org.springframework.web.socket.sockjs.transport.AbstractHttpSendingTransportHandler.java Source code

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Here is the source code for org.springframework.web.socket.sockjs.transport.AbstractHttpSendingTransportHandler.java

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/*
 * Copyright 2002-2013 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.sockjs.transport;

import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.sockjs.AbstractSockJsSession;
import org.springframework.web.socket.sockjs.ConfigurableTransportHandler;
import org.springframework.web.socket.sockjs.SockJsConfiguration;
import org.springframework.web.socket.sockjs.SockJsFrame;
import org.springframework.web.socket.sockjs.SockJsFrame.FrameFormat;
import org.springframework.web.socket.sockjs.SockJsSessionFactory;
import org.springframework.web.socket.sockjs.TransportErrorException;

/**
 * Base class for HTTP-based transports that send messages over HTTP.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public abstract class AbstractHttpSendingTransportHandler
        implements ConfigurableTransportHandler, SockJsSessionFactory {

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

    private SockJsConfiguration sockJsConfig;

    @Override
    public void setSockJsConfiguration(SockJsConfiguration sockJsConfig) {
        this.sockJsConfig = sockJsConfig;
    }

    public SockJsConfiguration getSockJsConfig() {
        return this.sockJsConfig;
    }

    @Override
    public final void handleRequest(ServerHttpRequest request, ServerHttpResponse response,
            WebSocketHandler webSocketHandler, AbstractSockJsSession session) throws TransportErrorException {

        // Set content type before writing
        response.getHeaders().setContentType(getContentType());

        AbstractHttpSockJsSession httpServerSession = (AbstractHttpSockJsSession) session;
        handleRequestInternal(request, response, httpServerSession);
    }

    protected void handleRequestInternal(ServerHttpRequest request, ServerHttpResponse response,
            AbstractHttpSockJsSession httpServerSession) throws TransportErrorException {

        if (httpServerSession.isNew()) {
            logger.debug("Opening " + getTransportType() + " connection");
            httpServerSession.setInitialRequest(request, response, getFrameFormat(request));
        } else if (!httpServerSession.isActive()) {
            logger.debug("starting " + getTransportType() + " async request");
            httpServerSession.setLongPollingRequest(request, response, getFrameFormat(request));
        } else {
            try {
                logger.debug("another " + getTransportType() + " connection still open: " + httpServerSession);
                SockJsFrame closeFrame = SockJsFrame.closeFrameAnotherConnectionOpen();
                response.getBody().write(getFrameFormat(request).format(closeFrame).getContentBytes());
            } catch (IOException e) {
                throw new TransportErrorException("Failed to send SockJS close frame", e,
                        httpServerSession.getId());
            }
        }
    }

    protected abstract MediaType getContentType();

    protected abstract FrameFormat getFrameFormat(ServerHttpRequest request);

}