old_contents: from opensubmitexec.compiler import JAVAC
  
  
  def validate(job):
  
      # Make sure that the right file name is given
      job.ensure_files(['HelloWorld.java'])
  
      # Run the compiler
      job.run_compiler(compiler=JAVAC, inputs=['HelloWorld.java'])
  
      # Run the compilation result.
      job.run_program('java HelloWorld')
  
new_contents: from opensubmitexec.compiler import JAVAC
  
  
  def validate(job):
  
      if not job.ensure_files(['HelloWorld.java']):
          job.send_fail_result("Your submitted file must be named 'HelloWorld.java'.", "Student used wrong file name.")
  
      job.run_compiler(compiler=JAVAC, inputs=['HelloWorld.java'])
  
      # Run the compilation result.
      job.run_program('java HelloWorld')
  
subject: Fix Java example