ChainingInterceptor

An interceptor that copies all the properties of every object in the value stack to the currently executing object, except for any object that implementsUnchainable. A collection of optional includes and excludes may be provided to control how and which parameters are copied. Only includes or excludes may be specified. Specifying both results in undefined behavior. See the javadocs for OgnlUtil.copy(Object, Object, java.util.Map, java.util.Collection, java.util.Collection) for more information.

It is important to remember that this interceptor does nothing if there are no objects already on the stack. This means two things: One, you can safely apply it to all your actions without any worry of adverse affects. Two, it is up to you to ensure an object exists in the stack prior to invoking this action. The most typical way this is done is through the use of the chain result type, which combines with this interceptor to make up the action chaining feature.

Interceptor parameters:

• excludes (optional) - the list of parameter names to exclude from copying (all others will be included).
• includes (optional) - the list of parameter names to include when copying (all others will be excluded).

Extending the interceptor:

There are no known extension points to this interceptor.

Example code:

 
 
 <action name="someAction" class="com.examples.SomeAction">
     <interceptor-ref name="basicStack"/>
     <result name="success" type="chain">otherAction</result>
 </action>

 <action name="otherAction" class="com.examples.OtherAction">
     <interceptor-ref name="chain"/>
     <interceptor-ref name="basicStack"/>
     <result name="success">good_result.ftl</result>
 </action>
 
该迭代器的作用是把value stack里面对象的属性拷贝到自己的action