Java Reference
In-Depth Information
//getters and setters
// ...
public String execute() {
return "SUCCESS";
}
public void validate(){
if("".equals(getUsername())){
addFieldError("username", getText("username.required"));
}
if("".equals(getPassword())){
addFieldError("password", getText("password.required"));
}
}
}
Interceptors
Interceptors promote the separation of concerns by separating the implementation of the cross-cutting
concerns from the action. Struts 2 comes with a set of prebuilt interceptors and interceptor stacks
that you can use out of the box. Listing 4-7 illustrates the declaration of an action that belongs to a
package that extends the
struts-default
package, which contains the default set of interceptors.
Listing 4-7. Declaring an Action
<package name="default" namespace="/" extends="struts-default">
<action name="helloAction"
class="HelloWorldAction" >
<result name="success">/hello.jsp</result>
</action>
</package>
When you extend your package from the
struts-default
package, by default the
defaultStack
will
be used for all the actions in your package. The
defaultStack
is configured in the
struts-default.xml
file, and it provides all the core Struts 2 functionality. The
struts-default.xml
file is located in the
struts 2-core.jar
file. To map other interceptors to an action, you can use the
interceptor-ref
element, as illustrated in Listing 4-8.
Listing 4-8. Mapping Interceptors to the Action
<package name="default" namespace="/" extends="struts-default">
<action name="helloAction"
class="HelloWorldAction" >
<interceptor-ref name="logger"/>
<result name="success">/hellot.jsp</result>
</action>
</package>
