001/* 002 * Copyright 2002-2016 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.socket.server.standard; 018 019import java.util.Arrays; 020import java.util.Map; 021import java.util.concurrent.ConcurrentHashMap; 022import javax.websocket.server.ServerEndpoint; 023import javax.websocket.server.ServerEndpointConfig.Configurator; 024 025import org.apache.commons.logging.Log; 026import org.apache.commons.logging.LogFactory; 027 028import org.springframework.core.annotation.AnnotationUtils; 029import org.springframework.stereotype.Component; 030import org.springframework.util.ClassUtils; 031import org.springframework.util.ObjectUtils; 032import org.springframework.web.context.ContextLoader; 033import org.springframework.web.context.WebApplicationContext; 034 035/** 036 * A {@link javax.websocket.server.ServerEndpointConfig.Configurator} for initializing 037 * {@link ServerEndpoint}-annotated classes through Spring. 038 * 039 * <p> 040 * <pre class="code"> 041 * @ServerEndpoint(value = "/echo", configurator = SpringConfigurator.class) 042 * public class EchoEndpoint { 043 * // ... 044 * } 045 * </pre> 046 * 047 * @author Rossen Stoyanchev 048 * @since 4.0 049 * @see ServerEndpointExporter 050 */ 051public class SpringConfigurator extends Configurator { 052 053 private static final String NO_VALUE = ObjectUtils.identityToString(new Object()); 054 055 private static final Log logger = LogFactory.getLog(SpringConfigurator.class); 056 057 private static final Map<String, Map<Class<?>, String>> cache = 058 new ConcurrentHashMap<String, Map<Class<?>, String>>(); 059 060 061 @SuppressWarnings("unchecked") 062 @Override 063 public <T> T getEndpointInstance(Class<T> endpointClass) throws InstantiationException { 064 WebApplicationContext wac = ContextLoader.getCurrentWebApplicationContext(); 065 if (wac == null) { 066 String message = "Failed to find the root WebApplicationContext. Was ContextLoaderListener not used?"; 067 logger.error(message); 068 throw new IllegalStateException(message); 069 } 070 071 String beanName = ClassUtils.getShortNameAsProperty(endpointClass); 072 if (wac.containsBean(beanName)) { 073 T endpoint = wac.getBean(beanName, endpointClass); 074 if (logger.isTraceEnabled()) { 075 logger.trace("Using @ServerEndpoint singleton " + endpoint); 076 } 077 return endpoint; 078 } 079 080 Component ann = AnnotationUtils.findAnnotation(endpointClass, Component.class); 081 if (ann != null && wac.containsBean(ann.value())) { 082 T endpoint = wac.getBean(ann.value(), endpointClass); 083 if (logger.isTraceEnabled()) { 084 logger.trace("Using @ServerEndpoint singleton " + endpoint); 085 } 086 return endpoint; 087 } 088 089 beanName = getBeanNameByType(wac, endpointClass); 090 if (beanName != null) { 091 return (T) wac.getBean(beanName); 092 } 093 094 if (logger.isTraceEnabled()) { 095 logger.trace("Creating new @ServerEndpoint instance of type " + endpointClass); 096 } 097 return wac.getAutowireCapableBeanFactory().createBean(endpointClass); 098 } 099 100 private String getBeanNameByType(WebApplicationContext wac, Class<?> endpointClass) { 101 String wacId = wac.getId(); 102 103 Map<Class<?>, String> beanNamesByType = cache.get(wacId); 104 if (beanNamesByType == null) { 105 beanNamesByType = new ConcurrentHashMap<Class<?>, String>(); 106 cache.put(wacId, beanNamesByType); 107 } 108 109 if (!beanNamesByType.containsKey(endpointClass)) { 110 String[] names = wac.getBeanNamesForType(endpointClass); 111 if (names.length == 1) { 112 beanNamesByType.put(endpointClass, names[0]); 113 } 114 else { 115 beanNamesByType.put(endpointClass, NO_VALUE); 116 if (names.length > 1) { 117 throw new IllegalStateException("Found multiple @ServerEndpoint's of type [" + 118 endpointClass.getName() + "]: bean names " + Arrays.asList(names)); 119 } 120 } 121 } 122 123 String beanName = beanNamesByType.get(endpointClass); 124 return (NO_VALUE.equals(beanName) ? null : beanName); 125 } 126 127}