Establishing a WebSocket client connection in Jetty?

Question

I'm following this tutorial to establish a WebSocket connection to a server: http://www.eclipse.org/jetty/documentation/current/jetty-websocket-client-api.html

The code (same as the tutorial):

import java.net.URI;
import org.eclipse.jetty.websocket.client.ClientUpgradeRequest;
import org.eclipse.jetty.websocket.client.WebSocketClient;

/**
 * Example of a simple Echo Client.
 */
public class SimpleEchoClient {

    public static void main(String[] args) {
        String destUri = "ws://echo.websocket.org";
        if (args.length > 0) {
            destUri = args[0];
        }
        WebSocketClient client = new WebSocketClient();
        SimpleEchoClient socket = new SimpleEchoClient();

        try {
            client.start();
            URI echoUri = new URI(destUri);
            ClientUpgradeRequest request = new ClientUpgradeRequest();
            client.connect(socket, echoUri, request);
            System.out.printf("Connecting to : %s%n", echoUri);
           // socket.awaitClose(5, TimeUnit.SECONDS);
        } catch (Throwable t) {
            t.printStackTrace();
        } finally {
            try {
                client.stop();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

Errors:

2014-08-07 21:49:00.346:INFO::main: Logging initialized @86ms
org.eclipse.jetty.websocket.api.InvalidWebSocketException:
SimpleEchoClient is not a valid WebSocket object.  
Object must obey one of the following rules:  
(1) class implements org.eclipse.jetty.websocket.api.WebSocketListener or  
(2) class is annotated with @org.eclipse.jetty.websocket.api.annotations.WebSocket

at org.eclipse.jetty.websocket.common.events.EventDriverFactory.wrap(EventDriverFactory.java:145)
at org.eclipse.jetty.websocket.client.WebSocketClient.connect(WebSocketClient.java:200)
at org.eclipse.jetty.websocket.client.WebSocketClient.connect(WebSocketClient.java:144)
at SimpleEchoClient.main(SimpleEchoClient.java:31)

I'm not too sure what is wrong with my imported jar file. Maybe it is the wrong one? I'm using this: http://mvnrepository.com/artifact/org.eclipse.jetty.websocket/websocket-client/9.2.2.v20140723

Surely there must be an easier way to establish a connection via Jetty Websocket and start receiving data?

Answer 1

It looks like the documentation is out-of-date with the current version you are using. Try rolling back to a more stable version of 9.2.x like:

<dependency>
    <groupId>org.eclipse.jetty.websocket</groupId>
    <artifactId>websocket-client</artifactId>
    <version>9.2.0.RC0</version>
</dependency>

Answer 2

正如Kayman在评论中所解释的那样，您对套接字处理程序实现的问题，请使用此处介绍的最新版本以及一个示例（您使用过但正确）进行了解释。http://www.eclipse.org/jetty/documentation/current/jetty-websocket -client-api.html