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.filter;
018
019import java.io.IOException;
020
021import javax.servlet.FilterChain;
022import javax.servlet.ServletException;
023import javax.servlet.http.HttpServletRequest;
024import javax.servlet.http.HttpServletResponse;
025
026import org.springframework.http.HttpStatus;
027import org.springframework.util.Assert;
028
029/**
030 * Overrides {@link HttpServletResponse#sendRedirect(String)} and handles it by
031 * setting the HTTP status and "Location" headers, which keeps the Servlet
032 * container from re-writing relative redirect URLs into absolute ones.
033 * Servlet containers are required to do that but against the recommendation of
034 * <a href="https://tools.ietf.org/html/rfc7231#section-7.1.2"> RFC 7231 Section 7.1.2</a>,
035 * and furthermore not necessarily taking into account "X-Forwarded" headers.
036 *
037 * <p><strong>Note:</strong> While relative redirects are recommended in the
038 * RFC, under some configurations with reverse proxies they may not work.
039 *
040 * @author Rob Winch
041 * @author Rossen Stoyanchev
042 * @since 4.3.10
043 */
044public class RelativeRedirectFilter extends OncePerRequestFilter {
045
046        private HttpStatus redirectStatus = HttpStatus.SEE_OTHER;
047
048
049        /**
050         * Set the default HTTP Status to use for redirects.
051         * <p>By default this is {@link HttpStatus#SEE_OTHER}.
052         * @param status the 3xx redirect status to use
053         */
054        public void setRedirectStatus(HttpStatus status) {
055                Assert.notNull(status, "Property 'redirectStatus' is required");
056                Assert.isTrue(status.is3xxRedirection(), "Not a redirect status code");
057                this.redirectStatus = status;
058        }
059
060        /**
061         * Return the configured redirect status.
062         */
063        public HttpStatus getRedirectStatus() {
064                return this.redirectStatus;
065        }
066
067
068        @Override
069        protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
070                        FilterChain filterChain) throws ServletException, IOException {
071
072                response = RelativeRedirectResponseWrapper.wrapIfNecessary(response, this.redirectStatus);
073                filterChain.doFilter(request, response);
074        }
075
076}