February 22, 2010

Struts 1.x error: Request does not contain handler parameter named

If you ever got this error in your Struts 1.x application:

You are probably calling your action (which is extending DispatchAction) without passing in the appropriate parameter for the method.
Let me explain:

In you struts-config.xml file you probably have an action mapping like the following :


<action path="/search" name="searchBean"
 type="com.mypackage.actions.SearchAction"
 scope="request" validate="false"
 input="/createSearch.jsp" parameter="add">  
 <forward name="success" path="/createSearch.jsp"></forward>  
</action>

And in your Action class you probably defined two methods like add() and edit().

The value of the of PARAMETER_VALUE should not be the 'name' of the method you defined in your Action class (eg. add()). It should be the name of a 'parameter' which you will use to pass in the method's name:

Solution:

  1. Change parameter="add" to parameter="function"
  2. Wherever you are calling your Search.do action pass in the parameter like this:
       localhost/StrutsApplication/Search.do?function=add
       localhost/StrutsApplication/Search.do  //calling this will throw the error above
    

Another way to avoid this issue is to have a MappingDispatchAction extend your class instead of the DispatchAction. There's also a rant I found from another developer on this topic if you want to get into it further http://frustratedprogrammer.blogspot.com/2004/07/struts-121-mappingdispatchaction.html

I was going through the book Struts - The Complete Reference by James Holmes when I first ran into this problem.

Hope this helps somebody, because I remember banging my head for some time when I first ran into it a few years ago.

2 comments:

sanganak-guru said...

To me, this is gr8 post containing precise information to rectify the issue I was facing while working on Action class containing multiple actions/business methods.

Thanks a lot.

Gut Feeling said...

Although I haven't solved my problem, this was extremely useful to me as it has eliminated a few areas for me. It's the most useful post I've found on the net so far. Thankyou