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When an Action class method completes, it returns a String. The value of the String is used to select a result element. An action mapping will often have a set of results representing different possible outcomes. A standard set of result tokens are defined by the ActionSupport base class.

String SUCCESS = "success";
String NONE    = "none";
String ERROR   = "error";
String INPUT   = "input";
String LOGIN   = "login";

...

The result element has two jobs. First, it provides a logical name. An Action can pass back a token like "success" or "error" without knowing any other implementation details. Second, the result element provides a Result Typeresult type. Most results simply forward to a server page or template, but other Result Types can be used to do more interesting things.

Intelligent Defaults

A default Result Type can be set as part of the configuration for each packageEach package may set a default result type to be used if none is specified in a result element. If one package extends another, the "child" package can set its own default result, or inherit one from the parent.

<result-types>
   <result-type name="dispatcher" default="true"
                class="org.apache.struts2.dispatcher.ServletDispatcherResult" 
  default="true"/>
</result-types>

If a type attribute is not specified, the framework will use the dispatcher. The default Result Type, dispatcher type, which forwards to another web resource. If the resource is a JavaServer Page, then the container will render it, using its JSP engine.

...

<action name="Hello">
    <result>/hello/Result.jsp</result>
    <result name="error">/hello/Error.jsp</result>
    <result name="input">/hello/Input.jsp</result>
</action>

...

<global-results>
    <result name="error">/Error.jsp</result>
    <result name="invalid.token">/Error.jsp</result>
    <result name="login" type="redirect-actionredirectAction">Logon!input</result>
</global-results>

...

private String nextAction;

public String getNextAction() {
    return nextAction;
}

...

<action name="fragment" class="FragmentAction">
    <result name="next" type="redirect-actionredirectAction">${nextAction}</result>
</action>

...