script in the WEB-INF of your war. Now assuming you start the process from a servlet you could use

ServletContext ctx = getContext();
String pathForProcessBuilder = ctx.getRealPath("/WEB-INF/script.sh");

If you don't want to use the ServletContext, try using

getClass().getClassLoader().getResource("/WEB-INF/script.sh")

instead of using ClassLoader (in order to make sure you use the "correct" classloader, i.e. the one which loaded your class)

Calling shell script from Java by giving a relative path of script location

1 Answers1