CODEWITHSUNDEEP
javaexception
Unhandled Exception
Unhandled Exception

Reputation: 1513

How to find a list of possible Java Exceptions

Lets say your program is going to do a variety of math computations and want to know the available exceptions that are possible to capture to see if any are applicable.

Or, the program will be doing a lot of file i/o and other things and you want to capture specific exceptions instead of simply capturing Exception.

Maybe you may want to know if one application is even applicable in the scenario being coded.

What is the recommended way to go about researching what exceptions are available to be captured when generating code to do specific activity?

Upvotes: 4

Views: 1584

Answers (5)

Eranda
Eranda

Reputation: 1467

There are two types of exceptions, checked and unchecked. If you don't handle checked exception you will get a build failure. You can identify checked exception if you are using any IDE. But unchecked exception are bit tricky and you may need to refer the API documentation to understand what they are, because unless it's thrown you may not know that exception can occur. Again some IDEs give you hints based on your code, for example class casting, null checking.

Upvotes: 0

Karthik
Karthik

Reputation: 5040

Using a IDE like Intellij or Eclipse will let you know most of the exceptions that the library code you are using throws, depending on it's javadoc(Like FileNotFoundException) and majority of the times, these are the exceptions that you should worry about.

Other exceptions like divide by zero, null pointer exception will certainly depend on the code you are writing. For example if you getting an object from a different class, you might want to check if it is null before doing any operations on it. Similarly if you are dividing by something, like K/X , you should have an idea whether X is ever going to be 0 or not.

Upvotes: 2

Peter Lawrey
Peter Lawrey

Reputation: 533462

You can trace through the source of the code you are calling to find all the specific exceptions. The problem with this is that the time this takes esp since it could change between different versions of software is very high.

In general you can trust the Javadoc for broad checked exceptions, but this usually won't tell you about all specific exception or all RuntimeExceptions. (Including all future exceptions)

Note: you may wish to take different actions based on the message as well as the type of exception.

For this reason I suggest you focus on the specific exceptions which you handle differently, and have a catch all IOException or similar for unexpected exception which by their nature mean you can't know how to handle them.

Upvotes: 0

Astrogat
Astrogat

Reputation: 1625

You can usually find this information in the Docs for the method you want to use. It will tell you what exceptions it can throw in what cases. There is no general purpose "find all exceptions" technique. This is probably a good things, because if you don't know how or why an exception is created, you probably don't know enough to handle it.

Upvotes: 0

AlexWien
AlexWien

Reputation: 28727

The recomended way is to look into the javadoc of that method.
Hopefully the software author of that code wrote the javadoc in the recomended way, to also list the Runtime Exceptions that a method throws.

Upvotes: 0

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