Spring Framework example source code file (ParameterMappingInterceptor.java)

This example Spring Framework source code file (ParameterMappingInterceptor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

actionresponse, actionresponse, default_parameter_name, default_parameter_name, handlerinterceptoradapter, object, object, parametermappinginterceptor, string, string

The Spring Framework ParameterMappingInterceptor.java source code

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.portlet.handler;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;

/**
 * Interceptor to forward a request parameter from the <code>ActionRequest to the
 * <code>RenderRequest.
 *
 * <p>This can be useful when using {@link ParameterHandlerMapping ParameterHandlerMapping}
 * or {@link PortletModeParameterHandlerMapping PortletModeParameterHandlerMapping}.
 * It will ensure that the parameter that was used to map the <code>ActionRequest
 * to a handler will be forwarded to the <code>RenderRequest so that it will also be 
 * mapped the same way.
 *
 * <p>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.
 *
 * <p>Be aware that this Interceptor does call ActionResponse.setRenderParameter,
 * which means that you will not be able to call <code>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).
 *
 * <p>Thanks to Rainer Schmitz for suggesting this mapping strategy!
 *
 * @author John A. Lewis
 * @since 2.0
 * @see ParameterHandlerMapping
 * @see PortletModeParameterHandlerMapping
 */
public class ParameterMappingInterceptor extends HandlerInterceptorAdapter {

	/** Request parameter name to use for mapping to handlers */
	public final static String DEFAULT_PARAMETER_NAME = "action";

	private String parameterName = DEFAULT_PARAMETER_NAME;


	/**
	 * Set the name of the parameter used for mapping.
	 */
	public void setParameterName(String parameterName) {
		this.parameterName = (parameterName != null ? parameterName : DEFAULT_PARAMETER_NAME);
	}


	/**
	 * If request is an {@link javax.portlet.ActionRequest ActionRequest},
	 * get handler mapping parameter and add it to the ActionResponse.
	 */
	public boolean preHandleAction(ActionRequest request, ActionResponse response, Object handler) {
		String mappingParameter = request.getParameter(this.parameterName);
		if (mappingParameter != null) {
			response.setRenderParameter(parameterName, mappingParameter);
		}
		return true;
	}

}