Question

我有这段代码来检查互联网连接是否可用。

    public static boolean  isOnline() {
    Runtime runtime = Runtime.getRuntime();
    try {
        Process ipProcess = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
        int exitValue = ipProcess.waitFor();
        return (exitValue == 0);
    } catch (IOException | InterruptedException e) {
        e.printStackTrace();
    }
    return false;
}

现在我想使用RxJava / RxAndroid执行相同的任务。那我怎么能这样做呢？

Answer 1

如果您被允许使用ConnectivityManager，这是检查互联网连接的快捷方式：

public static Observable<Boolean> isInternetOn(Context context) {
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    return Observable.just(activeNetworkInfo != null && activeNetworkInfo.isConnected());
    }

然后按如下方式使用它：

private Observable<Object> executeNetworkCall() {
    return isInternetOn(context)
            .filter(connectionStatus -> connectionStatus)
            .switchMap(connectionStatus -> doNetworkCall()));
}

如果您需要更多信息，此answer会提供更详细的说明。

Answer 2

您可以使用ReactiveNetwork。这个库可以用于检查引擎盖下的连接状态，您可以通过订阅它来观察连接状态。

Answer 3

public class MainActivity extends AppCompatActivity{
  private Subscription sendStateSubscription;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      final Observable<RxNetwork.State> sendStateStream =
              RxNetwork.stream(this);

      sendStateSubscription = AppObservable.bindActivity(
            this, sendStateStream
      ).subscribe(new Action1<RxNetwork.State>() {
          @Override public void call(RxNetwork.State state) {
              if(state == RxNetwork.State.NOT_CONNECTED)
                  Timber.i("Connection lost");
              else
                  Timber.i("Connected");
          }
      });
  }

  @Override protected void onDestroy() {
      sendStateSubscription.unsubscribe();
      sendStateSubscription = null;

      super.onDestroy();
  }
}

Answer 4

您可以使用 Rx接收器

检查互联网并收听状态

请参阅：https://github.com/f2prateek/rx-receivers

Answer 5

//使用以下代码ping任何网站以检查互联网连接

public boolean isConnected() throws InterruptedException, IOException
{
    String command = "ping -c 1 google.com";
    return (Runtime.getRuntime().exec (command).waitFor() == 0);
}

RxJava / RxAndroid检查互联网连接是否可用

5 个答案: