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

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

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/*
 *
 * 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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}.
 *
 * @param T the type of the native (or delegate) WebSocket session
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public abstract class AbstractWebSocketSesssion<T> implements WebSocketSession, NativeWebSocketSession {

    protected final Log logger = LogFactory.getLog(getClass());

    private T nativeSession;

    private final Map<String, Object> handshakeAttributes;

    /**
     * Class constructor
     *
     * @param handshakeAttributes attributes from the HTTP handshake to make available
     *        through the WebSocket session
     */
    public AbstractWebSocketSesssion(Map<String, Object> handshakeAttributes) {
        this.handshakeAttributes = handshakeAttributes;
    }

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

    @Override
    public T getNativeSession() {
        return this.nativeSession;
    }

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

    public void initializeNativeSession(T session) {
        Assert.notNull(session, "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();
        Assert.isTrue(isOpen(), "Cannot send message after connection closed.");

        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() {
        return "WebSocket session id=" + getId();
    }

}