WebSocket: Validate for parameters onMessage message handler

[dalidia]

Description:

Currently, if a user adds a non-valid parameter to methods annotated with @onMessage to classes annotated with @ServerEndpoint or @ClientEndpoint, it will create a server error, leaving the server unresponsive. However, the user is not notified of this in the IDE. Only a small error shows up in the terminal.

For this reason, we need to apply a validation of parameters for the onMessage lifecycle method.

Specification:

Each OnMessage method handles: text, binary and pong, per JakartaEE specs found here

Acceptable

@OnMessage
public void validMessage(String message, Session session) {
    System.out.println("Program requested " + message + " using " + session.getId());
    session.getAsyncRemote().sendText("Lucky says hi");
}

Error

@OnMessage
public void notValidMessage(Object invalidMessage, Session session) {
   System.out.println("Method has invalid parameter java.lang.Class. " + invalidParameter + " using " + session.getId());
   session.getAsyncRemote().sendText("I am pong");
}

Type of language feature proposed:

Select all that apply

• [x] diagnostic
• [ ] quick-fix
• [ ] snippet
• [ ] other, please specify: