如何从Android应用程序连接到Web套接字服务器

Question

我在java中做过一个聊天web-socket应用程序服务器，我也创建了一个小型的android聊天应用程序。

import android.util.Log;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.drafts.Draft_17;
import org.java_websocket.handshake.ServerHandshake;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.Map;

public class MyWebSocketClient {
    private WebSocketClient mWebSocketClient;

    public void connect_to_server() {
        URI uri;
        try {
            uri = new URI("ws://172.16.0.146:8082/PChat/chat");
        } catch (URISyntaxException e) {
            e.printStackTrace();
            return;
        }

        Map<String, String> headers = new HashMap<>();

        mWebSocketClient = new WebSocketClient(uri, new Draft_17(), headers, 0) {
            @Override
            public void onOpen(ServerHandshake serverHandshake) {
                Log.i("Websocket", "Opened");
              //  mWebSocketClient.send("Hello from websocket client");
            }

            @Override
            public void onMessage(String s) {
                Log.i("Websocket", "onMessage"+s);
            }

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

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

    public void sendMessage(String message) {

        mWebSocketClient.send(message);
    }

}

这是用于连接到web-socket的代码。连接正在发生，但在第二个连接中正在下垂。

01-08 10:53:10.900 1843-1843/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.pchat.nanobi.pchat, PID: 1843
org.java_websocket.exceptions.WebsocketNotConnectedException
    at org.java_websocket.WebSocketImpl.send(WebSocketImpl.java:566)
    at org.java_websocket.WebSocketImpl.send(WebSocketImpl.java:543)
    at org.java_websocket.client.WebSocketClient.send(WebSocketClient.java:171)
    at com.pchat.nanobi.pchat.MainActivity.sendMessage(MainActivity.java:109)
    at com.pchat.nanobi.pchat.MainActivity$2.onClick(MainActivity.java:58)
    at android.view.View.performClick(View.java:4785)
    at android.view.View$PerformClick.run(View.java:19884)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5343)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)

如何从android连接到web-socket服务器？

Answer 1

使用依赖：Java-WebSocket-1.3.0.jar

import org.java_websocket.client.WebSocketClient;
import org.java_websocket.drafts.Draft_17;
import org.java_websocket.handshake.ServerHandshake;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.Map;

public class WebsocketClientExample  {

    private WebSocketClient mWebSocketClient;

    public void connect_to_server() {
        URI uri;
        try {
            uri = new URI("ws://path/to/your/websocket/endpoint");
        } catch (URISyntaxException e) {
            e.printStackTrace();
            return;
        }

        Map<String, String> headers = new HashMap<>();

        mWebSocketClient = new WebSocketClient(uri, new Draft_17(), headers, 0) {
            @Override
            public void onOpen(ServerHandshake serverHandshake) {
                Log.i("Websocket", "Opened");
                mWebSocketClient.send("Hello from websocket client");
            }

            @Override
            public void onMessage(String s) {
                Log.i("Websocket", "onMessage"+s);
            }

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

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