Java: How to check for null pointers efficiently

Question

There are some patterns for checking whether a parameter to a method has been given a null value.

First, the classic one. It is common in self-made code

Answer 1

There is no vote for this one, but I use a slight variation of #2, like

erStr += nullCheck (varName, String errMsg); // returns formatted error message

Rationale: (1) I can loop over a bunch of arguments, (2) The nullCheck method is tucked away in a superclass and (3) at the end of the loop,

if (erStr.length() > 0)
    // Send out complete error message to client
else
    // do stuff with variables

In the superclass method, your #3 looks nice, but I wouldn't throw an exception (what is the point, somebody has to handle it, and as a servlet container, tomcat will ignore it, so it might as well be this()) Regards, - M.S.