org.springframework.web.socket.sockjs.transport.handler.XhrStreamingTransportHandler Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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
*
* https://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.handler;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Map;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.sockjs.frame.DefaultSockJsFrameFormat;
import org.springframework.web.socket.sockjs.frame.SockJsFrameFormat;
import org.springframework.web.socket.sockjs.transport.SockJsServiceConfig;
import org.springframework.web.socket.sockjs.transport.SockJsSession;
import org.springframework.web.socket.sockjs.transport.TransportHandler;
import org.springframework.web.socket.sockjs.transport.TransportType;
import org.springframework.web.socket.sockjs.transport.session.StreamingSockJsSession;
/**
* A {@link TransportHandler} that sends messages over an HTTP streaming request.
*
* @author Rossen Stoyanchev
* @since 4.0
*/
public class XhrStreamingTransportHandler extends AbstractHttpSendingTransportHandler {
private static final byte[] PRELUDE = new byte[2049];
static {
Arrays.fill(PRELUDE, (byte) 'h');
PRELUDE[2048] = '\n';
}
@Override
public TransportType getTransportType() {
return TransportType.XHR_STREAMING;
}
@Override
protected MediaType getContentType() {
return new MediaType("application", "javascript", StandardCharsets.UTF_8);
}
@Override
public boolean checkSessionType(SockJsSession session) {
return (session instanceof XhrStreamingSockJsSession);
}
@Override
public StreamingSockJsSession createSession(
String sessionId, WebSocketHandler handler, Map attributes) {
return new XhrStreamingSockJsSession(sessionId, getServiceConfig(), handler, attributes);
}
@Override
protected SockJsFrameFormat getFrameFormat(ServerHttpRequest request) {
return new DefaultSockJsFrameFormat("%s\n");
}
private static class XhrStreamingSockJsSession extends StreamingSockJsSession {
public XhrStreamingSockJsSession(String sessionId, SockJsServiceConfig config,
WebSocketHandler wsHandler, Map attributes) {
super(sessionId, config, wsHandler, attributes);
}
@Override
protected byte[] getPrelude(ServerHttpRequest request) {
return PRELUDE;
}
}
}