List of all possible APEX Exceptions

Question

I have read the documentation and searched but can't seem to find an answer to this.

I am creating a method for portal, I need to pass any errors back to the front end portal in a way that the front end designer can present them to the user in a way the user will understand (instead of the raw error message).

I want to map friendly messages to the common exceptions we might expect to get. But short of causing the code to error and reading the message I can't find a way to find all possible messages.

Is there not somewhere a reference of all possible errors? I can find how to catch say DML errors, but I can't find any reference of what all the possible return messages might be.

Does such a thing exist?

Answer 1

There's two categories of exceptions: normal exceptions and DML exceptions. The Exception class outlines all the possible code exceptions you can expect, with short descriptions of each, while Core Data Types/StatusCode describes all the possible DmlException StatusCode values you might encounter. I'm not going to paste all of the possible values in to this answer, as those messages tend to change on a fairly frequent basis.

Just know that the Exception class in the Apex Code Developer's Guide shows all the possible non-DML exceptions, like NullPointerException and TypeException, while the SOAP API Developer's Guide contains a list of DML-related exceptions. It's probably not worth converting non-DML exceptions to "friendly messages," because they represent things that a developer would be concerned about, not messages that you'd expect the average user to understand.

Answer 2

Here they are:

AsyncException
CalloutException
DmlException
EmailException
ExternalObjectException
InvalidParameterValueException
LimitException
JSONException
ListException
MathException
NoAccessException
NoDataFoundException
NoSuchElementException
NullPointerException
QueryException
RequiredFeatureMissing
SearchException
SecurityException
SerializationException
SObjectException
StringException
TypeException
VisualforceException
XmlException

Source is here.

Answer 3

There are many built-in Exception classes, and they are documented in quite a few locations, as noted by Caspar and sfdcfox. If you think catching all built-in Exception classes covers the gammut, however, you are sorely mistaken, as there are innumerable custom extensions to the Exception class, depending on the context org. In practice, this means that covering all the built-in types is not a comprehensive approach.

public MyCustomUndocumentedException extends Exception { }

Answer 4

One exception not mentioned yet is System.AssertException() which is fatal (and thus cannot be caught in a catch block).

You won't see this normally unless you're using System.assert() in your code but it is worth noting. It can be good practice to use these in production code, and if you're working with code written by someone else then you may encounter them.

Obviously, though, you are most likely to find them in test classes!