network: Android 网络判断（wifi、3G与其他）

package mark.zeng;   

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 = ; 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() > ;
    }   

    /**
     * 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;
    }