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.core.NamedThreadLocal; 020import org.springframework.messaging.Message; 021 022/** 023 * Holder class to expose SiMP attributes associated with a session (e.g. WebSocket) 024 * in the form of a thread-bound {@link SimpAttributes} object. 025 * 026 * @author Rossen Stoyanchev 027 * @since 4.1 028 */ 029public abstract class SimpAttributesContextHolder { 030 031 private static final ThreadLocal<SimpAttributes> attributesHolder = 032 new NamedThreadLocal<SimpAttributes>("SiMP session attributes"); 033 034 035 /** 036 * Reset the SimpAttributes for the current thread. 037 */ 038 public static void resetAttributes() { 039 attributesHolder.remove(); 040 } 041 042 /** 043 * Bind the given SimpAttributes to the current thread, 044 * @param attributes the RequestAttributes to expose 045 */ 046 public static void setAttributes(SimpAttributes attributes) { 047 if (attributes != null) { 048 attributesHolder.set(attributes); 049 } 050 else { 051 resetAttributes(); 052 } 053 } 054 055 /** 056 * Extract the SiMP session attributes from the given message, wrap them in 057 * a {@link SimpAttributes} instance and bind it to the current thread, 058 * @param message the message to extract session attributes from 059 */ 060 public static void setAttributesFromMessage(Message<?> message) { 061 setAttributes(SimpAttributes.fromMessage(message)); 062 } 063 064 /** 065 * Return the SimpAttributes currently bound to the thread. 066 * @return the attributes or {@code null} if not bound 067 */ 068 public static SimpAttributes getAttributes() { 069 return attributesHolder.get(); 070 } 071 072 /** 073 * Return the SimpAttributes currently bound to the thread or raise an 074 * {@link java.lang.IllegalStateException} if none are bound.. 075 * @return the attributes, never {@code null} 076 * @throws java.lang.IllegalStateException if attributes are not bound 077 */ 078 public static SimpAttributes currentAttributes() throws IllegalStateException { 079 SimpAttributes attributes = getAttributes(); 080 if (attributes == null) { 081 throw new IllegalStateException("No thread-bound SimpAttributes found. " + 082 "Your code is probably not processing a client message and executing in " + 083 "message-handling methods invoked by the SimpAnnotationMethodMessageHandler?"); 084 } 085 return attributes; 086 } 087 088}