我制作了一个程序,需要使用wifi连接互联网。我找到了一些信息来检查wifi是否已连接。但在某些情况下,你可以连接wifi AP,但仍然无法使用互联网,比如需要账号和密码才能在https中进行认证,或者wifi AP不能连接互联网。那么,我该如何检查真正的互联网连接?
只要对 www.google.com 进行 "Ping",它们宕机的可能性非常低。
P.S. 这是我们应用程序中的做法。
public static boolean isReachable(Context context) {
// First, check we have connectivity
final ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo netInfo = connMgr.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnected()) {
// check if google is reachable
try {
URL url = new URL("http://www.google.com");
HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
urlc.setRequestProperty("Connection", "close");
urlc.setConnectTimeout(10 * 1000); // Ten seconds timeout in milliseconds
urlc.connect();
if (urlc.getResponseCode() == 200) { // success
return true;
} else { // Fail
return false;
}
} catch (IOException e) {
Log.e(TAG, e.getMessage());
return false;
}
} else {
return false;
}
}
创建一个返回布尔值的方法:
ConnectivityManager connectivityManager;
NetworkInfo wifiInfo, mobileInfo;
public Boolean checkNow(Context con){
try{
connectivityManager = (ConnectivityManager) con.getSystemService(Context.CONNECTIVITY_SERVICE);
wifiInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
mobileInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if(wifiInfo.isConnected() || mobileInfo.isConnected())
{
return true;
}
}
catch(Exception e){
System.out.println("CheckConnectivity Exception: " + e.getMessage());
}
return false;
}
将上述方法用于您的onCreate()
方法中,如下所示:
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
boolean con = checkNow(getApplicationContext());
if(con){
Toast.makeText(getApplicationContext(), "Connection Founded", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(getApplicationContext(), "Connection Not Founded", Toast.LENGTH_SHORT).show();
}
}
"Connection Founded"
,否则将提示"Connection Not Founded"
。public boolean isOnline() {
ConnectivityManager conManager =
(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = conManager .getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
return true;
}
return false;
}
请记得在清单文件中获取访问网络状态的权限。<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />