org.springframework.web.socket.sockjs.transport.handler.SockJsWebSocketHandler Maven / Gradle / Ivy
/*
* Copyright 2002-2023 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.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import org.springframework.util.Assert;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.SubProtocolCapable;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;
import org.springframework.web.socket.handler.WebSocketHandlerDecorator;
import org.springframework.web.socket.sockjs.transport.SockJsServiceConfig;
import org.springframework.web.socket.sockjs.transport.session.WebSocketServerSockJsSession;
/**
* An implementation of {@link WebSocketHandler} that adds SockJS messages frames, sends
* SockJS heartbeat messages, and delegates lifecycle events and messages to a target
* {@link WebSocketHandler}.
*
* Methods in this class allow exceptions from the wrapped {@link WebSocketHandler} to
* propagate. However, any exceptions resulting from SockJS message handling (e.g. while
* sending SockJS frames or heartbeat messages) are caught and treated as transport
* errors, i.e. routed to the
* {@link WebSocketHandler#handleTransportError(WebSocketSession, Throwable)
* handleTransportError} method of the wrapped handler and the session closed.
*
* @author Rossen Stoyanchev
* @since 4.0
*/
public class SockJsWebSocketHandler extends TextWebSocketHandler implements SubProtocolCapable {
private final SockJsServiceConfig sockJsServiceConfig;
private final WebSocketServerSockJsSession sockJsSession;
private final List subProtocols;
private final AtomicInteger sessionCount = new AtomicInteger();
public SockJsWebSocketHandler(SockJsServiceConfig serviceConfig, WebSocketHandler webSocketHandler,
WebSocketServerSockJsSession sockJsSession) {
Assert.notNull(serviceConfig, "serviceConfig must not be null");
Assert.notNull(webSocketHandler, "webSocketHandler must not be null");
Assert.notNull(sockJsSession, "session must not be null");
this.sockJsServiceConfig = serviceConfig;
this.sockJsSession = sockJsSession;
webSocketHandler = WebSocketHandlerDecorator.unwrap(webSocketHandler);
this.subProtocols = ((webSocketHandler instanceof SubProtocolCapable subProtocolCapable) ?
new ArrayList<>(subProtocolCapable.getSubProtocols()) : Collections.emptyList());
}
@Override
public List getSubProtocols() {
return this.subProtocols;
}
protected SockJsServiceConfig getSockJsConfig() {
return this.sockJsServiceConfig;
}
@Override
public void afterConnectionEstablished(WebSocketSession wsSession) throws Exception {
Assert.state(this.sessionCount.compareAndSet(0, 1), "Unexpected connection");
this.sockJsSession.initializeDelegateSession(wsSession);
}
@Override
public void handleTextMessage(WebSocketSession wsSession, TextMessage message) throws Exception {
this.sockJsSession.handleMessage(message, wsSession);
}
@Override
public void afterConnectionClosed(WebSocketSession wsSession, CloseStatus status) throws Exception {
this.sockJsSession.delegateConnectionClosed(status);
}
@Override
public void handleTransportError(WebSocketSession webSocketSession, Throwable exception) throws Exception {
this.sockJsSession.delegateError(exception);
}
}