android 网络判断

 package mark.zhang;

 import java.util.List;

 import android.content.Context;
 import android.location.LocationManager;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.telephony.TelephonyManager;

 public class NetworkProber {

     /**
      * 网络是否可用
      *
      * @param activity
      * @return
      */
     public static boolean isNetworkAvailable(Context context) {
         ConnectivityManager connectivity = (ConnectivityManager) context
                 .getSystemService(Context.CONNECTIVITY_SERVICE);
         if (connectivity == null) {
         } else {
             NetworkInfo[] info = connectivity.getAllNetworkInfo();
             if (info != null) {
                 for (int i = 0; i < info.length; i++) {
                     if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                         return true;
                     }
                 }
             }
         }
         return false;
     }

     /**
      * Gps是否打开
      *
      * @param context
      * @return
      */
     public static boolean isGpsEnabled(Context context) {
         LocationManager locationManager = ((LocationManager) context
                 .getSystemService(Context.LOCATION_SERVICE));
         List<String> accessibleProviders = locationManager.getProviders(true);
         return accessibleProviders != null && accessibleProviders.size() > 0;
     }

     /**
      * wifi是否打开
      */
     public static boolean isWifiEnabled(Context context) {
         ConnectivityManager mgrConn = (ConnectivityManager) context
                 .getSystemService(Context.CONNECTIVITY_SERVICE);
         TelephonyManager mgrTel = (TelephonyManager) context
                 .getSystemService(Context.TELEPHONY_SERVICE);
         return ((mgrConn.getActiveNetworkInfo() != null && mgrConn
                 .getActiveNetworkInfo().getState() == NetworkInfo.State.CONNECTED) || mgrTel
                 .getNetworkType() == TelephonyManager.NETWORK_TYPE_UMTS);
     }

     /**
      * 判断当前网络是否是wifi网络
      * if(activeNetInfo.getType()==ConnectivityManager.TYPE_MOBILE) { //判断3G网
      *
      * @param context
      * @return boolean
      */
     public static boolean isWifi(Context context) {
         ConnectivityManager connectivityManager = (ConnectivityManager) context
                 .getSystemService(Context.CONNECTIVITY_SERVICE);
         NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();
         if (activeNetInfo != null
                 && activeNetInfo.getType() == ConnectivityManager.TYPE_WIFI) {
             return true;
         }
         return false;
     }

     /**
      * 判断当前网络是否是3G网络
      *
      * @param context
      * @return boolean
      */
     public static boolean is3G(Context context) {
         ConnectivityManager connectivityManager = (ConnectivityManager) context
                 .getSystemService(Context.CONNECTIVITY_SERVICE);
         NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();
         if (activeNetInfo != null
                 && activeNetInfo.getType() == ConnectivityManager.TYPE_MOBILE) {
             return true;
         }
         return false;
     }
 }

另外还有两个方法判断网络是否可用：

 public static boolean isNetworkAvailable_00(Context context) {
         ConnectivityManager cm = ((ConnectivityManager) context
                 .getSystemService(Context.CONNECTIVITY_SERVICE));
         if (cm != null) {
             NetworkInfo info = cm.getActiveNetworkInfo();
             if (info != null && info.isConnectedOrConnecting()) {
                 return true;
             }
         }
         return false;
     }

     public static boolean isNetworkAvailable_01(Context context) {
         ConnectivityManager cm = (ConnectivityManager) context
                 .getSystemService(Context.CONNECTIVITY_SERVICE);
         NetworkInfo network = cm.getActiveNetworkInfo();
         if (network != null) {
             return network.isAvailable();
         }
         return false;
     }

更加严谨的写法：

 public static boolean checkNet(Context context) {

         try {
             ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
             if (connectivity != null) {

                 NetworkInfo info = connectivity.getActiveNetworkInfo();
                 if (info != null && info.isConnected()) {

                     if (info.getState() == NetworkInfo.State.CONNECTED) {
                         return true;
                     }
                 }
             }
         } catch (Exception e) {
         return false;
 }
         return false;
     }