android接入websocket步驟,建立一個長連接（帶心跳檢測）從服務器端接收訊息

1.首先需要在AndroidManifest.xml中開啟一個服務：

<!-- 后臺服務-長連接 -->
<service android:name=".service.BackService" />

2.添加參考

implementation 'com.squareup.okhttp3:okhttp:3.12.1'

3.寫一個類BackService繼承Service：

public class BackService extends Service{
    @Override
    public void onCreate() {
        super.onCreate();
    }
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

4.在BackService的onCreate()方法中開啟一個執行緒：

@Override
    public void onCreate() {
        super.onCreate();
        new InitSocketThread().start();
    }

class InitSocketThread extends Thread {
        @Override
        public void run() {
            super.run();
            try {
                initSocket();
            } catch (UnknownHostException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

 

    /**
     * 心跳檢測時間
     */
    private static final long HEART_BEAT_RATE = 15 * 1000;//每隔15秒進行一次對長連接的心跳檢測
    private static final String WEBSOCKET_HOST_AND_PORT = "ws://xxx:9501";//可替換為自己的主機名和埠號
    private WebSocket mWebSocket;
    // 初始化socket
    private void initSocket() throws UnknownHostException, IOException {
        OkHttpClient client = new OkHttpClient.Builder().readTimeout(0, TimeUnit.MILLISECONDS).build();
        Request request = new Request.Builder().url(WEBSOCKET_HOST_AND_PORT).build();
        client.newWebSocket(request, new WebSocketListener() {
            @Override
            public void onOpen(WebSocket webSocket, Response response) {//開啟長連接成功的回呼
                super.onOpen(webSocket, response);
                mWebSocket = webSocket;
            }
 
            @Override
            public void onMessage(WebSocket webSocket, String text) {//接收訊息的回呼
                super.onMessage(webSocket, text);
                //收到服務器端傳過來的訊息text
            }
 
            @Override
            public void onMessage(WebSocket webSocket, ByteString bytes) {
                super.onMessage(webSocket, bytes);
            }
 
            @Override
            public void onClosing(WebSocket webSocket, int code, String reason) {
                super.onClosing(webSocket, code, reason);
            }
 
            @Override
            public void onClosed(WebSocket webSocket, int code, String reason) {
                super.onClosed(webSocket, code, reason);
            }
 
            @Override
            public void onFailure(WebSocket webSocket, Throwable t, @Nullable Response response) {//長連接連接失敗的回呼
                super.onFailure(webSocket, t, response);
            }
        });
        client.dispatcher().executorService().shutdown();
        mHandler.postDelayed(heartBeatRunnable, HEART_BEAT_RATE);//開啟心跳檢測
    }

5.開啟心跳檢測：

private long sendTime = 0L;
// 發送心跳包
    private Handler mHandler = new Handler();
    private Runnable heartBeatRunnable = new Runnable() {
        @Override
        public void run() {
            if (System.currentTimeMillis() - sendTime >= HEART_BEAT_RATE) {
                boolean isSuccess = mWebSocket.send("");//發送一個空訊息給服務器，通過發送訊息的成功失敗來判斷長連接的連接狀態
                if (!isSuccess) {//長連接已斷開
                    mHandler.removeCallbacks(heartBeatRunnable);
                    mWebSocket.cancel();//取消掉以前的長連接
                    new InitSocketThread().start();//創建一個新的連接
                } else {//長連接處于連接狀態
                    
                }
 
                sendTime = System.currentTimeMillis();
            }
            mHandler.postDelayed(this, HEART_BEAT_RATE);//每隔一定的時間，對長連接進行一次心跳檢測
        }
    };

6.當BackService關閉時，關閉掉長連接：

@Override
    public void onDestroy() {
        super.onDestroy();
        if (mWebSocket != null) {
            mWebSocket.close(1000, null);
        }
    }

7.BackService類完整代碼

import android.app.Application;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.util.Log;

import androidx.annotation.Nullable;

import com.example.mytest.application.BaseApplication;

import java.io.IOException;
import java.net.UnknownHostException;
import java.util.concurrent.TimeUnit;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.WebSocket;
import okhttp3.WebSocketListener;
import okio.ByteString;

public class BackService extends Service {

    public Application application;

    public Context context;

    /**
     * 心跳檢測時間
     */
    private static final long HEART_BEAT_RATE = 15 * 1000;//每隔15秒進行一次對長連接的心跳檢測
    private static final String WEBSOCKET_HOST_AND_PORT = "ws://172.20.13.91:8004/websocket/";//可替換為自己的主機名和埠號
    private WebSocket mWebSocket;

    @Override
    public void onCreate() {
        super.onCreate();

        if (mWebSocket != null) {
            mWebSocket.close(1000, null);
        }
        new InitSocketThread().start();
        //application= BaseApplication.getApplication();//這個是application，需要在功能清單里面的--android:name=".main.app.TzApplication"
        //context=BaseApplication.getApplication();
        Log.e("TAG","onCreate------------*************-------------");
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mWebSocket != null){
            mWebSocket.close(1000,null);
        }
    }




    public class InitSocketThread extends Thread {
        @Override
        public void run() {
            super.run();
            try {
                initSocket();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }

        // 初始化socket
        private void initSocket() throws UnknownHostException, IOException {
            OkHttpClient client = new OkHttpClient.Builder().readTimeout(0, TimeUnit.MILLISECONDS).build();
            Request request = new Request.Builder().url(WEBSOCKET_HOST_AND_PORT).build();
            client.newWebSocket(request, new WebSocketListener() {
                @Override
                public void onOpen(WebSocket webSocket, Response response) {//開啟長連接成功的回呼
                    super.onOpen(webSocket, response);
                    mWebSocket = webSocket;
                }

                @Override
                public void onMessage(WebSocket webSocket, String text) {//接收訊息的回呼
                    super.onMessage(webSocket, text);
                    //收到服務器端傳過來的訊息text
                    Log.e("TAG", "收到來自后臺的資訊-------------" + text);
                }

                @Override
                public void onMessage(WebSocket webSocket, ByteString bytes) {
                    super.onMessage(webSocket, bytes);
                }

                @Override
                public void onClosing(WebSocket webSocket, int code, String reason) {
                    super.onClosing(webSocket, code, reason);
                }

                @Override
                public void onClosed(WebSocket webSocket, int code, String reason) {
                    super.onClosed(webSocket, code, reason);
                }

                @Override
                public void onFailure(WebSocket webSocket, Throwable t, @Nullable Response response) {//長連接連接失敗的回呼
                    super.onFailure(webSocket, t, response);
                }
            });
            client.dispatcher().executorService().shutdown();
            mHandler.postDelayed(heartBeatRunnable, HEART_BEAT_RATE);//開啟心跳檢測
        }

        private long sendTime = 0L;
        // 發送心跳包
        private Handler mHandler = new Handler();
        private Runnable heartBeatRunnable = new Runnable() {
            @Override
            public void run() {
                if (System.currentTimeMillis() - sendTime >= HEART_BEAT_RATE) {
                    boolean isSuccess = mWebSocket.send("");//發送一個空訊息給服務器，通過發送訊息的成功失敗來判斷長連接的連接狀態
                    if (!isSuccess) {//長連接已斷開
                        mHandler.removeCallbacks(heartBeatRunnable);
                        mWebSocket.cancel();//取消掉以前的長連接
                        new com.example.mytest.websocket.thread.InitSocketThread().start();//創建一個新的連接
                    } else {//長連接處于連接狀態
                        //長連接處于連接狀態---
                        Log.e("TAG", "發送心跳包-------------長連接處于連接狀態");
                    }

                    sendTime = System.currentTimeMillis();
                }
                mHandler.postDelayed(this, HEART_BEAT_RATE);//每隔一定的時間，對長連接進行一次心跳檢測
            }
        };


    }

}

8.在你想要長連接的地方連接

public class TestActivity extends AppCompatActivity {

	private Intent intent;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test);
        initView();
    }

    private void initView() {
        findViewById(R.id.btn_start).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                start();
            }
        });

        findViewById(R.id.btn_stop).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stop();
            }
        });
    }

    private void start() {
        intent = new Intent(TestActivity.this, BackService.class);
        startService(intent);
        Log.e("TAG", "start----");
    }


    private void stop() {
        stopService(intent);
        Log.e("TAG", "stop----");
    }
}

9.websocket客戶端測驗工具
websocket客戶端測驗工具