001/* 002 * Copyright 2002-2016 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.servlet.mvc.condition; 018 019import javax.servlet.http.HttpServletRequest; 020 021/** 022 * Contract for request mapping conditions. 023 * 024 * <p>Request conditions can be combined via {@link #combine(Object)}, matched to 025 * a request via {@link #getMatchingCondition(HttpServletRequest)}, and compared 026 * to each other via {@link #compareTo(Object, HttpServletRequest)} to determine 027 * which is a closer match for a given request. 028 * 029 * @author Rossen Stoyanchev 030 * @author Arjen Poutsma 031 * @since 3.1 032 * @param <T> the type of objects that this RequestCondition can be combined 033 * with and compared to 034 */ 035public interface RequestCondition<T> { 036 037 /** 038 * Combine this condition with another such as conditions from a 039 * type-level and method-level {@code @RequestMapping} annotation. 040 * @param other the condition to combine with. 041 * @return a request condition instance that is the result of combining 042 * the two condition instances. 043 */ 044 T combine(T other); 045 046 /** 047 * Check if the condition matches the request returning a potentially new 048 * instance created for the current request. For example a condition with 049 * multiple URL patterns may return a new instance only with those patterns 050 * that match the request. 051 * <p>For CORS pre-flight requests, conditions should match to the would-be, 052 * actual request (e.g. URL pattern, query parameters, and the HTTP method 053 * from the "Access-Control-Request-Method" header). If a condition cannot 054 * be matched to a pre-flight request it should return an instance with 055 * empty content thus not causing a failure to match. 056 * @return a condition instance in case of a match or {@code null} otherwise. 057 */ 058 T getMatchingCondition(HttpServletRequest request); 059 060 /** 061 * Compare this condition to another condition in the context of 062 * a specific request. This method assumes both instances have 063 * been obtained via {@link #getMatchingCondition(HttpServletRequest)} 064 * to ensure they have content relevant to current request only. 065 */ 066 int compareTo(T other, HttpServletRequest request); 067 068}