先来一个网络状态判断工具类：
public class NetworkUtil {
private NetworkUtil() {
throw new UnsupportedOperationException("u can't instantiate me...");
}
@RequiresPermission("android.permission.ACCESS_NETWORK_STATE")
private static NetworkInfo getActiveNetworkInfo(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
return cm.getActiveNetworkInfo();
}
/**
* 获取当前网络类型
* 需添加权限 {@code <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>}
*/
@RequiresPermission("android.permission.ACCESS_NETWORK_STATE")
public static NetworkType getNetworkType(Context context) {
NetworkType netType = NetworkType.NETWORK_NO;
NetworkInfo info =getActiveNetworkInfo(context);
if (info !=null && info.isAvailable()) {
if (info.getType() == ConnectivityManager.TYPE_WIFI) {
netType = NetworkType.NETWORK_WIFI;
}else if (info.getType() == ConnectivityManager.TYPE_MOBILE) {
switch (info.getSubtype()) {
case TelephonyManager.NETWORK_TYPE_TD_SCDMA:
case TelephonyManager.NETWORK_TYPE_EVDO_A:
case TelephonyManager.NETWORK_TYPE_UMTS:
case TelephonyManager.NETWORK_TYPE_EVDO_0:
case TelephonyManager.NETWORK_TYPE_HSDPA:
case TelephonyManager.NETWORK_TYPE_HSUPA:
case TelephonyManager.NETWORK_TYPE_HSPA:
case TelephonyManager.NETWORK_TYPE_EVDO_B:
case TelephonyManager.NETWORK_TYPE_EHRPD:
case TelephonyManager.NETWORK_TYPE_HSPAP:
netType = NetworkType.NETWORK_3G;
break;
case TelephonyManager.NETWORK_TYPE_LTE:
case TelephonyManager.NETWORK_TYPE_IWLAN:
netType = NetworkType.NETWORK_4G;
break;
case TelephonyManager.NETWORK_TYPE_GSM:
case TelephonyManager.NETWORK_TYPE_GPRS:
case TelephonyManager.NETWORK_TYPE_CDMA:
case TelephonyManager.NETWORK_TYPE_EDGE:
case TelephonyManager.NETWORK_TYPE_1xRTT:
case TelephonyManager.NETWORK_TYPE_IDEN:
netType = NetworkType.NETWORK_2G;
break;
default:
String subtypeName = info.getSubtypeName();
if (subtypeName.equalsIgnoreCase("TD-SCDMA")
|| subtypeName.equalsIgnoreCase("WCDMA")
|| subtypeName.equalsIgnoreCase("CDMA2000")) {
netType = NetworkType.NETWORK_3G;
}else {
netType = NetworkType.NETWORK_UNKNOWN;
}
break;
}
}else {
netType = NetworkType.NETWORK_UNKNOWN;
}
}
return netType;
}
}
网络状态类型枚举类
public enum NetworkType {
NETWORK_WIFI("WiFi"),
NETWORK_4G("4G"),
NETWORK_2G("2G"),
NETWORK_3G("3G"),
NETWORK_UNKNOWN("Unknown"),
NETWORK_NO("No network");
private Stringdesc;
NetworkType(String desc) {
this.desc = desc;
}
@Override
public String toString() {
return desc;
}
}
广播接收者，监听网络---->
public class NetStateChangeReceiverextends BroadcastReceiver {
private NetworkTypemType = NetworkUtil.getNetworkType(MyApplication.getContext());
private static class InstanceHolder{
private static final NetStateChangeReceiverINSTANCE =new NetStateChangeReceiver();
}
private ListmObservers =new ArrayList<>();
@Override
public void onReceive(Context context, Intent intent) {
if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())){
NetworkType networkType = NetworkUtil.getNetworkType(context);
notifyObservers(networkType);
}
}
public static void registerReceiver(Context context){
IntentFilter intentFilter =new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
context.registerReceiver( InstanceHolder.INSTANCE,intentFilter);
}
public static void unRegisterReceiver(Context context){
context.unregisterReceiver( InstanceHolder.INSTANCE);
}
public static void registerObserver(NetStateChangeObserver observer){
if (observer ==null) {
return;
}
if (!InstanceHolder.INSTANCE.mObservers.contains(observer)){
InstanceHolder.INSTANCE.mObservers.add(observer);
}
}
public static void unRegisterObserver(NetStateChangeObserver observer){
if (observer ==null) {
return;
}
if (InstanceHolder.INSTANCE.mObservers ==null) {
return;
}
InstanceHolder.INSTANCE.mObservers.remove(observer);
}
private void notifyObservers(NetworkType networkType){
if (mType == networkType) {
return;
}
mType = networkType;
if (networkType == NetworkType.NETWORK_NO){
for (NetStateChangeObserver observer :mObservers){
observer.onNetDisconnected();
}
}else {
for (NetStateChangeObserver observer :mObservers){
observer.onNetConnected(networkType);
}
}
}
}
需要用到一个观察者，来通知网络状态更新------>
public interface NetStateChangeObserver {
void onNetDisconnected();
void onNetConnected(NetworkType networkType);
}
activity 公共基类注册广播，注册观察者
