I'm trying to catch a 'specific' exception (FormatException^ or OverflowException^) and then re throw it and catch it in the 'general' exception (Exception^) catch block.
When run, I give it a format exception through input. I then get this error in a dialog box:
"An unhandled exception of type 'System.FormatException' occurred in FutureValue.exe
Additional information: Input string was not in a correct format."
When I click 'break' it takes me to line # 232.
Here is the partial code:
try
{
...
}
catch(FormatException^ ex)
{
MessageBox::Show("FormatException Occured. Message: " + ex->Message);
throw;
}
***line# 232*** catch(OverflowException^ ex)
{
MessageBox::Show("Overflow Occured. Message: " + ex->Message);
throw;
}
catch(Exception^ ex)
{
MessageBox::Show("TESTING");
}
The rethrow expression (throw without assignment_expression) causes the originally thrown object to be rethrown. Because the exception has already been caught at the scope in which the rethrow expression occurs, it is rethrown out to the next dynamically enclosing try block. Therefore, it cannot be handled by catch blocks at the scope in which the rethrow expression occurred.
Taking above into account, you may want to write your code like this:
try
{
try
{
//...
}
catch(FormatException^ ex)
{
MessageBox::Show("FormatException Occured. Message: " + ex >Message);
throw;
}
catch(OverflowException^ ex)
{
MessageBox::Show("Overflow Occured. Message: " + ex->Message);
throw;
}
}
catch(Exception^ ex)
{
MessageBox::Show("TESTING");
}
is there a try catch block above this?
You just threw an exception with the throw statement, nobody is catching it.
The debugger has taken you to where the exception was thrown
Related
What exactly is eating an exception?
Is it when there's nothing in the catch block or when you don't log the exception?
I understand that this is eating an exception.
try {
//exception code
} catch (Exception e) {
}
However, what about this?
try {
//exception code
} catch (Exception e) {
System.out.println("Exception Thrown");
}
When there is nothing in the catch block.
In general it is necessary to catch the more specific exception if it is possible to recover that exception and if not log the exception and rethrown it.
A program that "eat" exception is a bad practice because could be in an inconsistent state.
Assume there are two member functions f1(), f2() of an object O2.
Consider below code.
O2::f2()
{
if(somestring.length()<20)
{
throw
}
}
O2::f1()
{
try
{
f2()
}
catch(...)
{
//Some handling
}
}
Here ideally f1 should catch exception thrown by exception. But it is not happening. Instead,
getting error as shown below:
Terminated without any active exception
This is because f2 has an empty throw statement. If that statement is executed without an active exception being handled, terminate is supposed to be called.You need to throw something in order to catch
My mysql is down so it should throw error which should be caught in catch block. But it doesn't.
try {
Class.forName(driver)
ConnectionPool.singleton(url, username, password)
}
catch {
case _ => logger.error("Unable to connect to Database")
}
Your exception is ignored with Try(...) statement.
If you check value of your connection variable, it's most likely be smth like Failure(... exception ... )
I have few similar methods and there calls as follows :
methodThrowingException() throws NullPointerException, InterruptedException, TimeoutException {
<method logic>
}
Calling class :
try{
methodThrowingExceptions();
<some other logic>
}
catch (NullPointerException npx) {
npx.printStackTrace();
log more details...
}
catch (InterruptedException inx) {
inx.printStackTrace();
log more details...
}
catch (TimeoutException tox) {
tox.printStackTrace();
log more details..
}
How (if) can I put all of these three in one Custom Exception?
Other than (1) is there a way to optimise the code so that I need not write the entire same statements for multiple methods?
Since Java 7, you can use a multi-catch block:
catch (NullPointerException | InterruptedException | TimeoutException e) {
e.printStackTrace();
log more details...
}
That said, you should never catch NullPointerException: that is a bug, and if it happens, the exception should bubble up. You can't reasonably expect a NPE to happen.
In addition, doing the same thing for an InterruptedException as for the other exceptions is also very dubious. When catching an InterruptedException, you should reset the interrupted flag on the current thread, and stop what you're doing ASAP.
I'm looking to check what type of exception is retruned in the following code snippet.
I'm not sure exactly how to do it though, or if it's even possible.
try {
//SOME LOGIC
} catch (exception ex) {
System.debug(//EXCEPTION TYPE);
}
Would anyone have any suggestions or advice??
try {
//SOME LOGIC
} catch (Exception ex) {
System.err.println(ex.getClass().getName());
}
Few things:
You have posted exception. I assume you meant Exception.
System.debug does not exist.
I have answered your specific question but obviously this is not standard exception handling code. You will instead output the stacktrace, log the exception or rethrow a different one.
Firstly, within your catch block(s), specify the exception. Semantically, types including Exception are not in camel case.
Secondly, you can obtain the exception type through Exception.getClass().getName():
catch (Exception exception) {
System.out.println(exception.getClass().getName());
// exception.printStackTrace();
// throw exception;
}
Specified by:http://docs.oracle.com/javase/7/docs/api/java/lang/Exception.html
After some searching around I found an answer,
try {
//SOME LOGIC
} catch (Exception ex) {
System.debug(ex.getTypeName());
}
The getTypeName() method does the trick nicely.
I apologise for not specifying I was working in Apex in my question.