001/* 002 * Copyright 2002-2012 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 javax.servlet.ServletContext; 020 021import org.apache.commons.logging.Log; 022import org.apache.commons.logging.LogFactory; 023 024import org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor; 025import org.springframework.util.Assert; 026import org.springframework.util.ClassUtils; 027import org.springframework.web.context.ContextLoader; 028import org.springframework.web.context.WebApplicationContext; 029 030/** 031 * Convenient base class for self-autowiring classes that gets constructed 032 * within a Spring-based web application. Resolves {@code @Autowired} 033 * annotations in the endpoint class against beans in the current Spring 034 * root web application context (as determined by the current thread's 035 * context ClassLoader, which needs to be the web application's ClassLoader). 036 * Can alternatively be used as a delegate instead of as a base class. 037 * 038 * <p>A typical usage of this base class is a JAX-WS endpoint class: 039 * Such a Spring-based JAX-WS endpoint implementation will follow the 040 * standard JAX-WS contract for endpoint classes but will be 'thin' 041 * in that it delegates the actual work to one or more Spring-managed 042 * service beans - typically obtained using {@code @Autowired}. 043 * The lifecycle of such an endpoint instance will be managed by the 044 * JAX-WS runtime, hence the need for this base class to provide 045 * {@code @Autowired} processing based on the current Spring context. 046 * 047 * <p><b>NOTE:</b> If there is an explicit way to access the ServletContext, 048 * prefer such a way over using this class. The {@link WebApplicationContextUtils} 049 * class allows for easy access to the Spring root web application context 050 * based on the ServletContext. 051 * 052 * @author Juergen Hoeller 053 * @since 2.5.1 054 * @see WebApplicationObjectSupport 055 */ 056public abstract class SpringBeanAutowiringSupport { 057 058 private static final Log logger = LogFactory.getLog(SpringBeanAutowiringSupport.class); 059 060 061 /** 062 * This constructor performs injection on this instance, 063 * based on the current web application context. 064 * <p>Intended for use as a base class. 065 * @see #processInjectionBasedOnCurrentContext 066 */ 067 public SpringBeanAutowiringSupport() { 068 processInjectionBasedOnCurrentContext(this); 069 } 070 071 072 /** 073 * Process {@code @Autowired} injection for the given target object, 074 * based on the current web application context. 075 * <p>Intended for use as a delegate. 076 * @param target the target object to process 077 * @see org.springframework.web.context.ContextLoader#getCurrentWebApplicationContext() 078 */ 079 public static void processInjectionBasedOnCurrentContext(Object target) { 080 Assert.notNull(target, "Target object must not be null"); 081 WebApplicationContext cc = ContextLoader.getCurrentWebApplicationContext(); 082 if (cc != null) { 083 AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor(); 084 bpp.setBeanFactory(cc.getAutowireCapableBeanFactory()); 085 bpp.processInjection(target); 086 } 087 else { 088 if (logger.isDebugEnabled()) { 089 logger.debug("Current WebApplicationContext is not available for processing of " + 090 ClassUtils.getShortName(target.getClass()) + ": " + 091 "Make sure this class gets constructed in a Spring web application. Proceeding without injection."); 092 } 093 } 094 } 095 096 097 /** 098 * Process {@code @Autowired} injection for the given target object, 099 * based on the current root web application context as stored in the ServletContext. 100 * <p>Intended for use as a delegate. 101 * @param target the target object to process 102 * @param servletContext the ServletContext to find the Spring web application context in 103 * @see WebApplicationContextUtils#getWebApplicationContext(javax.servlet.ServletContext) 104 */ 105 public static void processInjectionBasedOnServletContext(Object target, ServletContext servletContext) { 106 Assert.notNull(target, "Target object must not be null"); 107 WebApplicationContext cc = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext); 108 AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor(); 109 bpp.setBeanFactory(cc.getAutowireCapableBeanFactory()); 110 bpp.processInjection(target); 111 } 112 113}