java使用websocket搭建客户端和服务端

maven

<dependency>
    <groupId>org.java-websocketgroupId>
    <artifactId>Java-WebSocketartifactId>
    <version>1.5.4version>
dependency>

客户端

package demo.wsdemo;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Map;
import java.util.Scanner;

import org.java_websocket.client.WebSocketClient;
import org.java_websocket.drafts.Draft;
import org.java_websocket.handshake.ServerHandshake;

public class WsClient extends WebSocketClient {
    public WsClient(URI serverUri, Draft draft) {
        super(serverUri, draft);
    }

    public WsClient(URI serverURI) {
        super(serverURI);
    }

    public WsClient(URI serverUri, Map<String, String> httpHeaders) {
        super(serverUri, httpHeaders);
    }

    @Override
    public void onOpen(ServerHandshake handshakedata) {
        send("Hello, it is me. Mario :)");
        System.out.println("opened connection");
        // if you plan to refuse connection based on ip or httpfields overload: onWebsocketHandshakeReceivedAsClient
    }

    @Override
    public void onMessage(String message) {
        System.out.println("received: " + message);
    }

    @Override
    public void onClose(int code, String reason, boolean remote) {
        // The close codes are documented in class org.java_websocket.framing.CloseFrame
        System.out.println(
                "Connection closed by " + (remote ? "remote peer" : "us") + " Code: " + code + " Reason: "
                        + reason);
    }

    @Override
    public void onError(Exception ex) {
        ex.printStackTrace();
        // if the error is fatal then onClose will be called additionally
    }

    public static void main(String[] args) throws URISyntaxException {

        WsClient c = new WsClient(new URI(
                "ws://localhost:8887"));
        Scanner scanner = new Scanner(System.in);
        new Thread(c::connect).start();
        while (true){
            String input = scanner.nextLine();
            c.send(input);
        }
    }

}

服务端

package demo.wsdemo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.util.Collections;
import org.java_websocket.WebSocket;
import org.java_websocket.drafts.Draft;
import org.java_websocket.drafts.Draft_6455;
import org.java_websocket.handshake.ClientHandshake;
import org.java_websocket.server.WebSocketServer;
public class WsServer extends WebSocketServer{
    public WsServer(int port)  {
        super(new InetSocketAddress(port));
    }

    public WsServer(InetSocketAddress address) {
        super(address);
    }

    public WsServer(int port, Draft_6455 draft) {
        super(new InetSocketAddress(port), Collections.<Draft>singletonList(draft));
    }

    @Override
    public void onOpen(WebSocket conn, ClientHandshake handshake) {
        conn.send("Welcome to the server!"); //This method sends a message to the new client
        broadcast("new connection: " + handshake
                .getResourceDescriptor()); //This method sends a message to all clients connected
        System.out.println(
                conn.getRemoteSocketAddress().getAddress().getHostAddress() + " entered the room!");
    }

    @Override
    public void onClose(WebSocket conn, int code, String reason, boolean remote) {
        broadcast(conn + " has left the room!");
        System.out.println(conn + " has left the room!");
    }

    @Override
    public void onMessage(WebSocket conn, String message) {
        broadcast(message);
        System.out.println(conn + ": " + message);
    }

    @Override
    public void onMessage(WebSocket conn, ByteBuffer message) {
        broadcast(message.array());
        System.out.println(conn + ": " + message);
    }


    public static void main(String[] args) throws InterruptedException, IOException {
        int port = 8887; // 843 flash policy port
        try {
            port = Integer.parseInt(args[0]);
        } catch (Exception ex) {
        }
        WsServer s = new WsServer(port);
        s.start();
        System.out.println("ChatServer started on port: " + s.getPort());

        BufferedReader sysin = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String in = sysin.readLine();
            s.broadcast(in);
            if (in.equals("exit")) {
                s.stop(1000);
                break;
            }
        }
    }

    @Override
    public void onError(WebSocket conn, Exception ex) {
        ex.printStackTrace();
        if (conn != null) {
            // some errors like port binding failed may not be assignable to a specific websocket
        }
    }

    @Override
    public void onStart() {
        System.out.println("Server started!");
        setConnectionLostTimeout(0);
        setConnectionLostTimeout(100);
    }
}