HELP: Inheritance question: Overriding a method.

Question

Hi all.
I have one class: BatchJob.java which defines the following method:
(1) protected void handleException(Exception e) {
     setInitError( true );
     printTrace(getClass().getName(), "*** ERROR: " + e.toString());
     createMailError(e);
Another class JBDCBatchJob.java which extends BatchJob, overrides the previous method like this:
(2) protected void handleException(SQLException sqlEx) {
     setInitError( true );
     printTrace(getClass().getName(), getSqlQuery(), sqlEx);
     createMailError(getSqlQuery(), sqlEx);
where getSqlQuery() is a getter for a String member field which contains the last SQL query sent to the JDBC Driver.
In another class (say SimpleJDBCBatchJob) which extends JDBCBatchJob, I've got the following code fragment:
try {
// statements that may throw SQLException or in general Exception
catch (Exception e) {
handleException( e );
I have realized that the method invoked by the JVM when an SQLException is thrown in SimpleJDBCBatchJob is (1), that is, the "handleException" defined in BatchJob and not that in JDBCBatchJob which it should (or at least, that's what I meant). Why is it? Is it possible to accomplish this without having to rename the method (2), I mean, using method overriding? Any idea would be highly appreciated. THANKS in advance.

Answer 1

You didn't override the method handleException in JBDCBatchJob, you just overloaded it. So int JBDCBatchJob, you actually had two versions of handleException, one that took a parameter of the type Exception, one that took a parameter of the type SQLException.
So, in SimpleJDBCBatchJob, you need to have a catch block like
try {
// statements that may throw SQLException or in general Exception
catch (SQLException sqle) {
handleException( sqle );
catch (Exception e) {
handleException( e );
This would call your handleException in BatchJob if a general exception was thrown, and the handleException in JBDCBatchJob if a SQLException was thrown from the try block.
Hope that makes things clearer for you.
Alan