001/* 002 * Copyright 2002-2017 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.method.annotation; 018 019import org.springframework.core.MethodParameter; 020import org.springframework.lang.Nullable; 021import org.springframework.util.PatternMatchUtils; 022import org.springframework.web.context.request.NativeWebRequest; 023import org.springframework.web.method.support.HandlerMethodReturnValueHandler; 024import org.springframework.web.method.support.ModelAndViewContainer; 025import org.springframework.web.servlet.ModelAndView; 026import org.springframework.web.servlet.SmartView; 027import org.springframework.web.servlet.View; 028 029/** 030 * Handles return values of type {@link ModelAndView} copying view and model 031 * information to the {@link ModelAndViewContainer}. 032 * 033 * <p>If the return value is {@code null}, the 034 * {@link ModelAndViewContainer#setRequestHandled(boolean)} flag is set to 035 * {@code true} to indicate the request was handled directly. 036 * 037 * <p>A {@link ModelAndView} return type has a set purpose. Therefore this 038 * handler should be configured ahead of handlers that support any return 039 * value type annotated with {@code @ModelAttribute} or {@code @ResponseBody} 040 * to ensure they don't take over. 041 * 042 * @author Rossen Stoyanchev 043 * @since 3.1 044 */ 045public class ModelAndViewMethodReturnValueHandler implements HandlerMethodReturnValueHandler { 046 047 @Nullable 048 private String[] redirectPatterns; 049 050 051 /** 052 * Configure one more simple patterns (as described in {@link PatternMatchUtils#simpleMatch}) 053 * to use in order to recognize custom redirect prefixes in addition to "redirect:". 054 * <p>Note that simply configuring this property will not make a custom redirect prefix work. 055 * There must be a custom {@link View} that recognizes the prefix as well. 056 * @since 4.1 057 */ 058 public void setRedirectPatterns(@Nullable String... redirectPatterns) { 059 this.redirectPatterns = redirectPatterns; 060 } 061 062 /** 063 * Return the configured redirect patterns, if any. 064 * @since 4.1 065 */ 066 @Nullable 067 public String[] getRedirectPatterns() { 068 return this.redirectPatterns; 069 } 070 071 072 @Override 073 public boolean supportsReturnType(MethodParameter returnType) { 074 return ModelAndView.class.isAssignableFrom(returnType.getParameterType()); 075 } 076 077 @Override 078 public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType, 079 ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception { 080 081 if (returnValue == null) { 082 mavContainer.setRequestHandled(true); 083 return; 084 } 085 086 ModelAndView mav = (ModelAndView) returnValue; 087 if (mav.isReference()) { 088 String viewName = mav.getViewName(); 089 mavContainer.setViewName(viewName); 090 if (viewName != null && isRedirectViewName(viewName)) { 091 mavContainer.setRedirectModelScenario(true); 092 } 093 } 094 else { 095 View view = mav.getView(); 096 mavContainer.setView(view); 097 if (view instanceof SmartView && ((SmartView) view).isRedirectView()) { 098 mavContainer.setRedirectModelScenario(true); 099 } 100 } 101 mavContainer.setStatus(mav.getStatus()); 102 mavContainer.addAllAttributes(mav.getModel()); 103 } 104 105 /** 106 * Whether the given view name is a redirect view reference. 107 * The default implementation checks the configured redirect patterns and 108 * also if the view name starts with the "redirect:" prefix. 109 * @param viewName the view name to check, never {@code null} 110 * @return "true" if the given view name is recognized as a redirect view 111 * reference; "false" otherwise. 112 */ 113 protected boolean isRedirectViewName(String viewName) { 114 return (PatternMatchUtils.simpleMatch(this.redirectPatterns, viewName) || viewName.startsWith("redirect:")); 115 } 116 117}