NetWorkUtils.java

package com.cretin.www.cretinautoupdatelibrary.utils;

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

/**
 * Created by cretin on 2017/4/21.
 */

public class NetWorkUtils {
    public static String getCurrentNetType(Context context) {
        String type = "";
        ConnectivityManager cm = ( ConnectivityManager ) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = cm.getActiveNetworkInfo();
        if ( info == null ) {
            type = "null";
        } else if ( info.getType() == ConnectivityManager.TYPE_WIFI ) {
            type = "wifi";
        } else if ( info.getType() == ConnectivityManager.TYPE_MOBILE ) {
            int subType = info.getSubtype();
            if ( subType == TelephonyManager.NETWORK_TYPE_CDMA || subType == TelephonyManager.NETWORK_TYPE_GPRS
                    || subType == TelephonyManager.NETWORK_TYPE_EDGE ) {
                type = "2g";
            } else if ( subType == TelephonyManager.NETWORK_TYPE_UMTS || subType == TelephonyManager.NETWORK_TYPE_HSDPA
                    || subType == TelephonyManager.NETWORK_TYPE_EVDO_A || subType == TelephonyManager.NETWORK_TYPE_EVDO_0
                    || subType == TelephonyManager.NETWORK_TYPE_EVDO_B ) {
                type = "3g";
            } else if ( subType == TelephonyManager.NETWORK_TYPE_LTE ) {// LTE是3g到4g的过渡，是3.9G的全球标准
                type = "4g";
            }
        }
        return type;
    }
}