Solved

best practices for custom Exceptions

Posted on 2013-02-05
3
294 Views
Last Modified: 2013-02-11
Is it good/normal practice to call another class to do something from inside a customException?

I want to clearly identify to an executive thread when something goes wrong in a weblogic producer class.  I was thinking about uniquely catching all the various JMS exceptions, but want to throw one unique exception identifying that the weblogic interface has encountered a problem.  I was thinking about defining and throwing a custom exception, and inside that class notifying the executive/main class to do some things?  Is this the correct methodology?
0
Comment
Question by:dpalyca755
3 Comments
 
LVL 21

Expert Comment

by:Amitkumar Panchal
ID: 38858283
0
 

Author Comment

by:dpalyca755
ID: 38862631
For better context of my question:
I want to create a JMS Producer class which will continually attempt to connect if it can't connect on instantiation of the object itself or if onException is called denoting a connection failure.

Is the generic example I sketched out below the correct paradigm to do so?
---------------------------------------------------------------------
public class MyProducer implements ExceptionListener {
        public MyProducer() {
                super();
                createConnection();
        }
 
        private void createConnection() {
            try {
                try {
                     // set up connection
                     // status as successful.
                } catch (NamingException ne) {
                        ne.printStackTrace(System.err);
                        throw CustomException;
                } catch (JMSException jmse) {
                        jmse.printStackTrace(System.err);
                        throw CustomException;
                }
             catch CustomException (e) {
               createConnection();
             }
 
        }
 
        public void onException(javax.jms.JMSException jsme) {
                jsme.printStackTrace();
        }
               createConnection();
        }
 
        public synchronized void publishMessage(String Text) {
          // build and send message 
       }
} 

Open in new window

0
 
LVL 26

Accepted Solution

by:
dpearson earned 500 total points
ID: 38862942
No - you don't want to do it like that.

The problem is that if you get an error,  you will end up with an ever growing stack of "createConnection" calls because you are calling yourself in the exception handler.

This means if you run this for long enough (let's say maybe 100,000 messages with 10% of them triggering an error) you'll eventually run out of stack space and the whole process and server will crash.  That's an ugly error as it'll work fine for a long long time in testing before it fails with an "OutOfMemory" exception and the world's biggest stack trace.

A better model is just to use a loop:
createConnection() {
    boolean done = false  ;
    while (!done) {
       try {
                   // set up connection
                   // status as successful.
                  done = true ; // Stop trying to connect
           } catch (Exception ex) {
                 // Perhaps log the exception...
                done = false ; // Not really needed but makes the point
           }
       }
    }
}

Open in new window


Does that make sense?

Doug
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
groupSumClump challenge 9 102
PDFBox - convert image to PDF, PDF resolution 3 117
Unable to start eclipse ? 17 132
maven project error 5 48
After being asked a question last year, I went into one of my moods where I did some research and code just for the fun and learning of it all.  Subsequently, from this journey, I put together this article on "Range Searching Using Visual Basic.NET …
Java Flight Recorder and Java Mission Control together create a complete tool chain to continuously collect low level and detailed runtime information enabling after-the-fact incident analysis. Java Flight Recorder is a profiling and event collectio…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
This video teaches viewers about errors in exception handling.

910 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

Need Help in Real-Time?

Connect with top rated Experts

22 Experts available now in Live!

Get 1:1 Help Now