Learn what causes null pointer exceptions in Java, how to identify them, and how to fix them with simple techniques and best practices. Also, learn how to test and learn more about them.

There is a warning in Effective Java (Second Edition, Item #49) regarding the dangers, including throwing of NullPointerException, related to careless mixing of primitive and reference types.

Here the old exception is caught and a new exception is thrown instead. We loose the information of the original exception. We loose the location where the original exception is thrown. One way to ...

We present NPEX, a new technique for repairing Java null pointer exceptions (NPEs) without tests. State-of-the-art NPE repair techniques rely on test suites written by developers for patch validation.

We envision a world where no exceptions are raised; instead, language semantics are changed so that operations are total functions. Either an operation executes normally or tailored recovery code is ...