How to trace a NullPointerException in a chain of getters

by

NPE is the most useless Exception in Java, period. It seems to be always lazily implemented and never tells exactly what caused it, even as simple as “class x.y.Z is null” would help a lot in debugging such cases.

Anyway, the only good way I’ve found to find the NPE thrower in these cases is the following kind of refactoring:

someObject.getSomething()
          .getSomethingElse()
          .getAnotherThing()
          .getYetAnotherObject()
          .getValue();

There you have it, now NPE points to correct line and thus correct method which threw the actual NPE. Not as elegant solution as I’d want it to be, but it works.

More Related Contents:

  1. Android, NullPointerException
  2. How to fix “Method in class cannot be applied to given types” error?
  3. What is a NullPointerException, and how do I fix it?
  4. What is a stack trace, and how can I use it to debug my application errors?
  5. Which @NotNull Java annotation should I use?
  6. What are Java command line options to set to allow JVM to be remotely debugged?
  7. java.lang.NullPointerException is thrown using a method-reference but not a lambda expression
  8. JavaFX Location is not set error message [duplicate]
  9. Printing Java Collections Nicely (toString Doesn’t Return Pretty Output)
  10. Filter values only if not null using lambda in Java8
  11. Why does int num = Integer.getInteger(“123”) throw NullPointerException?
  12. How do you tell if a checkbox is selected in Selenium for Java?
  13. Android: Pass data(extras) to a fragment
  14. How to use conditional breakpoint in Eclipse?
  15. When is it OK to catch NullPointerException?
  16. NoSuchFieldError Java
  17. Eclipse – debugger doesn’t stop at breakpoint
  18. Why does null reference print as “null”
  19. Why should one use Objects.requireNonNull()?
  20. Java conditional operator ?: result type
  21. Html/Javascript debugging in JavaFX WebView
  22. Spring Boot – Environment @Autowired throws NullPointerException
  23. How to get arguments passed to method that called this method?
  24. NullPointerException stack trace not available without debug agent
  25. How to detect when a variable changes value
  26. Java remote debugging, how does it work technically?
  27. Is there a performance difference between Javac debug on and off?
  28. Breakpoint at exception in Eclipse – how to examine Exception object?
  29. Why does the Eclipse debugger give the error “Source not found” seemingly without reason?
  30. Best way of invoking getter by reflection

Leave a Comment