想要实现当连接需要验证类的WiFi时，打开浏览器功能最主要的是如何判断连接的wifi是需要验证的。
在网上搜和自己看原码终于找到了。
在frameworks/base/services/core/java/com/android/server/connectivity/NetworkMonitor.java 中有个isCaptivePortal（）方法，可以模仿它改写成我们需要的。
第一步———注册一个广播监听wifi连接

public class WifiBroadCast extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action == ConnectivityManager.CONNECTIVITY_ACTION) {
           Intent serviceIntent = new Intent(context,CheckWifiPortalService.class);
           context.startService(serviceIntent);
        }
    }
}

第二步——监听到wifi连接时开启一个服务检测是否为需要验证wifi
第三步——服务中连接一个返回值204的网址，来判断是否需要验证

public class CheckWifiPortalService extends Service {

   public CheckWifiPortalService(){}

   @Override
   public IBinder onBind(Intent arg0) {
        return null;
   }

   @Override
   public int onStartCommand(Intent intent, int flags, int startId) {
        new Thread(){
            public void run(){
                if (isWifiSetPortal()) {
                   Intent i = new Intent();
                   i.setAction("android.intent.action.VIEW");
                   i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                   Uri content_url = Uri.parse("http://www.baidu");
                   i.setData(content_url);
                   getApplicationContext().startActivity(i);
                }
            }
        }.start();
        return super.onStartCommand(intent, flags, startId);
   }
private boolean isWifiSetPortal() {
        final String mWalledGardenUrl = "http://g/generate_204";
        final int WALLED_GARDEN_SOCKET_TIMEOUT_MS = 10000;

        HttpURLConnection urlConnection = null;
        try {
            URL url = new URL(mWalledGardenUrl);
            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setInstanceFollowRedirects(false);
            urlConnection.setConnectTimeout(WALLED_GARDEN_SOCKET_TIMEOUT_MS);
            urlConnection.setReadTimeout(WALLED_GARDEN_SOCKET_TIMEOUT_MS);
            urlConnection.setUseCaches(false);
            urlConnection.getInputStream();
            return urlConnection.getResponseCode() != 204;
        } catch (IOException e) {
            return false;
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
        }
    }
}

若为需要验证打开浏览器即可。
http://g/generate_204内容为空，如果访问成功则返回204

想要实现当连接需要验证类的WiFi时，打开浏览器功能最主要的是如何判断连接的wifi是需要验证的。
在网上搜和自己看原码终于找到了。
在frameworks/base/services/core/java/com/android/server/connectivity/NetworkMonitor.java 中有个isCaptivePortal（）方法，可以模仿它改写成我们需要的。
第一步———注册一个广播监听wifi连接

public class WifiBroadCast extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action == ConnectivityManager.CONNECTIVITY_ACTION) {
           Intent serviceIntent = new Intent(context,CheckWifiPortalService.class);
           context.startService(serviceIntent);
        }
    }
}

第二步——监听到wifi连接时开启一个服务检测是否为需要验证wifi
第三步——服务中连接一个返回值204的网址，来判断是否需要验证

public class CheckWifiPortalService extends Service {

   public CheckWifiPortalService(){}

   @Override
   public IBinder onBind(Intent arg0) {
        return null;
   }

   @Override
   public int onStartCommand(Intent intent, int flags, int startId) {
        new Thread(){
            public void run(){
                if (isWifiSetPortal()) {
                   Intent i = new Intent();
                   i.setAction("android.intent.action.VIEW");
                   i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                   Uri content_url = Uri.parse("http://www.baidu");
                   i.setData(content_url);
                   getApplicationContext().startActivity(i);
                }
            }
        }.start();
        return super.onStartCommand(intent, flags, startId);
   }
private boolean isWifiSetPortal() {
        final String mWalledGardenUrl = "http://g/generate_204";
        final int WALLED_GARDEN_SOCKET_TIMEOUT_MS = 10000;

        HttpURLConnection urlConnection = null;
        try {
            URL url = new URL(mWalledGardenUrl);
            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setInstanceFollowRedirects(false);
            urlConnection.setConnectTimeout(WALLED_GARDEN_SOCKET_TIMEOUT_MS);
            urlConnection.setReadTimeout(WALLED_GARDEN_SOCKET_TIMEOUT_MS);
            urlConnection.setUseCaches(false);
            urlConnection.getInputStream();
            return urlConnection.getResponseCode() != 204;
        } catch (IOException e) {
            return false;
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
        }
    }
}

若为需要验证打开浏览器即可。
http://g/generate_204内容为空，如果访问成功则返回204