Best Practices on Exception Handling

We list best practices on exception handling and link to resources on the internet.

Throwing Exceptions

What are best practices for throwing exceptions?

  1. Use Exceptions only for exceptional Conditions
  2. Know Common Exceptions for Reuse
  3. Failure Atomicity
  4. Never fail in Finally Block
  5. Preserve Stack Trace

Handling Exceptions

What are best practices for handling exceptions?

  1. Do not ignore Exceptions
  2. Release Resources
  3. Do not log and throw
  4. Do not catch java.lang.Exception
  5. Catch late
  6. Extract try-catch Blocks

Exceptions in API Design

What are best practices for designing APIs regarding exceptions?

  1. Prefer Exceptions over Return Codes
  2. Document Exceptions with Javadoc
  3. Use own Exceptions in public API
  4. Keep Number of thrown Exceptions small
  5. Declare thrown Subclass Exceptions
  6. Declare thrown RuntimeExceptions
  7. Mind the Level of Abstraction

Designing Exceptions

What should be considered when writing new exception classes?

  1. Use existing Exceptions
  2. Choose a meaningful Name
  3. Subclass Exceptions
  4. Design Exception Class Hierarchy
  5. Know the Exception Categories
  6. Know when to use checked or unchecked Exceptions
  7. Provide useful Information
  8. Provide specific Information
  9. Mind Serialization
  10. Provide a meaningful Message

Using smart-exceptions

What are best practices for using the smart-exceptions library?

  1. Dependency Magnet
  2. Error Code Index
  3. Message Bundles for Exception Codes
  4. Never analyze the Code Parameter in the Catch Block
  5. Adding global Information