Android 开发工具类 06_NetUtils

跟网络相关的工具类：

1、判断网络是否连接；

2、判断是否是 wifi 连接；

3、打开网络设置界面；

 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);
     }

 }