Use of NullPointerException Catch to Detect NULL Pointer Dereference
Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.
Description
Programmers typically catch NullPointerException under three circumstances:
The program contains a null pointer dereference. Catching the resulting exception was easier than fixing the underlying problem.
The program explicitly throws a NullPointerException to signal an error condition.
The code is part of a test harness that supplies unexpected input to the classes under test.
Of these three circumstances, only the last is acceptable.
Demonstrations
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
Example One
The following code mistakenly catches a NullPointerException.
try {
mysteryMethod();
} catch (NullPointerException npe) {
}See Also
Weaknesses in this category are related to insufficient control flow management.
This category identifies Software Fault Patterns (SFPs) within the Unchecked Status Condition cluster (SFP4).
This category includes weaknesses that occur if a function does not generate the correct return/status code, or if the application does not handle all possible return/...
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