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.socket.adapter;
018
019import java.io.IOException;
020import java.util.Map;
021import java.util.concurrent.ConcurrentHashMap;
022
023import org.apache.commons.logging.Log;
024import org.apache.commons.logging.LogFactory;
025
026import org.springframework.util.Assert;
027import org.springframework.web.socket.BinaryMessage;
028import org.springframework.web.socket.CloseStatus;
029import org.springframework.web.socket.PingMessage;
030import org.springframework.web.socket.PongMessage;
031import org.springframework.web.socket.TextMessage;
032import org.springframework.web.socket.WebSocketMessage;
033import org.springframework.web.socket.WebSocketSession;
034
035/**
036 * An abstract base class for implementations of {@link WebSocketSession}.
037 *
038 * @author Rossen Stoyanchev
039 * @since 4.0
040 */
041public abstract class AbstractWebSocketSession<T> implements NativeWebSocketSession {
042
043        protected static final Log logger = LogFactory.getLog(NativeWebSocketSession.class);
044
045        private final Map<String, Object> attributes = new ConcurrentHashMap<String, Object>();
046
047        private T nativeSession;
048
049
050        /**
051         * Create a new instance and associate the given attributes with it.
052         * @param attributes attributes from the HTTP handshake to associate with the WebSocket
053         * session; the provided attributes are copied, the original map is not used.
054         */
055        public AbstractWebSocketSession(Map<String, Object> attributes) {
056                if (attributes != null) {
057                        this.attributes.putAll(attributes);
058                }
059        }
060
061
062        @Override
063        public Map<String, Object> getAttributes() {
064                return this.attributes;
065        }
066
067        @Override
068        public T getNativeSession() {
069                return this.nativeSession;
070        }
071
072        @SuppressWarnings("unchecked")
073        @Override
074        public <R> R getNativeSession(Class<R> requiredType) {
075                if (requiredType != null) {
076                        if (requiredType.isInstance(this.nativeSession)) {
077                                return (R) this.nativeSession;
078                        }
079                }
080                return null;
081        }
082
083        public void initializeNativeSession(T session) {
084                Assert.notNull(session, "WebSocket session must not be null");
085                this.nativeSession = session;
086        }
087
088        protected final void checkNativeSessionInitialized() {
089                Assert.state(this.nativeSession != null, "WebSocket session is not yet initialized");
090        }
091
092        @Override
093        public final void sendMessage(WebSocketMessage<?> message) throws IOException {
094                checkNativeSessionInitialized();
095
096                if (logger.isTraceEnabled()) {
097                        logger.trace("Sending " + message + ", " + this);
098                }
099
100                if (message instanceof TextMessage) {
101                        sendTextMessage((TextMessage) message);
102                }
103                else if (message instanceof BinaryMessage) {
104                        sendBinaryMessage((BinaryMessage) message);
105                }
106                else if (message instanceof PingMessage) {
107                        sendPingMessage((PingMessage) message);
108                }
109                else if (message instanceof PongMessage) {
110                        sendPongMessage((PongMessage) message);
111                }
112                else {
113                        throw new IllegalStateException("Unexpected WebSocketMessage type: " + message);
114                }
115        }
116
117        protected abstract void sendTextMessage(TextMessage message) throws IOException;
118
119        protected abstract void sendBinaryMessage(BinaryMessage message) throws IOException;
120
121        protected abstract void sendPingMessage(PingMessage message) throws IOException;
122
123        protected abstract void sendPongMessage(PongMessage message) throws IOException;
124
125
126        @Override
127        public final void close() throws IOException {
128                close(CloseStatus.NORMAL);
129        }
130
131        @Override
132        public final void close(CloseStatus status) throws IOException {
133                checkNativeSessionInitialized();
134                if (logger.isDebugEnabled()) {
135                        logger.debug("Closing " + this);
136                }
137                closeInternal(status);
138        }
139
140        protected abstract void closeInternal(CloseStatus status) throws IOException;
141
142
143        @Override
144        public String toString() {
145                if (this.nativeSession != null) {
146                        return getClass().getSimpleName() + "[id=" + getId() + ", uri=" + getUri() + "]";
147                }
148                else {
149                        return getClass().getSimpleName() + "[nativeSession=null]";
150                }
151        }
152
153}