/*
* Copyright 2014-2016 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.integration.websocket.support;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.simp.SimpAttributesContextHolder;
import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
import org.springframework.messaging.simp.SimpMessageType;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.util.Assert;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.messaging.SubProtocolHandler;
/**
* The simple 'pass thru' {@link SubProtocolHandler}, when there is no interests in the
* WebSocket sub-protocols.
* This class just convert {@link Message} to the {@link WebSocketMessage}
* on 'send' part and vise versa - on 'receive' part.
*
* @author Artem Bilan
* @since 4.1
*/
public class PassThruSubProtocolHandler implements SubProtocolHandler {
final List<String> supportedProtocols = new ArrayList<String>();
public void setSupportedProtocols(String... supportedProtocols) {
Assert.noNullElements(supportedProtocols, "'supportedProtocols' must not be empty");
this.supportedProtocols.addAll(Arrays.asList(supportedProtocols));
}
@Override
public List<String> getSupportedProtocols() {
return this.supportedProtocols;
}
@Override
public void handleMessageFromClient(WebSocketSession session, WebSocketMessage<?> webSocketMessage,
MessageChannel outputChannel) throws Exception {
SimpMessageHeaderAccessor headerAccessor = SimpMessageHeaderAccessor.create(SimpMessageType.MESSAGE);
headerAccessor.setSessionId(session.getId());
headerAccessor.setSessionAttributes(session.getAttributes());
headerAccessor.setUser(session.getPrincipal());
headerAccessor.setHeader("content-length", webSocketMessage.getPayloadLength());
headerAccessor.setLeaveMutable(true);
Message<?> message =
MessageBuilder.createMessage(webSocketMessage.getPayload(), headerAccessor.getMessageHeaders());
try {
SimpAttributesContextHolder.setAttributesFromMessage(message);
outputChannel.send(message);
}
finally {
SimpAttributesContextHolder.resetAttributes();
}
}
@Override
public void handleMessageToClient(WebSocketSession session, Message<?> message) throws Exception {
Object payload = message.getPayload();
if (payload instanceof String) {
session.sendMessage(new TextMessage((String) payload));
}
else if (payload instanceof byte[]) {
session.sendMessage(new TextMessage((byte[]) payload));
}
else if (payload instanceof ByteBuffer) {
session.sendMessage(new TextMessage(((ByteBuffer) payload).array()));
}
else {
throw new IllegalArgumentException("Unsupported payload type: " + payload.getClass()
+ ". Can be one of: " + Arrays.<Class<?>>asList(String.class, byte[].class, ByteBuffer.class));
}
}
@Override
public String resolveSessionId(Message<?> message) {
return SimpMessageHeaderAccessor.getSessionId(message.getHeaders());
}
@Override
public void afterSessionStarted(WebSocketSession session, MessageChannel outputChannel) throws Exception {
// Subclasses might implement this method
}
@Override
public void afterSessionEnded(WebSocketSession session, CloseStatus closeStatus, MessageChannel outputChannel)
throws Exception {
// Subclasses might implement this method
}
}