javax.websocket 客户端简单例子

javax.websocket client simple example

提问by Martin

Can someone please provide me very simple example of websocket client using javax.websocket?

有人可以给我提供一个非常简单的 websocket 客户端使用示例javax.websocket吗？

I want to connect to websocket (ws://socket.example.com:1234), send message (add channel) and listen to messages. All messages (sent & listened) are in JSON format.

我想连接到 websocket (ws://socket.example.com:1234)，发送消息（添加通道）并收听消息。所有消息（发送和收听）都是 JSON 格式。

And btw is this library the best for simple websocket communication?

顺便说一句，这个库是最适合简单 websocket 通信的库吗？

采纳答案by Martin

I've found a great example using javax.websockethere:

我在javax.websocket这里找到了一个很好的例子：

http://www.programmingforliving.com/2013/08/jsr-356-java-api-for-websocket-client-api.html

http://www.programmingforliving.com/2013/08/jsr-356-java-api-for-websocket-client-api.html

Here the code based on the example linked above:

这里的代码基于上面链接的示例：

TestApp.java:

TestApp.java：

package testapp;

import java.net.URI;
import java.net.URISyntaxException;

public class TestApp {

    public static void main(String[] args) {
        try {
            // open websocket
            final WebsocketClientEndpoint clientEndPoint = new WebsocketClientEndpoint(new URI("wss://real.okcoin.cn:10440/websocket/okcoinapi"));

            // add listener
            clientEndPoint.addMessageHandler(new WebsocketClientEndpoint.MessageHandler() {
                public void handleMessage(String message) {
                    System.out.println(message);
                }
            });

            // send message to websocket
            clientEndPoint.sendMessage("{'event':'addChannel','channel':'ok_btccny_ticker'}");

            // wait 5 seconds for messages from websocket
            Thread.sleep(5000);

        } catch (InterruptedException ex) {
            System.err.println("InterruptedException exception: " + ex.getMessage());
        } catch (URISyntaxException ex) {
            System.err.println("URISyntaxException exception: " + ex.getMessage());
        }
    }
}

WebsocketClientEndpoint.java:

WebsocketClientEndpoint.java：

package testapp;

import java.net.URI;
import javax.websocket.ClientEndpoint;
import javax.websocket.CloseReason;
import javax.websocket.ContainerProvider;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.WebSocketContainer;

/**
 * ChatServer Client
 *
 * @author Jiji_Sasidharan
 */
@ClientEndpoint
public class WebsocketClientEndpoint {

    Session userSession = null;
    private MessageHandler messageHandler;

    public WebsocketClientEndpoint(URI endpointURI) {
        try {
            WebSocketContainer container = ContainerProvider.getWebSocketContainer();
            container.connectToServer(this, endpointURI);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Callback hook for Connection open events.
     *
     * @param userSession the userSession which is opened.
     */
    @OnOpen
    public void onOpen(Session userSession) {
        System.out.println("opening websocket");
        this.userSession = userSession;
    }

    /**
     * Callback hook for Connection close events.
     *
     * @param userSession the userSession which is getting closed.
     * @param reason the reason for connection close
     */
    @OnClose
    public void onClose(Session userSession, CloseReason reason) {
        System.out.println("closing websocket");
        this.userSession = null;
    }

    /**
     * Callback hook for Message Events. This method will be invoked when a client send a message.
     *
     * @param message The text message
     */
    @OnMessage
    public void onMessage(String message) {
        if (this.messageHandler != null) {
            this.messageHandler.handleMessage(message);
        }
    }

    /**
     * register message handler
     *
     * @param msgHandler
     */
    public void addMessageHandler(MessageHandler msgHandler) {
        this.messageHandler = msgHandler;
    }

    /**
     * Send a message.
     *
     * @param message
     */
    public void sendMessage(String message) {
        this.userSession.getAsyncRemote().sendText(message);
    }

    /**
     * Message handler.
     *
     * @author Jiji_Sasidharan
     */
    public static interface MessageHandler {

        public void handleMessage(String message);
    }
}

回答by TCassells

TooTallNate has a simple client side https://github.com/TooTallNate/Java-WebSocket

TooTallNate 有一个简单的客户端https://github.com/TooTallNate/Java-WebSocket

Just add the java_websocket.jar in the dist folder into your project.

只需将 dist 文件夹中的 java_websocket.jar 添加到您的项目中。

 import org.java_websocket.client.WebSocketClient;
 import org.java_websocket.drafts.Draft_10;
 import org.java_websocket.handshake.ServerHandshake;
 import org.json.JSONException;
 import org.json.JSONObject;

  WebSocketClient mWs = new WebSocketClient( new URI( "ws://socket.example.com:1234" ), new Draft_10() )
{
                    @Override
                    public void onMessage( String message ) {
                     JSONObject obj = new JSONObject(message);
                     String channel = obj.getString("channel");
                    }

                    @Override
                    public void onOpen( ServerHandshake handshake ) {
                        System.out.println( "opened connection" );
                    }

                    @Override
                    public void onClose( int code, String reason, boolean remote ) {
                        System.out.println( "closed connection" );
                    }

                    @Override
                    public void onError( Exception ex ) {
                        ex.printStackTrace();
                    }

                };
 //open websocket
 mWs.connect();
 JSONObject obj = new JSONObject();
 obj.put("event", "addChannel");
 obj.put("channel", "ok_btccny_ticker");
 String message = obj.toString();
 //send message
 mWs.send(message);

// and to close websocket

// 并关闭 websocket

 mWs.close();

回答by vinu

Here is one simple example.. you can download and test it http://www.pretechsol.com/2014/12/java-ee-websocket-simple-example.html

这是一个简单的例子..你可以下载并测试它 http://www.pretechsol.com/2014/12/java-ee-websocket-simple-example.html

回答by Koekiebox

Have a look at this Java EE 7 examples from Arun Gupta.

看看这个来自 Arun Gupta 的 Java EE 7 示例。

I forked it on github.

我在 github 上分叉了它。

Main

主要的

/**
 * @author Arun Gupta
 */
public class Client {

    final static CountDownLatch messageLatch = new CountDownLatch(1);

    public static void main(String[] args) {
        try {
            WebSocketContainer container = ContainerProvider.getWebSocketContainer();
            String uri = "ws://echo.websocket.org:80/";
            System.out.println("Connecting to " + uri);
            container.connectToServer(MyClientEndpoint.class, URI.create(uri));
            messageLatch.await(100, TimeUnit.SECONDS);
        } catch (DeploymentException | InterruptedException | IOException ex) {
            Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

ClientEndpoint

客户端端点

/**
 * @author Arun Gupta
 */
@ClientEndpoint
public class MyClientEndpoint {
    @OnOpen
    public void onOpen(Session session) {
        System.out.println("Connected to endpoint: " + session.getBasicRemote());
        try {
            String name = "Duke";
            System.out.println("Sending message to endpoint: " + name);
            session.getBasicRemote().sendText(name);
        } catch (IOException ex) {
            Logger.getLogger(MyClientEndpoint.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    @OnMessage
    public void processMessage(String message) {
        System.out.println("Received message in client: " + message);
        Client.messageLatch.countDown();
    }

    @OnError
    public void processError(Throwable t) {
        t.printStackTrace();
    }
}

回答by Muhammed Fasil

Use this library org.java_websocket

使用这个库 org.java_websocket

First thing you should import that library in build.gradle

首先应该在 build.gradle 中导入该库

repositories {
 mavenCentral()
 }

then add the implementation in dependency{}

然后在依赖项中添加实现{}

implementation "org.java-websocket:Java-WebSocket:1.3.0"

Then you can use this code

然后你可以使用这个代码

In your activity declare object for Websocketclient like

在您的活动中为 Websocketclient 声明对象，例如

private WebSocketClient mWebSocketClient;

then add this method for callback

然后添加此方法用于回调

 private void ConnectToWebSocket() {
URI uri;
try {
    uri = new URI("ws://your web socket url");
} catch (URISyntaxException e) {
    e.printStackTrace();
    return;
}

mWebSocketClient = new WebSocketClient(uri) {
    @Override
    public void onOpen(ServerHandshake serverHandshake) {
        Log.i("Websocket", "Opened");
        mWebSocketClient.send("Hello from " + Build.MANUFACTURER + " " + Build.MODEL);
    }

    @Override
    public void onMessage(String s) {
        final String message = s;
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                TextView textView = (TextView)findViewById(R.id.edittext_chatbox);
                textView.setText(textView.getText() + "\n" + message);
            }
        });
    }

    @Override
    public void onClose(int i, String s, boolean b) {
        Log.i("Websocket", "Closed " + s);
    }

    @Override
    public void onError(Exception e) {
        Log.i("Websocket", "Error " + e.getMessage());
    }
};
mWebSocketClient.connect();

}

}

回答by veritas

I have Spring 4.2 in my project and many SockJS Stomp implementations usually work well with Spring Boot implementations. This implementation from Baeldungworked(for me without changing from Spring 4.2 to 5). After Using the dependencies mentioned in his blog, it still gave me ClassNotFoundError. I added the below dependency to fix it.

我的项目中有 Spring 4.2，许多 SockJS Stomp 实现通常与 Spring Boot 实现配合良好。Baeldung 的这个实现有效（对我来说没有从 Spring 4.2 更改为 5）。使用了他博客中提到的依赖后，还是给了我ClassNotFoundError。我添加了以下依赖项来修复它。

<dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>4.2.3.RELEASE</version>
    </dependency>