Struts 2: parameters between Actions

问题:

I have the following question: I need to pass a parameter (for example ID ) when I finish a form and the action save the form's values, this will forward to the result = "success" and I need that the action that will be call in the success come with the ID and other parameters to later use in the next form for save this information (info-form2 and info.form1)...

for example:

FORM1 ( USER ) ==== "success" ====> FORM2 ( ADDRESS )

userForm.html ===================> addressForm.html?user_id=X ...(where X : Id passed throw of UserAction (method:save) to AddressAction (method:newAddress))

Please I will appreciate your help

Thanks in advance

回答1:

You used the word "forward" but it sounds like you want to go to a new page (address.html) to collect more information about the address. If this is the case, you need to redirect to the address page after the user action completes.

<action name="user" class="UserAction">
  <!-- Redirect to another namespace -->
  <!-- for Struts 2.2 --> <result type="redirectAction">
  <!-- for Struts 2.0 <result type="redirect-action"> -->
    <param name="actionName">collect-address</param>
    <param name="userId">${userId}</param>
  </result>
</action>

The ${userId} syntax will call getUserId on your UserAction and pass that parameter as you showed in your question: addressForm.html?user_id=X. collect-address can have a success result that goes to addressForm.html. Docs here. If you want to avoid using another action, you can try using the result type="redirect" and pass things through that way.

If you really want to forward, you can use action chaining. This is discouraged by Ted Husted on the Struts2 team but it may work for you.

Instead of action chaining, try to bring all the code to complete this request into a single action and use helper or service classes for User and Address to separate and reuse the code instead of "action chaining".

回答2:

Not very clear what you want to do.

Looks like after successfull execution of an action, the request gets forwarded to another action. In the first action you want to pass parameter ID and use that in the 2nd action. Since both the actions are getting used in the same request call you can save the ID parameter in request like this

request.setAttribute("ID", iDValueObject);

In the second action you can extract the value of ID like this

request.getAttribute("ID");

回答3:

This should work:

  <!--  Package Default -->
    <package name="**default**" extends="struts-default,json-default" namespace="/">
        <action name="noOp" class="com.web.myapp.action.NoOpAction">
           <result name="success" type="chain">
                    <param name="requiresValidation">true</param>
                    <param name="actionName">userAuthentication</param>
                    <param name="namespace">/user</param>
          </result>
        </action>   
    </package>
    <!--  Package User -->
    <package name="user" extends="struts-default,json-default" namespace="/user">
    <action name="userAuthentication" class="com.web.myapp.action.AuthenticateAction">
    ...
    </action>