org.springframework.web.socket.adapter.AbstractWebSocketSession.java Source code

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Here is the source code for org.springframework.web.socket.adapter.AbstractWebSocketSession.java

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/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.socket.adapter;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.socket.BinaryMessage;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.PingMessage;
import org.springframework.web.socket.PongMessage;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;

/**
 * An abstract base class for implementations of {@link WebSocketSession}.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public abstract class AbstractWebSocketSession<T> implements NativeWebSocketSession {

    protected static final Log logger = LogFactory.getLog(NativeWebSocketSession.class);

    private final Map<String, Object> attributes = new ConcurrentHashMap<>();

    @Nullable
    private T nativeSession;

    /**
     * Create a new instance and associate the given attributes with it.
     * @param attributes attributes from the HTTP handshake to associate with the WebSocket
     * session; the provided attributes are copied, the original map is not used.
     */
    public AbstractWebSocketSession(@Nullable Map<String, Object> attributes) {
        if (attributes != null) {
            this.attributes.putAll(attributes);
        }
    }

    @Override
    public Map<String, Object> getAttributes() {
        return this.attributes;
    }

    @Override
    public T getNativeSession() {
        Assert.state(this.nativeSession != null, "WebSocket session not yet initialized");
        return this.nativeSession;
    }

    @SuppressWarnings("unchecked")
    @Override
    @Nullable
    public <R> R getNativeSession(@Nullable Class<R> requiredType) {
        return (requiredType == null || requiredType.isInstance(this.nativeSession) ? (R) this.nativeSession
                : null);
    }

    public void initializeNativeSession(T session) {
        Assert.notNull(session, "WebSocket session must not be null");
        this.nativeSession = session;
    }

    protected final void checkNativeSessionInitialized() {
        Assert.state(this.nativeSession != null, "WebSocket session is not yet initialized");
    }

    @Override
    public final void sendMessage(WebSocketMessage<?> message) throws IOException {
        checkNativeSessionInitialized();

        if (logger.isTraceEnabled()) {
            logger.trace("Sending " + message + ", " + this);
        }

        if (message instanceof TextMessage) {
            sendTextMessage((TextMessage) message);
        } else if (message instanceof BinaryMessage) {
            sendBinaryMessage((BinaryMessage) message);
        } else if (message instanceof PingMessage) {
            sendPingMessage((PingMessage) message);
        } else if (message instanceof PongMessage) {
            sendPongMessage((PongMessage) message);
        } else {
            throw new IllegalStateException("Unexpected WebSocketMessage type: " + message);
        }
    }

    protected abstract void sendTextMessage(TextMessage message) throws IOException;

    protected abstract void sendBinaryMessage(BinaryMessage message) throws IOException;

    protected abstract void sendPingMessage(PingMessage message) throws IOException;

    protected abstract void sendPongMessage(PongMessage message) throws IOException;

    @Override
    public final void close() throws IOException {
        close(CloseStatus.NORMAL);
    }

    @Override
    public final void close(CloseStatus status) throws IOException {
        checkNativeSessionInitialized();
        if (logger.isDebugEnabled()) {
            logger.debug("Closing " + this);
        }
        closeInternal(status);
    }

    protected abstract void closeInternal(CloseStatus status) throws IOException;

    @Override
    public String toString() {
        if (this.nativeSession != null) {
            return getClass().getSimpleName() + "[id=" + getId() + ", uri=" + getUri() + "]";
        } else {
            return getClass().getSimpleName() + "[nativeSession=null]";
        }
    }

}