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.context.support; 018 019import java.util.HashSet; 020import java.util.Set; 021 022import javax.servlet.http.HttpServletRequest; 023import javax.servlet.http.HttpServletRequestWrapper; 024 025import org.springframework.lang.Nullable; 026import org.springframework.util.Assert; 027import org.springframework.web.context.WebApplicationContext; 028 029/** 030 * HttpServletRequest decorator that makes all Spring beans in a 031 * given WebApplicationContext accessible as request attributes, 032 * through lazy checking once an attribute gets accessed. 033 * 034 * @author Juergen Hoeller 035 * @since 2.5 036 */ 037public class ContextExposingHttpServletRequest extends HttpServletRequestWrapper { 038 039 private final WebApplicationContext webApplicationContext; 040 041 @Nullable 042 private final Set<String> exposedContextBeanNames; 043 044 @Nullable 045 private Set<String> explicitAttributes; 046 047 048 /** 049 * Create a new ContextExposingHttpServletRequest for the given request. 050 * @param originalRequest the original HttpServletRequest 051 * @param context the WebApplicationContext that this request runs in 052 */ 053 public ContextExposingHttpServletRequest(HttpServletRequest originalRequest, WebApplicationContext context) { 054 this(originalRequest, context, null); 055 } 056 057 /** 058 * Create a new ContextExposingHttpServletRequest for the given request. 059 * @param originalRequest the original HttpServletRequest 060 * @param context the WebApplicationContext that this request runs in 061 * @param exposedContextBeanNames the names of beans in the context which 062 * are supposed to be exposed (if this is non-null, only the beans in this 063 * Set are eligible for exposure as attributes) 064 */ 065 public ContextExposingHttpServletRequest(HttpServletRequest originalRequest, WebApplicationContext context, 066 @Nullable Set<String> exposedContextBeanNames) { 067 068 super(originalRequest); 069 Assert.notNull(context, "WebApplicationContext must not be null"); 070 this.webApplicationContext = context; 071 this.exposedContextBeanNames = exposedContextBeanNames; 072 } 073 074 075 /** 076 * Return the WebApplicationContext that this request runs in. 077 */ 078 public final WebApplicationContext getWebApplicationContext() { 079 return this.webApplicationContext; 080 } 081 082 083 @Override 084 @Nullable 085 public Object getAttribute(String name) { 086 if ((this.explicitAttributes == null || !this.explicitAttributes.contains(name)) && 087 (this.exposedContextBeanNames == null || this.exposedContextBeanNames.contains(name)) && 088 this.webApplicationContext.containsBean(name)) { 089 return this.webApplicationContext.getBean(name); 090 } 091 else { 092 return super.getAttribute(name); 093 } 094 } 095 096 @Override 097 public void setAttribute(String name, Object value) { 098 super.setAttribute(name, value); 099 if (this.explicitAttributes == null) { 100 this.explicitAttributes = new HashSet<>(8); 101 } 102 this.explicitAttributes.add(name); 103 } 104 105}