Checking Internet connection in Android

问题

Is there any background task which runs with in application to check for internet connectivity for below scenarios as common ?

1.Start of parsing/fetching data from server

2.In between of parsing/fetching from server

Any sample code or links helps me a lot.

回答1:

You can start an IntentService or Service and use this:

public boolean CheckInternet() 
    {
        ConnectivityManager connec = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        android.net.NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        android.net.NetworkInfo mobile = connec.getNetworkInfo(ConnectivityManager.

        if (wifi.isConnected()) {
            return true;
        } else if (mobile.isConnected()) {
            return true;
        }
        return false;
    }

Also don't forget to add this permission to the AndroidManifest file:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

回答2:

You can use a service for both the tasks.

for the first one, invoke the service, when the downloading is going to start.
Use a thread in the service that is executed after a while that checks for the active internet connection.

Edit-

It could be something like,

Thread thread = new Thread()
{
      @Override
      public void run() {
          try {
              while(true) {
                  sleep(1000);
                  Toast.makeText(getBaseContext(), "Running Thread...", Toast.LENGTH_LONG).show();
                  // Check internet connectivity here
              }
          } catch (InterruptedException e) {
           Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
          }
      }
  };

thread.start();

Have a look at this post also.

Also I have found two other options,

Have a look at Timer Task and Alarm Manager also to check internet connection after a while.

回答3:

You can use the below utility class make sure to give internet permission in manifest.

Let me know if any issues.

private static NetworkUtil mInstance;
private volatile boolean mIsOnline;

private NetworkUtil() {
    ScheduledExecutorService exec = Executors.newSingleThreadScheduledExecutor();
    exec.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            boolean reachable = false;
            try {
                Process process = java.lang.Runtime.getRuntime().exec("ping -c 1 www.google.com");
                int returnVal = process.waitFor();
                reachable = (returnVal==0);
            } catch (Exception e) {
                e.printStackTrace();
            }
            mIsOnline = reachable;
        }
    }, 0, 5, TimeUnit.SECONDS);
}

public static NetworkUtil getInstance() {
    if (mInstance == null) {
        synchronized (NetworkUtil.class) {
            if (mInstance == null) {
                mInstance = new NetworkUtil();
            }
        }
    }
    return mInstance;
}

public boolean isOnline() {
    return mIsOnline;
}

来源：https://stackoverflow.com/questions/14358952/checking-internet-connection-in-android

标签

android

connection

android-internet