I have get UnknownhostException in parsing JSON data from server,
My URL working on :
http://jsonlint.com
on real device browser(data plan only)
Sometimes its working on PC browser and sometimes not.
Actually I have get the wifi issue, Sometimes its working on wifi connection, when its not, I have restarted my wifi and its worked, and after some time the same issue came,
I want to get the permanent solution for this wifi connection issue, Restarting the Wifi is never a solution on the application user side,
What is the exact problem and solution also...
Usually the UnknownHostException fires when you cannot resolve the DNS record of the URL you've provided. There's a reasonable timeout for that operation, but if you have a weak WiFi connection or you don't have enough signal on your device, the communication can be interrupted in the middle between sending and receiving the response, so your device doesn't receive the response, thus it thinks it's a DNS timeout.
There are 2 things you can try:
Increase the timeout of the response. This will not help, though, if your communication gets interrupted you already sent the query.
Use the IP address instead:
shut-up#i-kill-you:~$ ping jsonlint.com
PING jsonlint.com (54.243.171.164) 56(84) bytes of data.
WifiManager wifiManager = (WifiManager)getSystemService(Context.WIFI_SERVICE);
int linkSpeed = wifiManager.getConnectionInfo().getRssi();
System.out.println("Link Speed is======"+linkSpeed);
It will give u wifi speed so just mention one speed if that speed come then only do next work
Related
In my Android app, I do poll a device (Wallbox) every 5 seconds using the Volley library. For one customer, I get
java.net.NoRouteToHostException: Address not available
after several hours. Usually, using the exactly same type of device and at my place, this polling works for days, but not at (at least) this customer.
The device address is on the local LAN.
I have not found any description about "address not available" that might apply to my case, or at least I did not see the point.
The call is always the same:
http://192.168.160.152/api/status
As this is live data, I set ".setShouldCache(false)" for the request.
Meanwhile, other HTTP requests (in this case, a query to a WWW address, also polled continuously), even using Volley, continue to work:
https://backend.powerfox.energy/api/2.0/my/***********/current
The connection works again after rebooting the device (and at the same original IP address), so I guess it has nothing to do with the wallbox or the router.
And if the wallbox would be not available, I assue I would get "unreachable" error or such.
Is there someone who can help me, what could cause that exception ("address not available"), and what can I do about it?
I know similar questions have been asked but this one is slightly different.
We have an app that does some HTTP connectivity with our server.
While running the app on an LG Nexus 5X or Sumsung Galaxy 5, using any of our 3 WiFi routers, the connection times out ("SocketTimeoutException: timeout" due to "SocketException: Socket closed").
The connection doesn't timeout if we use cellular network, tethering between devices or the simulator on a laptop connected to the same (problematic) WiFi routers.
Just to point out, the routers are connected to different ISPs.
Did anyone ever experience anything like it or have an idea?
Thanks
SOLVED: Trying a GET instead of a POST (with a JSON body of ~4K bytes) seemed to work fine. So, after a session with tcpdump, server side, it turned out that the request does reach the server but it's "corrupted". The first ~300 bytes and the last ~1000 bytes do reach the server but the middle ~2500 bytes are missing (could be due to some service provider infrastructure/ shaper or whatever).
In any case, lowering the buffer size of the OKHttpClient instance (providing it with a new SocketFactory) to 512, did the trick.
Thanks to all of those who tried to assist.
I am building an android app that exchanges data with our server through http api calls. In many cases users are complaining that the app is slow or doesn't work at all.
The most common cause of that is bad network connectivity (low 3g/wifi signal or congested public wifi).
What is the best way to detect bad connections? Once i can detect bad connectivity an icon or toast message can be used to inform the user about the situation.
I am using HttpUrlConnection for the api calls.
I think you can make use of ConnectivityManager. Call getActiveNetworkInfo() and then call getDetailedState() on the NetworkInfo object received. You can check the state of the connection and whether it is VERIFYING_POOR_LINK, though I don't know in which conditions this state is active.
Also you might want to listen to network changes as described in Detect Connection Changes.
I'd probably use latency. Save the time when you get the request, and when the request finishes. If you're seeing numbers that are too high, pop up the warning. If you're downloading large files, you may wish to switch to throughput (how many kbps you're transfering).
as far as i remember http is "connectionless"..
you should try concentrating on minimizing the size of your traffic.. (compress, divide.. etc)
if you really want to test connectivity i guess you should do pings.. every x seconds.. then if the ping is bad you could warn the user..
I tried connecting to an IP address (e.g. http://222.222.222.222:8080) and a URL (e.g. http://www.website.com) while my wiFi is disabled. I noticed that if I don't have a wiFi and I tried connecting to an IP address, it gives me a ConnectException error. On the other hand, if I don't have a wiFi and I tried connecting to a URL, it gives me an IOException error. Why am I receiving different Exception for the 2 cases when the only difference is I supplied an IP address for the first one and a URL for the other? Can someone enlighten me on this one? I am asking this for clarification.
Thank you!
You're getting different errors because different steps are failing.
When you're trying to connect to port 80 of an IP address, it is a connect(2) system call that is failing. There are many different reasons why connect(2) could fail; you'll need to inspect the message from the exception to provide a good error message to the user.
When you're trying to connect to port 80 of a textual address, the libraries will first try to resolve the hostname into an IP address using getaddrinfo(3). The name resolution may or may not fail based on having network access -- if you were trying to connect to localhost, for example, no network access is usually required, as the nameservice lookup can be handled entirely on the local device. Because the nameservice failure happens because you cannot contact a nameserver, it makes sense to give a different error message (and exception), even if the underlying cause is the same for a given set of tests. You might not be able to contact the nameservers for any variety of reasons. Again, you'll need to inspect the message from the exception to give a good error message to the user.
I have a simple app that periodically sends HTTP_GET requests to a server. When sending requests over 3G, I noticed that the requests sometimes time out (and the server-side logging shows that it NEVER receives the request either).
After trying out different combinations I found one consistant pattern when this problem occures (it times out after every 5-15 successful requests).
- TelephonyRegistry: notifyDataConnection() state=2isDataConnectivityPossible()true, reason=null
- TelephonyRegistry: broadcastDataConnectionStateChanged() state=CONNECTEDtypes=default supl, interfaceName=rmnet0
- NetworkLocationProvider: onDataConnectionStateChanged 3
According to Google, NetworkLocationProvider is changed to 'DATA_SUSPENDED', which implies "connection is up, but IP traffic is temporarily unavailable". (see TelephonyManager). On the situations where HTTP_GET requests succeeds, the state is changed to '8'. My app doesn't use the location manage and I've shut down every other non-critical app from running!
I want to know:
What is the cause of this issue? Why does the connection status go to DATA_SUSPENDED?
Is it possible to avoid/overcome this problem?
Any help/insight into this is much appreciated! Thanks in advance!
I have the same problem with my app running on an Huawei IDEOS X3 with Android 2.3.5. The app sends data each minute to a server using HttpClient.
Using logcat I can see that the data connection is lost and then reestablished after a short while. Previously my app stopped working since it tried to send data without a connection causing an exception which was not properly handed.
I don't know the reason for the intermittently dropped data connection but I now handle the situation by checking if there is a data connection prior to sending the data. In my case it does not matter if some data is never sent. If it was important to avoid data loss, I could buffer the data and send it once the connection was back.
public Boolean isDataConnection() {
TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
return tm.getDataState() == TelephonyManager.DATA_CONNECTED;
}