Catching errors
The first step in correctly managing any exception is to begin by catching it correctly. Apex allows developers to do this using the try-catch-finally
syntax, shown as follows:
try { //Run some code } catch(ExceptionType ex) { //Handle the exception appropriately } finally { //Perform some final clean up code }
A try
statement must have a catch
or finally
block associated with it in order for the code to compile correctly.
In the catch
statement, we can specify a type of exception that we want to handle, for example:
try { Account acc = null; acc.Name = 'Test'; //This will throw a //NullPointerException - see Chapter 1 } catch(NullPointerException ex) { //Handle the exception }
Note that if in this code we had a QueryException
thrown instead of a NullPointerException
, the catch
block would not have caught...