Resource handling with errors (freeing resources in doEndTag)

Question

Hi,
          If I have a Custom Tag that allocates resources in doStartTag and frees them
          in doEndTag then it seems to me that I have a problem if there is an
          exception while the body between these two tags is being processed. For
          example, if doEndTag closes a database connection then each time there's an
          error in a page I lose a connection from the pool. This doesn't seem very
          robust.
          Is there any way of guaranteeing that doEndTag is called once soStartTag has
          been called, even if an exception occurs? If not, how do people manage
          resources like this?
          Thanks,
          Andrew
          

Answer 1

If you target JSP 1.2 container, you can implement TryCatchFinally interface:
          http://java.sun.com/j2ee/sdk_1.3/techdocs/api/javax/servlet/jsp/tagext/TryCatchFinally.html
          Andrew Cooke <[email protected]> wrote:
          > Hi,
          > If I have a Custom Tag that allocates resources in doStartTag and frees them
          > in doEndTag then it seems to me that I have a problem if there is an
          > exception while the body between these two tags is being processed. For
          > example, if doEndTag closes a database connection then each time there's an
          > error in a page I lose a connection from the pool. This doesn't seem very
          > robust.
          > Is there any way of guaranteeing that doEndTag is called once soStartTag has
          > been called, even if an exception occurs? If not, how do people manage
          > resources like this?
          > Thanks,
          > Andrew
          Dimitri