Solved

when/why would a IllegalThreadStateException be thrown?

Posted on 2006-11-16
6
414 Views
Last Modified: 2012-06-27
when/why would a IllegalThreadStateException be thrown?  If I try something by mistake on a thread?  Say start it twice?   Would this be thrown if I were to CTRL+Break a program when it was in that section of code?
I am calling a Runtime process call to execute another program within my code.  I then use a doWaitFor method to send the process to and wait for the program to end if necessary.
I am wondering when the IllegalThreadStateException would be thrown and caught....  

Runtime rprogram = Runtime.getRuntime();
Process p = rprogram.exec(command);
                  
InputStream stderr = p.getErrorStream();
                  
                  
InputStream stdin = p.getInputStream();
                  
exitcodes = doWaitFor(p);




private static int doWaitFor(Process p) {
            
            int exitValue = -1;  // returned to caller when p is finished
            
            try {
                  
            InputStream in  = p.getInputStream();
            InputStream err = p.getErrorStream();
                  
            boolean finished = false; // Set to true when p is finished
                  
                  while( !finished) {
                        try {
                        String input="";
                        String error="";
                        while( in.available() > 0)
                              {
                                    
                            // Print the output of our system call
            Character c = new Character( (char) in.read());
            input=input+c;
                              }
                              
                              
                              
                              
            while( err.available() > 0)
                  {
                                    
            // Print the output of our system call
            Character c = new Character( (char) err.read());
                                    
                  error=error+c;
                  }
                              
                              
                              
                  exitValue = p.exitValue();
                  finished  = true;
                              
                        }
                  catch (IllegalThreadStateException e)
                                               {
                              
                  / Process is not finished yet;
                  // Sleep a little to save on CPU cycles
                  Thread.currentThread().sleep(500);
                  }
            }
                  
                  
            }
            catch (Exception e)
                               {
                  
            // unexpected exception!  print it out for debugging...
                                    
            }
            
            // return completion status to caller
            return exitValue;
}

Thanks
ryno71
0
Comment
Question by:ryno71
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
6 Comments
 
LVL 92

Expert Comment

by:objects
ID: 17960080
that will be thrown if you try and get the exit value before the process has terminated.
0
 

Author Comment

by:ryno71
ID: 17960199
Say by ending the process early?  What steps would you recommend that I take to account for that?

0
 
LVL 92

Expert Comment

by:objects
ID: 17960255
call waitFor() before checking the exitValue
0
Optimize your web performance

What's in the eBook?
- Full list of reasons for poor performance
- Ultimate measures to speed things up
- Primary web monitoring types
- KPIs you should be monitoring in order to increase your ROI

 

Author Comment

by:ryno71
ID: 17960628
while searching I did find that there was an old bug for waitFor(), which is why I tried using the other method above

http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4254231

would waitfor() handle a ctrl+ brk type of scenario?  if not, what should I look into?

thanks
ryno71
0
 
LVL 92

Accepted Solution

by:
objects earned 100 total points
ID: 17960654
should do
0
 

Author Comment

by:ryno71
ID: 18039920
Sorry finally got a vacation, thanks
0

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article is the last of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers our test design approach and then goes through a simple test case example, how …
In this post we will learn different types of Android Layout and some basics of an Android App.
Video by: Michael
Viewers learn about how to reduce the potential repetitiveness of coding in main by developing methods to perform specific tasks for their program. Additionally, objects are introduced for the purpose of learning how to call methods in Java. Define …
This theoretical tutorial explains exceptions, reasons for exceptions, different categories of exception and exception hierarchy.
Suggested Courses

617 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question