001/* 002 * Copyright 2002-2018 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.resource; 018 019import java.io.IOException; 020 021import javax.servlet.http.HttpServletRequest; 022 023import org.springframework.core.io.Resource; 024 025/** 026 * A contract for invoking a chain of {@link ResourceTransformer ResourceTransformers} where each resolver 027 * is given a reference to the chain allowing it to delegate when necessary. 028 * 029 * @author Rossen Stoyanchev 030 * @since 4.1 031 */ 032public interface ResourceTransformerChain { 033 034 /** 035 * Return the {@code ResourceResolverChain} that was used to resolve the 036 * {@code Resource} being transformed. This may be needed for resolving 037 * related resources, e.g. links to other resources. 038 */ 039 ResourceResolverChain getResolverChain(); 040 041 /** 042 * Transform the given resource. 043 * @param request the current request 044 * @param resource the candidate resource to transform 045 * @return the transformed or the same resource, never {@code null} 046 * @throws IOException if transformation fails 047 */ 048 Resource transform(HttpServletRequest request, Resource resource) throws IOException; 049 050}