Class ChainingInterceptor

java.lang.Object
org.apache.struts2.interceptor.AbstractInterceptor
org.apache.struts2.interceptor.ChainingInterceptor
All Implemented Interfaces:
Serializable, ConditionalInterceptor, Interceptor

public class ChainingInterceptor extends AbstractInterceptor

An interceptor that copies all the properties of every object in the value stack to the currently executing object, except for any object that implements Unchainable. 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 ReflectionProvider.copy(Object, Object, java.util.Map, java.util.Collection, java.util.Collection) for more information.

Note: 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.

Note: By default Errors, Field errors and Message aren't copied during chaining, to change the behaviour you can specify the below three constants in struts.properties or struts.xml:

  • struts.chaining.copyErrors - set to true to copy Action Errors
  • struts.chaining.copyFieldErrors - set to true to copy Field Errors
  • struts.chaining.copyMessages - set to true to copy Action Messages

Example:

 <constant name="struts.xwork.chaining.copyErrors" value="true"/>
 

Note: By default actionErrors and actionMessages are excluded when copping object's properties.

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>
 
Author:
mrdon, tm_jee ( tm_jee(at)yahoo.co.uk )
See Also:
  • Field Details

  • Constructor Details

    • ChainingInterceptor

      public ChainingInterceptor()
  • Method Details

    • setReflectionProvider

      public void setReflectionProvider(ReflectionProvider prov)
    • setCopyErrors

      public void setCopyErrors(String copyErrors)
    • setCopyFieldErrors

      public void setCopyFieldErrors(String copyFieldErrors)
    • setCopyMessages

      public void setCopyMessages(String copyMessages)
    • intercept

      public String intercept(ActionInvocation invocation) throws Exception
      Description copied from class: AbstractInterceptor
      Override to handle interception
      Specified by:
      intercept in interface Interceptor
      Specified by:
      intercept in class AbstractInterceptor
      Parameters:
      invocation - the action invocation
      Returns:
      the return code, either returned from ActionInvocation.invoke(), or from the interceptor itself.
      Throws:
      Exception - any system-level error, as defined in Action.execute().
    • getExcludes

      public Collection<String> getExcludes()
      Gets list of parameter names to exclude
      Returns:
      the exclude list
    • setExcludes

      public void setExcludes(String excludes)
      Sets the list of parameter names to exclude from copying (all others will be included).
      Parameters:
      excludes - the excludes list as comma separated String
    • setExcludesCollection

      public void setExcludesCollection(Collection<String> excludes)
      Sets the list of parameter names to exclude from copying (all others will be included).
      Parameters:
      excludes - the excludes list
    • getIncludes

      public Collection<String> getIncludes()
      Gets list of parameter names to include
      Returns:
      the include list
    • setIncludes

      public void setIncludes(String includes)
      Sets the list of parameter names to include when copying (all others will be excluded).
      Parameters:
      includes - the includes list as comma separated String
    • setIncludesCollection

      public void setIncludesCollection(Collection<String> includes)
      Sets the list of parameter names to include when copying (all others will be excluded).
      Parameters:
      includes - the includes list