这是我解决这个问题的解决方案，并检查有效的互联网连接，因为正如他们所说，网络信息类不能给你预期的结果，它可能会在网络连接但没有互联网时返回true。
所以这是我基于@Levite回答的完整解决方案:
首先，你必须有AsynckTask检查网络可用性，这是我的:
public class Connectivity {
private static final String TAG = "Connectivity";
private static boolean hasConnected = false, hasChecked = false;
private InternetListener internetListener;
private Activity activity;
public Connectivity(InternetListener internetListener, Activity activity) {
this.internetListener = internetListener;
this.activity = activity;
}
public void startInternetListener() {
CheckURL checkURL = new CheckURL(activity);
checkURL.execute();
long startTime = System.currentTimeMillis();
while (true) {
if (hasChecked && hasConnected) {
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
internetListener.onConnected();
}
});
checkURL.cancel(true);
return;
}
// check if time
if (System.currentTimeMillis() - startTime >= 1000) {
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
internetListener.onDisconnected();
}
});
checkURL.cancel(true);
return;
}
}
//return hasConnected;
}
class CheckURL extends AsyncTask<Void, Void, Boolean> {
private Activity activity;
public CheckURL(Activity activity) {
this.activity = activity;
}
@Override
protected Boolean doInBackground(Void... params) {
if (!isNetWorkAvailable(activity)) {
Log.i(TAG, "Internet not available!");
return false;
}
int timeoutMs = 3000;
try {
Socket sock = new Socket();
SocketAddress sockaddr = new InetSocketAddress("8.8.8.8", 53);
sock.connect(sockaddr, timeoutMs);
sock.close();
Log.i(TAG, "Internet available :)");
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
@Override
protected void onPostExecute(Boolean result) {
hasChecked = true;
hasConnected = result;
super.onPostExecute(result);}}
private static final String TAG = "Connectivity";
private static boolean isNetWorkAvailable(Activity activity) {
ConnectivityManager connectivityManager =
(ConnectivityManager)
activity.getSystemService(Activity.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo =
null;
if (connectivityManager != null) {
networkInfo =
connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
}
boolean isConnected;
boolean isWifiAvailable = false;
if (networkInfo != null) {
isWifiAvailable = networkInfo.isAvailable();
}
boolean isWifiConnected = false;
if (networkInfo != null) {
isWifiConnected = networkInfo.isConnected();
}
if (connectivityManager != null) {
networkInfo =
connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
}
boolean isMobileAvailable = false;
if (networkInfo != null) {
isMobileAvailable = networkInfo.isAvailable();
}
boolean isMobileConnected = false;
if (networkInfo != null) {
isMobileConnected = networkInfo.isConnected();
}
isConnected = (isMobileAvailable && isMobileConnected) ||
(isWifiAvailable && isWifiConnected);
return (isConnected);}
}}
private static boolean isNetWorkAvailable(Context context) {
ConnectivityManager connectivityManager =
(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo =
null;
if (connectivityManager != null) {
networkInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
}
boolean isConnected;
boolean isWifiAvailable = false;
if (networkInfo != null) {
isWifiAvailable = networkInfo.isAvailable();
}
boolean isWifiConnected = false;
if (networkInfo != null) {
isWifiConnected = networkInfo.isConnected();
}
if (connectivityManager != null) {
networkInfo =
connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
}
boolean isMobileAvailable = false;
if (networkInfo != null) {
isMobileAvailable = networkInfo.isAvailable();
}
boolean isMobileConnected = false;
if (networkInfo != null) {
isMobileConnected = networkInfo.isConnected();
}
isConnected = (isMobileAvailable && isMobileConnected) ||
(isWifiAvailable && isWifiConnected);
return (isConnected);
}
}
之后，你应该创建另一个线程来启动AscnkTask并使用InternetListener监听结果。
public interface InternetListener {
void onConnected();
void onDisconnected();
}
而等待AsynckTask结果的线程，你可以把它放在Utility类中:
private static Thread thread;
public static void startNetworkListener(Context context, InternetListener
internetListener) {
if (thread == null){
thread = new Thread(new Runnable() {
@Override
public void run() {
Looper.prepare();
new Connectivity(internetListener,context).startInternetListener();
}
});
}
thread.start();
}
最后调用startNetworkListener()方法并监听结果。
My Utils.java类中的activity示例:
Utils.startNetworkListener(this, new InternetListener() {
@Override
public void onConnected() {
// do your work when internet available.
}
@Override
public void onDisconnected() {
// do your work when no internet available.
}
});
快乐编码:)。
