截至 2020 年 3 月，此答案有更新，支持 API.15 到 API.29，您可以在原始答案之后找到它
回答 2019 年 2 月
检查您是否在线：
boolean isOnline() {
// Checking internet connectivity
ConnectivityManager connectivityMgr = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = null;
if (connectivityMgr != null) {
activeNetwork = connectivityMgr.getActiveNetworkInfo();
}
return activeNetwork != null;
}
科特林：
fun isOnline(): Boolean {
val connectivityMgr = getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
return connectivityMgr.activeNetworkInfo != null
} else {
for (network in connectivityMgr.allNetworks) { // added in API 21 (Lollipop)
val networkCapabilities: NetworkCapabilities? =
connectivityMgr.getNetworkCapabilities(network)
return (networkCapabilities!!.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED) &&
(networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET)))
}
}
return false
}
获取android M之前/之后的互联网连接类型
void internetType() {
// Checking internet connectivity
ConnectivityManager connectivityMgr = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = null;
if (connectivityMgr != null) {
activeNetwork = connectivityMgr.getActiveNetworkInfo();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
NetworkCapabilities nc = connectivityMgr.getNetworkCapabilities(connectivityMgr.getActiveNetwork());
if (nc.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
// connected to mobile data
} else if (nc.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
// connected to wifi
}
} else {
if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
// connected to wifi
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
// connected to mobile data
}
}
}
}
所有情况都需要访问网络状态的权限
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
2020 年 12 月更新
由于NetworkInfo 已被弃用，并且从现在开始API 29，我们必须使用ConnectivityManager.NetworkCallback 及其网络状态更改onAvailable() 和onLost() 回调。
用法：
特点
- 通过在
onDestroy() 方法中进行一些清理来避免内存泄漏，实现 LifecycleObserver 是生命周期意识。
- 它支持从 API 15（冰淇淋三明治）到 API 29 (Android Q)
- 对于 API 21 之前的 API，它使用基于上下文的
BoradcastReceiver 和 NetworkInfo，对于 API 21 及更高版本使用 ConnectivityManager.NetworkCallback。
- 当 WiFi 和蜂窝网络都打开时，连接侦听器不会在 WiFi 断开连接时中断，同时过渡到蜂窝网络。
- 当蜂窝网络开启时，连接监听器不会在 WiFi 已连接且处于活动网络（因为这是首选网络）时中断。
- 如果您要使用该库，则无需包含此权限
android.permission.ACCESS_NETWORK_STATE；但如果要使用实用程序类，则必须包含它。
能力
- 获取当前连接状态（在线/离线）。
- 持续检查/收听互联网连接和
设备离线或在线时触发回调。
- 获取活动互联网连接的类型（WiFi 或蜂窝网络）。
- 获取所有可用网络的类型（WiFi 或蜂窝网络）。 >> 只有
API 21+ 支持
- 获取所有可用网络的数量 >> 仅支持 API 21+
@RequiresApi(api = Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1)
public class ConnectionUtil implements LifecycleObserver {
private static final String TAG = "LOG_TAG";
private ConnectivityManager mConnectivityMgr;
private Context mContext;
private NetworkStateReceiver mNetworkStateReceiver;
/*
* boolean indicates if my device is connected to the internet or not
* */
private boolean mIsConnected = false;
private ConnectionMonitor mConnectionMonitor;
/**
* Indicates there is no available network.
*/
private static final int NO_NETWORK_AVAILABLE = -1;
/**
* Indicates this network uses a Cellular transport.
*/
public static final int TRANSPORT_CELLULAR = 0;
/**
* Indicates this network uses a Wi-Fi transport.
*/
public static final int TRANSPORT_WIFI = 1;
public interface ConnectionStateListener {
void onAvailable(boolean isAvailable);
}
public ConnectionUtil(Context context) {
mContext = context;
mConnectivityMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
((AppCompatActivity) mContext).getLifecycle().addObserver(this);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mConnectionMonitor = new ConnectionMonitor();
NetworkRequest networkRequest = new NetworkRequest.Builder()
.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
.addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
.build();
mConnectivityMgr.registerNetworkCallback(networkRequest, mConnectionMonitor);
}
}
/**
* Returns true if connected to the internet, and false otherwise
*
* <p>
* NetworkInfo is deprecated in API 29
* https://developer.android.com/reference/android/net/NetworkInfo
* <p>
* getActiveNetworkInfo() is deprecated in API 29
* https://developer.android.com/reference/android/net/ConnectivityManager#getActiveNetworkInfo()
* <p>
* getNetworkInfo(int) is deprecated as of API 23
* https://developer.android.com/reference/android/net/ConnectivityManager#getNetworkInfo(int)
*/
public boolean isOnline() {
mIsConnected = false;
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
// Checking internet connectivity
NetworkInfo activeNetwork = null;
if (mConnectivityMgr != null) {
activeNetwork = mConnectivityMgr.getActiveNetworkInfo(); // Deprecated in API 29
}
mIsConnected = activeNetwork != null;
} else {
Network[] allNetworks = mConnectivityMgr.getAllNetworks(); // added in API 21 (Lollipop)
for (Network network : allNetworks) {
NetworkCapabilities networkCapabilities = mConnectivityMgr.getNetworkCapabilities(network);
if (networkCapabilities != null) {
if (networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
networkCapabilities.hasCapability(NET_CAPABILITY_VALIDATED))
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET))
mIsConnected = true;
}
}
}
return mIsConnected;
}
/**
* Returns
* <p> <p>
* <p><p> NO_NETWORK_AVAILABLE >>> when you're offline
* <p><p> TRANSPORT_CELLULAR >> When Cellular is the active network
* <p><p> TRANSPORT_WIFI >> When Wi-Fi is the Active network
* <p>
*/
public int getActiveNetwork() {
NetworkInfo activeNetwork = mConnectivityMgr.getActiveNetworkInfo(); // Deprecated in API 29
if (activeNetwork != null)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
NetworkCapabilities capabilities = mConnectivityMgr.getNetworkCapabilities(mConnectivityMgr.getActiveNetwork());
if (capabilities != null)
if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
// connected to mobile data
return TRANSPORT_CELLULAR;
} else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
// connected to wifi
return TRANSPORT_WIFI;
}
} else {
if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) { // Deprecated in API 28
// connected to mobile data
return TRANSPORT_CELLULAR;
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) { // Deprecated in API 28
// connected to wifi
return TRANSPORT_WIFI;
}
}
return NO_NETWORK_AVAILABLE;
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public int getAvailableNetworksCount() {
int count = 0;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
Network[] allNetworks = mConnectivityMgr.getAllNetworks(); // added in API 21 (Lollipop)
for (Network network : allNetworks) {
NetworkCapabilities networkCapabilities = mConnectivityMgr.getNetworkCapabilities(network);
if (networkCapabilities != null)
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR))
count++;
}
}
return count;
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public List<Integer> getAvailableNetworks() {
List<Integer> activeNetworks = new ArrayList<>();
Network[] allNetworks; // added in API 21 (Lollipop)
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
allNetworks = mConnectivityMgr.getAllNetworks();
for (Network network : allNetworks) {
NetworkCapabilities networkCapabilities = mConnectivityMgr.getNetworkCapabilities(network);
if (networkCapabilities != null) {
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI))
activeNetworks.add(TRANSPORT_WIFI);
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR))
activeNetworks.add(TRANSPORT_CELLULAR);
}
}
}
return activeNetworks;
}
public void onInternetStateListener(ConnectionStateListener listener) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
mNetworkStateReceiver = new NetworkStateReceiver(listener);
IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
mContext.registerReceiver(mNetworkStateReceiver, intentFilter);
} else {
mConnectionMonitor.setOnConnectionStateListener(listener);
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
public void onDestroy() {
Log.d(TAG, "onDestroy");
((AppCompatActivity) mContext).getLifecycle().removeObserver(this);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (mConnectionMonitor != null)
mConnectivityMgr.unregisterNetworkCallback(mConnectionMonitor);
} else {
if (mNetworkStateReceiver != null)
mContext.unregisterReceiver(mNetworkStateReceiver);
}
}
public class NetworkStateReceiver extends BroadcastReceiver {
ConnectionStateListener mListener;
public NetworkStateReceiver(ConnectionStateListener listener) {
mListener = listener;
}
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getExtras() != null) {
NetworkInfo activeNetworkInfo = mConnectivityMgr.getActiveNetworkInfo(); // deprecated in API 29
/*
* activeNetworkInfo.getState() deprecated in API 28
* NetworkInfo.State.CONNECTED deprecated in API 29
* */
if (!mIsConnected && activeNetworkInfo != null && activeNetworkInfo.getState() == NetworkInfo.State.CONNECTED) {
Log.d(TAG, "onReceive: " + "Connected To: " + activeNetworkInfo.getTypeName());
mIsConnected = true;
mListener.onAvailable(true);
} else if (intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, Boolean.FALSE)) {
if (!isOnline()) {
mListener.onAvailable(false);
mIsConnected = false;
}
}
}
}
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public class ConnectionMonitor extends ConnectivityManager.NetworkCallback {
private ConnectionStateListener mConnectionStateListener;
void setOnConnectionStateListener(ConnectionStateListener connectionStateListener) {
mConnectionStateListener = connectionStateListener;
}
@Override
public void onAvailable(@NonNull Network network) {
if (mIsConnected)
return;
Log.d(TAG, "onAvailable: ");
if (mConnectionStateListener != null) {
mConnectionStateListener.onAvailable(true);
mIsConnected = true;
}
}
@Override
public void onLost(@NonNull Network network) {
if (getAvailableNetworksCount() == 0) {
if (mConnectionStateListener != null)
mConnectionStateListener.onAvailable(false);
mIsConnected = false;
}
}
}
}
Kotlin 版本
class ConnectionUtil(var mContext: Context) : LifecycleObserver {
private val TAG = "LOG_TAG"
companion object NetworkType {
/**
* Indicates this network uses a Cellular transport.
*/
const val TRANSPORT_CELLULAR = 0
/**
* Indicates this network uses a Wi-Fi transport.
*/
const val TRANSPORT_WIFI = 1
}
private var mConnectivityMgr: ConnectivityManager? = null
// private var mContext: Context? = null
private var mNetworkStateReceiver: NetworkStateReceiver? = null
/*
* boolean indicates if my device is connected to the internet or not
* */
private var mIsConnected = false
private var mConnectionMonitor: ConnectionMonitor? = null
/**
* Indicates there is no available network.
*/
private val NO_NETWORK_AVAILABLE = -1
interface ConnectionStateListener {
fun onAvailable(isAvailable: Boolean)
}
init {
mConnectivityMgr =
mContext.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
(mContext as AppCompatActivity?)!!.lifecycle.addObserver(this)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mConnectionMonitor = ConnectionMonitor()
val networkRequest = NetworkRequest.Builder()
.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
.addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
.build()
mConnectivityMgr!!.registerNetworkCallback(networkRequest, mConnectionMonitor!!)
}
}
/**
* Returns true if connected to the internet, and false otherwise
*
* NetworkInfo is deprecated in API 29
* https://developer.android.com/reference/android/net/NetworkInfo
*
* getActiveNetworkInfo() is deprecated in API 29
* https://developer.android.com/reference/android/net/ConnectivityManager#getActiveNetworkInfo()
*
* getNetworkInfo(int) is deprecated as of API 23
* https://developer.android.com/reference/android/net/ConnectivityManager#getNetworkInfo(int)
*/
fun isOnline(): Boolean {
mIsConnected = false
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
// Checking internet connectivity
var activeNetwork: NetworkInfo? = null
if (mConnectivityMgr != null) {
activeNetwork = mConnectivityMgr!!.activeNetworkInfo // Deprecated in API 29
}
mIsConnected = activeNetwork != null
} else {
val allNetworks = mConnectivityMgr!!.allNetworks // added in API 21 (Lollipop)
for (network in allNetworks) {
val networkCapabilities = mConnectivityMgr!!.getNetworkCapabilities(network)
if (networkCapabilities != null) {
if (networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
)
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET)
) mIsConnected = true
}
}
}
return mIsConnected
}
/**
* Returns:
*
* NO_NETWORK_AVAILABLE >>> when you're offline
* TRANSPORT_CELLULAR >> When Cellular is the active network
* TRANSPORT_WIFI >> When Wi-Fi is the Active network
*/
fun getActiveNetwork(): Int {
val activeNetwork = mConnectivityMgr!!.activeNetworkInfo // Deprecated in API 29
if (activeNetwork != null) if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
val capabilities = mConnectivityMgr!!.getNetworkCapabilities(
mConnectivityMgr!!.activeNetwork
)
if (capabilities != null) if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
// connected to mobile data
return TRANSPORT_CELLULAR
} else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
// connected to wifi
return TRANSPORT_WIFI
}
} else {
if (activeNetwork.type == ConnectivityManager.TYPE_MOBILE) { // Deprecated in API 28
// connected to mobile data
return TRANSPORT_CELLULAR
} else if (activeNetwork.type == ConnectivityManager.TYPE_WIFI) { // Deprecated in API 28
// connected to wifi
return TRANSPORT_WIFI
}
}
return NO_NETWORK_AVAILABLE
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
fun getAvailableNetworksCount(): Int {
var count = 0
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
val allNetworks = mConnectivityMgr!!.allNetworks // added in API 21 (Lollipop)
for (network in allNetworks) {
val networkCapabilities = mConnectivityMgr!!.getNetworkCapabilities(network)
if (networkCapabilities != null) if (networkCapabilities.hasTransport(
NetworkCapabilities.TRANSPORT_WIFI
)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
) count++
}
}
return count
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
fun getAvailableNetworks(): List<Int> {
val activeNetworks: MutableList<Int> = ArrayList()
val allNetworks: Array<Network> // added in API 21 (Lollipop)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
allNetworks = mConnectivityMgr!!.allNetworks
for (network in allNetworks) {
val networkCapabilities = mConnectivityMgr!!.getNetworkCapabilities(network)
if (networkCapabilities != null) {
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) activeNetworks.add(
TRANSPORT_WIFI
)
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) activeNetworks.add(
TRANSPORT_CELLULAR
)
}
}
}
return activeNetworks
}
fun onInternetStateListener(listener: ConnectionStateListener) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
mNetworkStateReceiver = NetworkStateReceiver(listener)
val intentFilter = IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION)
mContext.registerReceiver(mNetworkStateReceiver, intentFilter)
} else {
mConnectionMonitor!!.setOnConnectionStateListener(listener)
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
fun onDestroy() {
Log.d(TAG, "onDestroy")
(mContext as AppCompatActivity?)!!.lifecycle.removeObserver(this)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (mConnectionMonitor != null) mConnectivityMgr!!.unregisterNetworkCallback(
mConnectionMonitor!!
)
} else {
if (mNetworkStateReceiver != null) mContext.unregisterReceiver(mNetworkStateReceiver)
}
}
inner class NetworkStateReceiver(var mListener: ConnectionStateListener) :
BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
if (intent.extras != null) {
val activeNetworkInfo: NetworkInfo? =
mConnectivityMgr?.getActiveNetworkInfo() // deprecated in API 29
/*
* activeNetworkInfo.getState() deprecated in API 28
* NetworkInfo.State.CONNECTED deprecated in API 29
* */if (!mIsConnected && activeNetworkInfo != null && activeNetworkInfo.state == NetworkInfo.State.CONNECTED) {
mIsConnected = true
mListener.onAvailable(true)
} else if (intent.getBooleanExtra(
ConnectivityManager.EXTRA_NO_CONNECTIVITY,
java.lang.Boolean.FALSE
)
) {
if (!isOnline()) {
mListener.onAvailable(false)
mIsConnected = false
}
}
}
}
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
inner class ConnectionMonitor : NetworkCallback() {
private var mConnectionStateListener: ConnectionStateListener? = null
fun setOnConnectionStateListener(connectionStateListener: ConnectionStateListener?) {
mConnectionStateListener = connectionStateListener
}
override fun onAvailable(network: Network) {
if (mIsConnected) return
Log.d(TAG, "onAvailable: ")
if (mConnectionStateListener != null) {
mConnectionStateListener!!.onAvailable(true)
mIsConnected = true
}
}
override fun onLost(network: Network) {
if (getAvailableNetworksCount() == 0) {
mConnectionStateListener?.onAvailable(false)
mIsConnected = false
}
}
}
}