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.messaging.simp; 018 019import org.springframework.beans.factory.ObjectFactory; 020import org.springframework.beans.factory.config.Scope; 021import org.springframework.lang.Nullable; 022 023/** 024 * A {@link Scope} implementation exposing the attributes of a SiMP session 025 * (e.g. WebSocket session). 026 * 027 * <p>Relies on a thread-bound {@link SimpAttributes} instance exported by 028 * {@link org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler}. 029 * 030 * @author Rossen Stoyanchev 031 * @since 4.1 032 */ 033public class SimpSessionScope implements Scope { 034 035 @Override 036 public Object get(String name, ObjectFactory<?> objectFactory) { 037 SimpAttributes simpAttributes = SimpAttributesContextHolder.currentAttributes(); 038 Object scopedObject = simpAttributes.getAttribute(name); 039 if (scopedObject != null) { 040 return scopedObject; 041 } 042 synchronized (simpAttributes.getSessionMutex()) { 043 scopedObject = simpAttributes.getAttribute(name); 044 if (scopedObject == null) { 045 scopedObject = objectFactory.getObject(); 046 simpAttributes.setAttribute(name, scopedObject); 047 } 048 return scopedObject; 049 } 050 } 051 052 @Override 053 @Nullable 054 public Object remove(String name) { 055 SimpAttributes simpAttributes = SimpAttributesContextHolder.currentAttributes(); 056 synchronized (simpAttributes.getSessionMutex()) { 057 Object value = simpAttributes.getAttribute(name); 058 if (value != null) { 059 simpAttributes.removeAttribute(name); 060 return value; 061 } 062 else { 063 return null; 064 } 065 } 066 } 067 068 @Override 069 public void registerDestructionCallback(String name, Runnable callback) { 070 SimpAttributesContextHolder.currentAttributes().registerDestructionCallback(name, callback); 071 } 072 073 @Override 074 @Nullable 075 public Object resolveContextualObject(String key) { 076 return null; 077 } 078 079 @Override 080 public String getConversationId() { 081 return SimpAttributesContextHolder.currentAttributes().getSessionId(); 082 } 083 084}