rspec/rules/S1696/java/rule.adoc

== Why is this an issue?

``++NullPointerException++`` should be avoided, not caught. Any situation in which ``++NullPointerException++`` is explicitly caught can easily be converted to a ``++null++`` test, and any behavior being carried out in the catch block can easily be moved to the "is null" branch of the conditional.


=== Noncompliant code example

[source,java]
----
public int lengthPlus(String str) {
  int len = 2;
  try {
    len += str.length();
  }
  catch (NullPointerException e) {
    log.info("argument was null");
  }
  return len;
}
----


=== Compliant solution

[source,java]
----
public int lengthPlus(String str) {
  int len = 2;

  if (str != null) {
    len += str.length();
  }
  else {
    log.info("argument was null");
  }
  return len;
}
----


== Resources

* CWE - https://cwe.mitre.org/data/definitions/395[CWE-395 - Use of NullPointerException Catch to Detect NULL Pointer Dereference]
* CERT - https://wiki.sei.cmu.edu/confluence/display/java/ERR08-J.+Do+not+catch+NullPointerException+or+any+of+its+ancestors[ERR08-J. Do not catch NullPointerException or any of its ancestors]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Make the dereference of XXX conditional on its not being null


'''
== Comments And Links
(visible only on this page)

include::../comments-and-links.adoc[]

endif::env-github,rspecator-view[]