001/*
002 * Copyright 2002-2018 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.lang.Nullable;
027import org.springframework.util.AlternativeJdkIdGenerator;
028import org.springframework.util.Assert;
029import org.springframework.util.IdGenerator;
030import org.springframework.web.socket.BinaryMessage;
031import org.springframework.web.socket.CloseStatus;
032import org.springframework.web.socket.PingMessage;
033import org.springframework.web.socket.PongMessage;
034import org.springframework.web.socket.TextMessage;
035import org.springframework.web.socket.WebSocketMessage;
036import org.springframework.web.socket.WebSocketSession;
037
038/**
039 * An abstract base class for implementations of {@link WebSocketSession}.
040 *
041 * @author Rossen Stoyanchev
042 * @since 4.0
043 * @param <T> the native session type
044 */
045public abstract class AbstractWebSocketSession<T> implements NativeWebSocketSession {
046
047        protected static final IdGenerator idGenerator = new AlternativeJdkIdGenerator();
048
049        protected static final Log logger = LogFactory.getLog(NativeWebSocketSession.class);
050
051
052        private final Map<String, Object> attributes = new ConcurrentHashMap<>();
053
054        @Nullable
055        private T nativeSession;
056
057
058        /**
059         * Create a new instance and associate the given attributes with it.
060         * @param attributes the attributes from the HTTP handshake to associate with the WebSocket
061         * session; the provided attributes are copied, the original map is not used.
062         */
063        public AbstractWebSocketSession(@Nullable Map<String, Object> attributes) {
064                if (attributes != null) {
065                        this.attributes.putAll(attributes);
066                }
067        }
068
069
070        @Override
071        public Map<String, Object> getAttributes() {
072                return this.attributes;
073        }
074
075        @Override
076        public T getNativeSession() {
077                Assert.state(this.nativeSession != null, "WebSocket session not yet initialized");
078                return this.nativeSession;
079        }
080
081        @SuppressWarnings("unchecked")
082        @Override
083        @Nullable
084        public <R> R getNativeSession(@Nullable Class<R> requiredType) {
085                return (requiredType == null || requiredType.isInstance(this.nativeSession) ? (R) this.nativeSession : null);
086        }
087
088        public void initializeNativeSession(T session) {
089                Assert.notNull(session, "WebSocket session must not be null");
090                this.nativeSession = session;
091        }
092
093        protected final void checkNativeSessionInitialized() {
094                Assert.state(this.nativeSession != null, "WebSocket session is not yet initialized");
095        }
096
097        @Override
098        public final void sendMessage(WebSocketMessage<?> message) throws IOException {
099                checkNativeSessionInitialized();
100
101                if (logger.isTraceEnabled()) {
102                        logger.trace("Sending " + message + ", " + this);
103                }
104
105                if (message instanceof TextMessage) {
106                        sendTextMessage((TextMessage) message);
107                }
108                else if (message instanceof BinaryMessage) {
109                        sendBinaryMessage((BinaryMessage) message);
110                }
111                else if (message instanceof PingMessage) {
112                        sendPingMessage((PingMessage) message);
113                }
114                else if (message instanceof PongMessage) {
115                        sendPongMessage((PongMessage) message);
116                }
117                else {
118                        throw new IllegalStateException("Unexpected WebSocketMessage type: " + message);
119                }
120        }
121
122        protected abstract void sendTextMessage(TextMessage message) throws IOException;
123
124        protected abstract void sendBinaryMessage(BinaryMessage message) throws IOException;
125
126        protected abstract void sendPingMessage(PingMessage message) throws IOException;
127
128        protected abstract void sendPongMessage(PongMessage message) throws IOException;
129
130
131        @Override
132        public final void close() throws IOException {
133                close(CloseStatus.NORMAL);
134        }
135
136        @Override
137        public final void close(CloseStatus status) throws IOException {
138                checkNativeSessionInitialized();
139                if (logger.isDebugEnabled()) {
140                        logger.debug("Closing " + this);
141                }
142                closeInternal(status);
143        }
144
145        protected abstract void closeInternal(CloseStatus status) throws IOException;
146
147
148        @Override
149        public String toString() {
150                if (this.nativeSession != null) {
151                        return getClass().getSimpleName() + "[id=" + getId() + ", uri=" + getUri() + "]";
152                }
153                else {
154                        return getClass().getSimpleName() + "[nativeSession=null]";
155                }
156        }
157
158}