# The Java EE 7 Tutorial

# 18.9 Handling Errors

To designate a method that handles errors in an annotated WebSocket endpoint, decorate it with `@OnError`:

    @ServerEndpoint("/testendpoint")
    public class TestEndpoint {
       ...
       @OnError
       public void error(Session session, Throwable t) {
          t.printStackTrace();
          ...
       }
    }

This method is invoked when there are connection problems, runtime errors from message handlers, or conversion errors when decoding messages.