/*
* 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.reactive.socket.adapter;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.function.Function;
import javax.websocket.CloseReason;
import javax.websocket.Endpoint;
import javax.websocket.EndpointConfig;
import javax.websocket.PongMessage;
import javax.websocket.Session;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.util.Assert;
import org.springframework.web.reactive.socket.CloseStatus;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.WebSocketMessage;
import org.springframework.web.reactive.socket.WebSocketMessage.Type;
import org.springframework.web.reactive.socket.WebSocketSession;
/**
* Adapter for Java WebSocket API (JSR-356) that delegates events to a reactive
* {@link WebSocketHandler} and its session.
*
* @author Violeta Georgieva
* @author Rossen Stoyanchev
* @since 5.0
*/
public class StandardWebSocketHandlerAdapter extends Endpoint {
private final WebSocketHandler delegateHandler;
private Function<Session, StandardWebSocketSession> sessionFactory;
private StandardWebSocketSession delegateSession;
public StandardWebSocketHandlerAdapter(WebSocketHandler handler,
Function<Session, StandardWebSocketSession> sessionFactory) {
Assert.notNull(handler, "WebSocketHandler is required");
Assert.notNull(sessionFactory, "'sessionFactory' is required");
this.delegateHandler = handler;
this.sessionFactory = sessionFactory;
}
@Override
public void onOpen(Session session, EndpointConfig config) {
this.delegateSession = this.sessionFactory.apply(session);
session.addMessageHandler(String.class, message -> {
WebSocketMessage webSocketMessage = toMessage(message);
this.delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
});
session.addMessageHandler(ByteBuffer.class, message -> {
WebSocketMessage webSocketMessage = toMessage(message);
this.delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
});
session.addMessageHandler(PongMessage.class, message -> {
WebSocketMessage webSocketMessage = toMessage(message);
this.delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
});
this.delegateHandler.handle(this.delegateSession).subscribe(this.delegateSession);
}
private <T> WebSocketMessage toMessage(T message) {
WebSocketSession session = this.delegateSession;
Assert.state(session != null, "Cannot create message without a session");
if (message instanceof String) {
byte[] bytes = ((String) message).getBytes(StandardCharsets.UTF_8);
return new WebSocketMessage(Type.TEXT, session.bufferFactory().wrap(bytes));
}
else if (message instanceof ByteBuffer) {
DataBuffer buffer = session.bufferFactory().wrap((ByteBuffer) message);
return new WebSocketMessage(Type.BINARY, buffer);
}
else if (message instanceof PongMessage) {
DataBuffer buffer = session.bufferFactory().wrap(((PongMessage) message).getApplicationData());
return new WebSocketMessage(Type.PONG, buffer);
}
else {
throw new IllegalArgumentException("Unexpected message type: " + message);
}
}
@Override
public void onClose(Session session, CloseReason reason) {
if (this.delegateSession != null) {
int code = reason.getCloseCode().getCode();
this.delegateSession.handleClose(new CloseStatus(code, reason.getReasonPhrase()));
}
}
@Override
public void onError(Session session, Throwable exception) {
if (this.delegateSession != null) {
this.delegateSession.handleError(exception);
}
}
}