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SuddenIllegalStateException: Solved(?)

SuddenIllegalStateException: Solved(?)

2004-01-02       - By Merrill Cornish

 Back
Reply:     1     2  

Well--I think I've found the cause for my sudden IllegalStateException,
although I'm still not sure why.

Because it was claiming an IllegalStateException, and it was pointing to
the sendRedirect() statement, I assumed the sendRedirect() was the
CAUSE. So--

I started probing the code by inserting

  response.sendRedirect(<page_name>);
  return;

By putting this pair of statements in various places, I was able to
deduce that the problem was occurring in a subroutine that accessed the
MySQL database.  Furthermore, if only the first part of the subroutine
was executed (as it would be with an invalid login name), it worked, but
if the full subroutine was executed (valid login name), it failed.

At that point, I noticed that if I clicked on the brower's Back Button,
the sendRedirect() that I had suspected of being the culprit had
actually worked.  Hmmmm.  So, I tried simply inserting extra return
statements in the code rather than the sendRedirect()/return shown
above.  Lo and behold, I got a SQLException from the suspect subroutine
I had been probing.

Shortly before the problem started occurring (remember the "suddenly"
part of my message subject?), I had removed a certain field from the
database table, but I was still asking JDBC to get() that field value.  
That, of course, was an error (MY error) and fully worthy of an
exception, but the question was why did it cause the error it did.

I apears my error handling  needs some work.  I'm going to post a
separate question about catch{} to try to find out what I'm doing wrong.

In the meantime, thanks to Howard and Ben for their offers of help.

Merrill

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