Programming Clojure, 2nd Edition

Exception Handling

In Java code, exception handling crops up for three reasons:

• Wrapping checked exceptions (see ​Checked Exceptions​ if you are unfamiliar with checked exceptions)

• Using a finally block to clean up nonmemory resources such as file and network handles

• Responding to the problem: ignoring the exception, retrying the operation, converting the exception to a nonexceptional result, and so on

Checked Exceptions

Java’s checked exceptions must be explicitly caught or rethrown from every method where they can occur. This seemed like a good idea at first: checked exceptions could use the type system to rigorously document error handling, with compiler enforcement. Most Java programmers now consider checked exceptions a failed experiment, ...