跟网络相关的Android工具类，android工具类, import a

跟网络相关的Android工具类，android工具类, import a

    import android.app.Activity;      import android.content.ComponentName;      import android.content.Context;      import android.content.Intent;      import android.net.ConnectivityManager;      import android.net.NetworkInfo;      //跟网络相关的工具类      public class NetUtils      {          private NetUtils()          {              /* cannot be instantiated */              throw new UnsupportedOperationException("cannot be instantiated");          }          /**          * 判断网络是否连接          *           * @param context          * @return          */          public static boolean isConnected(Context context)          {              ConnectivityManager connectivity = (ConnectivityManager) context                      .getSystemService(Context.CONNECTIVITY_SERVICE);              if (null != connectivity)              {                  NetworkInfo info = connectivity.getActiveNetworkInfo();                  if (null != info && info.isConnected())                  {                      if (info.getState() == NetworkInfo.State.CONNECTED)                      {                          return true;                      }                  }              }              return false;          }          /**          * 判断是否是wifi连接          */          public static boolean isWifi(Context context)          {              ConnectivityManager cm = (ConnectivityManager) context                      .getSystemService(Context.CONNECTIVITY_SERVICE);              if (cm == null)                  return false;              return cm.getActiveNetworkInfo().getType() == ConnectivityManager.TYPE_WIFI;          }          /**          * 打开网络设置界面          */          public static void openSetting(Activity activity)          {              Intent intent = new Intent("/");              ComponentName cm = new ComponentName("com.android.settings",                      "com.android.settings.WirelessSettings");              intent.setComponent(cm);              intent.setAction("android.intent.action.VIEW");              activity.startActivityForResult(intent, 0);          }      }