TIOBE - Java Coding Standard

Rule: Design17

Synopsis:	Avoid using equals() to compare against null
Language:	Java
Severity Level:	1
Category:	Design

Description:

Inexperienced programmers sometimes confuse comparison concepts and use equals() to compare to null.

class Bar {
   void foo() {
       String x = "foo";
       if (x.equals(null)) { // bad!
        doSomething();
       }
   }
}