ParameterMappingInterceptor (Spring Framework 4.3.30.RELEASE API)

java.lang.Object
- org.springframework.web.portlet.handler.HandlerInterceptorAdapter
- - org.springframework.web.portlet.handler.ParameterMappingInterceptor

All Implemented Interfaces:
HandlerInterceptor
```
public class ParameterMappingInterceptor
extends HandlerInterceptorAdapter
```
Interceptor to forward a request parameter from the ActionRequest to the RenderRequest.
This can be useful when using ParameterHandlerMapping or PortletModeParameterHandlerMapping. It will ensure that the parameter that was used to map the ActionRequest to a handler will be forwarded to the RenderRequest so that it will also be mapped the same way.
When using this Interceptor, you can still change the value of the mapping parameter in your handler in order to change where the render request will get mapped.
Be aware that this Interceptor does call ActionResponse.setRenderParameter, which means that you will not be able to call ActionResponse.sendRedirect in your handler. If you may need to issue a redirect, then you should avoid this Interceptor and either write a different one that does this in a different way, or manually forward the parameter from within your handler(s).
Thanks to Rainer Schmitz for suggesting this mapping strategy!
Since:
2.0
Author:
John A. Lewis
See Also:
ParameterHandlerMapping, PortletModeParameterHandlerMapping

Field Summary
Fields
Modifier and Type Field Description
static String DEFAULT_PARAMETER_NAME
Request parameter name to use for mapping to handlers

Constructor Summary
Constructors
Constructor Description
ParameterMappingInterceptor()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`preHandleAction(ActionRequest request, ActionResponse response, Object handler)`	If request is an `ActionRequest`, get handler mapping parameter and add it to the ActionResponse.
`void`	`setParameterName(String parameterName)`	Set the name of the parameter used for mapping.

Methods inherited from class org.springframework.web.portlet.handler.HandlerInterceptorAdapter
afterActionCompletion, afterCompletion, afterEventCompletion, afterRenderCompletion, afterResourceCompletion, postHandleRender, postHandleResource, preHandle, preHandleEvent, preHandleRender, preHandleResource

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_PARAMETER_NAME
```
public static final String DEFAULT_PARAMETER_NAME
```
    Request parameter name to use for mapping to handlers
    See Also:
    Constant Field Values
- Constructor Detail
  - ParameterMappingInterceptor
```
public ParameterMappingInterceptor()
```
- Method Detail
  - setParameterName
```
public void setParameterName(String parameterName)
```
    Set the name of the parameter used for mapping.
  - preHandleAction
```
public boolean preHandleAction(ActionRequest request,
                               ActionResponse response,
                               Object handler)
```
    If request is an ActionRequest, get handler mapping parameter and add it to the ActionResponse.
    Specified by:
    preHandleAction in interface HandlerInterceptor
    Overrides:
    preHandleAction in class HandlerInterceptorAdapter
    Parameters:
    request - current portlet action request
    response - current portlet action response
    handler - chosen handler to execute, for type and/or instance evaluation
    Returns:
    true if the execution chain should proceed with the next interceptor or the handler itself. Else, DispatcherPortlet assumes that this interceptor has already dealt with the response itself