Selecting Results

After the Action processes the request, a result is selected to provide the response. A result may simply forward to a HTML page, or a JavaServer page, a FreeMaker or Velocity template, or the result might construct a PDF or some other complex report. There may be multiple results available to an action mapping. To indicate which one to select, the Action class returns a name corresponding to the appropriate result.

<action name="helloName2" class="tutorial.HelloName2">
  <result name="success">HelloName2-success.jsp</result>
  <result name="error">HelloName-error.jsp</result>
</action>

So far, our results have used the default type, Dispatcher. The Dispatcher forwards to another web resource. Other kinds of views can be used by specifying a different result type.

Configuring Result Types

The struts-default package defines result types for the Result classes provided with the framework. If your package uses a custom result type, you can add it to your package.

<xwork>
   <include name="struts-default.xml"/>
   <package name="default" extends="struts-default">

      <result-types>
        <result-type name="Image" class="tutorial.ImageResult" />
      </result-types>

      <action name="Image" class="tutorial.Image">
        <result name="success" type="Image"/>
     </action>
   </package>
</xwork>

Configuring Global Results

It's not unusual for mappings to share a need for the same result. For example, if your application is secure, then many mappings might need to return "login" if the security check fails. Rather than define a common result in every action mapping, the framework lets you define global results.

<package name="default" extends="struts-default">
   <global-results>
      <result name="login" type="redirect-action">login</result>
      <result name="unauthorized">Unauthorized.jsp</result>
   </global-results>
   <!-- other package declarations -->
</package>

Summary

The framework offers a variety of result types. An Action can select the appropriate result by name, without actually knowing what result type will be rendered. If a result is needed by multiple action mappings, it can be defined once as a global result.