2021.1.16更新
适配targetSdkVersion P(28)及更高的版本
项目中若存在判断当前网络类型，一般都会用到如下方法：
/**
* get the network type
*
* @param ctx Context
* @return networktype
*/
public static int getNetWorkType(Context ctx) {
int networkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
TelephonyManager tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
try {
int defaultDataSubId = getSubId();
if (defaultDataSubId == -1) {
networkType = tm.getNetworkType();
} else {
try {
Method dataNetworkType = TelephonyManager.class
.getDeclaredMethod("getDataNetworkType", new Class[]{int.class});
dataNetworkType.setAccessible(true);
networkType = (int) dataNetworkType.invoke(tm, defaultDataSubId);
} catch (Throwable t) {
t.printStackTrace();
}
if (networkType == TelephonyManager.NETWORK_TYPE_UNKNOWN) {
networkType = tm.getNetworkType();
}
}
} catch (Throwable t) {
t.printStackTrace();
}
return networkType;
}
/**
* get data sub id
*
* @return subId
*/
private static int getSubId() {
int defaultDataSubId = -1;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
defaultDataSubId = SubscriptionManager.getDefaultDataSubscriptionId();
}
return defaultDataSubId;
}
至于networkType的取值，可参考TelephonyManager类。
使用上述方法，在5G网络之前都没问题，到5G网络时，查看Android Q源码，发现TelephonyManager类里增加了这么一个类型常量：
/** Current network is NR(New Radio) 5G. */
public static final int NETWORK_TYPE_NR = TelephonyProtoEnums.NETWORK_TYPE_NR; // 20.
意味着在5G网络下上述两个方法返回的networkType应该是20，实际测试了下，然并卵，返回的是13(NETWORK_TYPE_LTE，表示4G)。
是Android系统出问题了？还是厂商定制ROM出问题了？
查看运营商5G网络的搭建，发现现在5G网络基本都是通过4G增强型基站发射，也就是所谓的非独立组网(NSA)，所以系统获取到的是NETWORK_TYPE_LTE，是没错的。只有独立5G组网(SA)，系统才会返回NETWORK_TYPE_NR。
可厂商的手机明明就可以显示5G网络标识，不一致了，怎么搞？
网传华为提供了自己的接口判断是否为5G网络，亲试确实可正常使用，如下代码：
/**
* get huawei network type
*
* @return networkType
*/
public static int getHwNetworkType(Context ctx) {
int networkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
if (VERSION.SDK_INT >= VERSION_CODES.O
&& ctx.checkSelfPermission(permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED) {
try {
TelephonyManager tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
ServiceState ss;
int subId = SubscriptionManager.getDefaultDataSubscriptionId();
if (subId < 0) {
ss = tm.getServiceState();
} else {
Class<TelephonyManager> classTm = TelephonyManager.class;
Method method = classTm
.getDeclaredMethod("getServiceStateForSubscriber", new Class[]{int.class});
method.setAccessible(true);
Object objSs = method.invoke(tm, subId);
ss = (ServiceState) objSs;
}
Method hwGetNetworkMethod = ServiceState.class.getMethod("getHwNetworkType");
hwGetNetworkMethod.setAccessible(true);
Integer hwNetType = (Integer) hwGetNetworkMethod.invoke(ss);
if (hwNetType != null) {
networkType = hwNetType;
}
} catch (Exception e) {
QLog.e(tag, QLog.USR, "getHwNetworkType throw ex", e);
}
}
return networkType;
}
华为的搞定了，其它厂商呢？找了半天没找到类似接口，有点小无奈...
仔细看华为提供的接口，里面用到了ServiceState，在Android Q上此类有getNrState方法，"nr"跟NETWORK_TYPE_NR貌似有点儿像，也许这个方法正确判断5G，但是由于系统限制，此方法无法反射调用。但里面的nrState在toString()方法里面出现了，是不是可以搞事情？于是有了下面通用的方法：
/**
* network util
*/
public class NetworkUtil {
public static final int NETWORK_TYPE_NR = 20;
public static final int SDK_VERSION_Q = 29;
/**
* get the network type
*
* @param ctx Context
* @return networkType
*/
public static int getNetWorkType(Context ctx) {
int networkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
TelephonyManager tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
try {
int defaultDataSubId = getSubId();
if (defaultDataSubId == -1) {
networkType = tm.getNetworkType();
} else {
Object obj = ReflectionUtil.invokeMethod(tm,
"android.telephony.TelephonyManager", "getDataNetworkType",
new Class[]{int.class}, defaultDataSubId);
if (obj instanceof Integer) {
networkType = (Integer) obj;
}
if (networkType == TelephonyManager.NETWORK_TYPE_UNKNOWN) {
networkType = tm.getNetworkType();
}
}
} catch (Throwable t) {
t.printStackTrace();
}
if (networkType == TelephonyManager.NETWORK_TYPE_LTE) {
networkType = adjustNetworkType(ctx, networkType);
}
return networkType;
}
/**
* get the 5G network type
*
* @param ctx Context
* @param networkTypeFromSys this method can be call only when networkTypeFromSys = 13(LET)
* @return correct network type
*/
private static int adjustNetworkType(Context ctx, int networkTypeFromSys) {
int networkType = networkTypeFromSys;
if (VERSION.SDK_INT >= SDK_VERSION_Q
&& ctx.checkSelfPermission(permission.READ_PHONE_STATE)
== PackageManager.PERMISSION_GRANTED) {
try {
TelephonyManager tm = (TelephonyManager) ctx
.getSystemService(Context.TELEPHONY_SERVICE);
ServiceState ss = null;
int defaultDataSubId = getSubId();
if (defaultDataSubId == -1) {
ss = tm.getServiceState();
} else {
Object obj = ReflectionUtil
.invokeMethod(tm, "android.telephony.TelephonyManager",
"getServiceStateForSubscriber", new Class[]{int.class},
defaultDataSubId);
if (obj instanceof ServiceState) {
ss = (ServiceState) obj;
}
if (ss == null) {
ss = tm.getServiceState();
}
}
if (ss != null && isServiceStateFiveGAvailable(ss.toString())) {
networkType = NETWORK_TYPE_NR;
}
} catch (Throwable t) {
t.printStackTrace();
}
}
return networkType;
}
/**
* get data sub id
*
* @return subId
*/
private static int getSubId() {
int defaultDataSubId = -1;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
defaultDataSubId = SubscriptionManager.getDefaultDataSubscriptionId();
}
return defaultDataSubId;
}
/**
* check the service state str is 5G
*
* @param ss services state str
* @return true if is 5G
*/
private static boolean isServiceStateFiveGAvailable(String ss) {
boolean available = false;
if (!TextUtils.isEmpty(ss)
&& (ss.contains("nrState=NOT_RESTRICTED")
|| ss.contains("nrState=CONNECTED"))) {
available = true;
}
return available;
}
}
此方法为通用方法，使用时只需调用NetworkUtil#getNetWorkType(Context)即可，当然前提还得先获取下READ_PHONE_STATE权限，各大厂商皆可用。
上述代码已适配targetSdkVersion P(28)及更高的版本，ReflectionUtil代码可参考这篇文章
