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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";

...

Using these intelligent defaults, the most often used result types also become the simplest.

<result name="success" type="dispatcher">
    <param name="location">/ThankYou.jsp</param>
</result>

<result>
    <param name="location">/ThankYou.jsp</param>
</result>

The param tag sets a property on the Result object. The most commonly-set property is location, which usually specifies the path to a web resources. The param attribute is another intelligent default.

<result>/ThankYou.jsp</result>

Mixing results with intelligent defaults with other results makes it easier to see the "critical path".

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

A special 'other' result can be configured by adding a result with name="*". This result will only be selected if no result is found with a matching name.

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

...

If actions need to share results, a set of global results can be defined for each package. The framework will first look for a local result nested in the action. If a local match is not found, then the global results are checked.

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

...

Result values may be retrieved from its corresponding Action implementation by using EL expressions that access the Action's properties, just like the Struts 2 tag libraries. So given the following Action fragment:

private String nextAction;

public String getNextAction() {
    return nextAction;
}

you might define a result like this:

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

...