Java Application Error Messages
We found the following (and other!) error messages during functional testing of a client/server Java application that linked barcode information to websites.
Repeated execution of the test bed while monitoring system resources demonstrated a consistent decline in memory, or what is termed a "memory leak." How do these memory leaks happen? An application asks the operating system for a block of memory, uses that memory to perform some function or task, then returns the memory back to the operating system when finished with the task. If the "return" step is omitted, a memory leak has occurred. After enough memory has been "eaten," an error message similar to the following will occur:
We encounter null pointer exceptions quite frequently when testing Java applications. At the time it is accessed, the pointer should contain a valid reference to somewhere in memory, but instead is "null," meaning it contains no reference. Here's a sample null pointer error message:
