/* * Copyright 2002-2013 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 * * https://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.servlet.support;import java.util.Map;import javax.servlet.http.HttpServletRequest;/** * A contract for inspecting and potentially modifying request data values such * as URL query parameters or form field values before they are rendered by a * view or before a redirect. * * <p>Implementations may use this contract for example as part of a solution * to provide data integrity, confidentiality, protection against cross-site * request forgery (CSRF), and others or for other tasks such as automatically * adding a hidden field to all forms and URLs. * * <p>View technologies that support this contract can obtain an instance to * delegate to via {@link RequestContext#getRequestDataValueProcessor()}. * * @author Rossen Stoyanchev * @since 3.1 */public interface RequestDataValueProcessor { /** * Invoked when a new form action is rendered. * @param request the current request * @param action the form action * @param httpMethod the form HTTP method * @return the action to use, possibly modified */ String processAction(HttpServletRequest request, String action, String httpMethod); /** * Invoked when a form field value is rendered. * @param request the current request * @param name the form field name * @param value the form field value * @param type the form field type ("text", "hidden", etc.) * @return the form field value to use, possibly modified */ String processFormFieldValue(HttpServletRequest request, String name, String value, String type); /** * Invoked after all form fields have been rendered. * @param request the current request * @return additional hidden form fields to be added, or {@code null} */ Map<String, String> getExtraHiddenFields(HttpServletRequest request); /** * Invoked when a URL is about to be rendered or redirected to. * @param request the current request * @param url the URL value * @return the URL to use, possibly modified */ String processUrl(HttpServletRequest request, String url);}