Ajax, Struts and a Null Pointer

I've recently developed a simple ajax search. The whole code in my server is using Struts, so I had to use a somewhat cumbersome way of programming. My main method retu开发者_StackOverflow社区rns an ActionForward. I programmed in a way that I would send the text to the client, and then return a null action forward.

This works perfectly.

...except, it generates a Null Pointer error in the log. And our production log usually sends an email every time an error occur. How can I get rid of this error? Is there any other way (that doesn't involve another framework)?

Thanks!

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When you say your "Main method" are you refering to your Action Class? If this is called via ajax, you can set your return type to void.

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The cause of the NPE might exist in your application, not in struts. I found myself facing the same issue today, and was really puzzled. Struts supports returning a null ActionForward, so there is no reason to get an NPE.

So I dug into the NPE and found that it was being thrown by a class belonging to our application. This class inherits the struts DispatchAction class, and is in turn inherited by all the action classes in our application.

To make a long story short, although struts supported a null ActionForward, the descendent class did not. Once I tweaked the descendent class to handle null values, the NPE went away.