Sending BinaryMessage from java WebSocketStompClient
According to ( Is it possible to send binary data with STOMP over WebSockets using Spring-WebSockets? ) It is possible that it is possible to send binary messages with STOMP over websites.
I configured the WebSocketStompClient like this:
List<Transport> transports = new ArrayList<>(1);
transports.add(new WebSocketTransport( new StandardWebSocketClient()) );
WebSocketClient transport = new SockJsClient(transports);
WebSocketStompClient stompClient = new WebSocketStompClient(transport);
// using a custom converter to serialize java object to byte[]
stompClient.setMessageConverter( new SerializedJavaObjectMessageConverter() );
I use the following to send a message:
StompHeaders stompHeaders = new StompHeaders();
stompHeaders.setDestination( "/app/greetings");
stompHeaders.setContentType( MimeTypeUtils.APPLICATION_OCTET_STREAM );
session.send(stompHeaders, new Greeting( message ));
I get an exception from the following statement:
Assert.isInstanceOf(TextMessage.class, message, this + " supports text messages only.");
found in org.springframework.web.socket.sockjs.client.AbstractClientSockJs (below) which appears to support TextMessage:
@Override
public final void sendMessage(WebSocketMessage<?> message) throws IOException {
Assert.state(State.OPEN.equals(this.state), this + " is not open, current state=" + this.state);
Assert.isInstanceOf(TextMessage.class, message, this + " supports text messages only.");
String payload = ((TextMessage) message).getPayload();
payload = getMessageCodec().encode(new String[] { payload });
payload = payload.substring(1); // the client-side doesn't need message framing (letter "a")
message = new TextMessage(payload);
if (logger.isTraceEnabled()) {
logger.trace("Sending message " + message + " in " + this);
}
sendInternal((TextMessage) message);
}
Does the new java client WebSocketStompClient (4.2-SNAPSHOT) as above (i.e. using SockJS for backup) support sending binary messages?
UPDATE:
The following client configuration works:
WebSocketClient transport = new StandardWebSocketClient();
WebSocketStompClient stompClient = new WebSocketStompClient(transport)
source to share
I managed to get this to work by sending a TextMessage instead. I created another custom MessageConverter that Base64 encodes / decodes a serialized object:
public class Base64JavaObjectMessageConverter extends AbstractMessageConverter {
public Base64JavaObjectMessageConverter() {
super(MimeTypeUtils.TEXT_PLAIN);
}
@Override
protected boolean supports(Class<?> clazz) {
return true;
}
@Override
public Object convertFromInternal(Message<?> message, Class<?> targetClass) {
byte[] messageBytes = Base64.getDecoder().decode( (byte[])message.getPayload() );
return SerializationUtils.deserialize( messageBytes );
}
@Override
public Object convertToInternal(Object payload, MessageHeaders headers) {
byte[] messageBytes = SerializationUtils.serialize( payload );
return Base64.getEncoder().encode( messageBytes);
}
}
source to share