/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 websocket.echo;

import java.nio.ByteBuffer;

import javax.websocket.WebSocketMessage;
import javax.websocket.server.WebSocketEndpoint;

@WebSocketEndpoint("/websocket/echoAnnotation")
public class EchoAnnotation {

    @WebSocketMessage
    public String echoTextMessage(String msg) {
        return msg;
    }

    @WebSocketMessage
    public ByteBuffer echoBinaryMessage(ByteBuffer bb) {
        return bb;
    }
}

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 websocket.echo;

import java.nio.ByteBuffer;

import javax.websocket.PongMessage;
import javax.websocket.WebSocketMessage;
import javax.websocket.server.WebSocketEndpoint;

@WebSocketEndpoint("/websocket/echoAnnotation")
public class EchoAnnotation {

    @WebSocketMessage
    public String echoTextMessage(String msg) {
        return msg;
    }

    @WebSocketMessage
    public ByteBuffer echoBinaryMessage(ByteBuffer bb) {
        return bb;
    }

    /**
     * Process a received pong. This is a NO-OP.
     *
     * @param pm    Ignored.
     */
    @WebSocketMessage
    public void echoPongMessage(PongMessage pm) {
        // NO-OP
    }
}

Add NO-OP for pong messages (to handle unsolicited pongs)