Java android unable to resolve host

Unable to resolve host » » No address associated with hostname

I tried following this tutorial: Getting Data from the Web

I tried implementing it on Android 3.0, the latest platform for tablets, however, I get this error: «Unable to resolve host «www.anddev.org» No address associated with hostname.«

You can checkout the URL that I used just to prove that the file exists. http://www.anddev.org/images/tut/basic/getdatafromtheweb/loadme.txt

I created a private class and extended it with asynctask. Here is the code:

Any help out there would be appreciated.

11 Answers 11

My bet is that you forgot to give your app the permission to use the internet. Try adding this to your android manifest:

Please, check if you have valid internet connection.

May you have taken permission

BUT

You may have forgot to TURN ON Internet in Mobile or Whatever Device.

Are you able to reach that url from within the built-in browser?

If not, it means that your network setup is not correct. If you are in the emulator, you may have a look at the networking section of the docs.

If you are on OS/X, the emulator is using «the first» interface, en0 even if you are on wireless (en1), as en0 without a cable is still marked as up. You can issue ifconfig en0 down and restart the emulator. I think I have read about similar behavior on Windows.

If you are on Wifi/3G, call your network provider for the correct DNS settings.

Источник

java.net.UnknownHostException: Unable to resolve host » «: No address associated with hostname and End of input at character 0 of

I’ve created an app that loads a question from my web services, and it works fine. But, sometimes it crashes and I do not get the reason why this is happening, especially because I have also given it the required permissions. It works fine, but at random, it crashes and gives me this report.

12 Answers 12

I encountered this problem too, reconnecting the WiFi can solve this.

For us ,we can check if the phone can resolve the host to IP when we start application. If it cannot resolve, tell the user to check the WiFi and then exit.

I hope it helps.

If reconnecting the WiFi doesn’t work for you, try reboot your device.

This works for me. Hope it helps.

I had the same exception in the simulator (Android Studio on OSX) but connecting to the same URL on the iOS simulator worked fine. Looks like it all stemmed from the fact I’d be running the simulator whilst connected to a personal hotspot for my internet connection and then came back later while connected to wifi and the simulator didn’t like the new internet connection for some reason, seems like it thought the old hotspot was the current connection, which was no longer working..

Closing and relaunching the simulator worked!

I got the same error and the issue was that I was on VPN and I didn’t realize it. After disconnecting from the VPN and reconnecting to my WIFI network, the problem was resolved.

Missed to configure tag in manifest file

I encountered this error when running my Android app on my home WiFi, then trying to run it on different WiFi without closing my simulator.

Simply closing the simulator and re-launching the app worked for me!

I had the same problem. java.net.UnknownHostException: Unable to resolve host “”.

I’m running Visual Studio 2019 and Xamarin.

I also switched back to my WiFi but was on a hot spot.

I solved this by clean swiping the emulator. Restore to factory settings. Then re-running visual studio xamarin app which wil redeploy your app again to the fresh emulator.

It worked. I thought I was going to battle for days to solve this. Luckily this post pointed me in the right direction.

I could not understand how it worked perfectly before and then stopped with no code change.

This is my code for reference:

I was testing my application with the Android emulator and I solved this by turning off and turning on the Wi-Fi on the Android emulator device! It worked perfectly.

I was having the same issue, but with Glide. When I was going to disconnect from wifi and reconnect (just like it was suggested here), I noticed that I was in Airplane mode 🤦‍♂️

I had the same problem, but with small difference. I had added NetworkConnectionCallback to check situation when internet connection had changed at runtime, and checking like this before sending all requests:

There can be state like CONNECTING (you can see iе when you turn on wifi, icon starts blinking, after connecting to network, image is static). So, we have two different states: one CONNECT another CONNECTING, and when Retrofit tried to send request internet connection is disabled and it throws UnknownHostException. I forgot to add another type of exception in function which was responsible for sending requests.

It’s just a tricky moment that can by related with this problem.

Источник

Unable to resolve host » » No address associated with host name [closed]

Want to improve this question? Update the question so it’s on-topic for Stack Overflow.

Closed 3 years ago .

In my Android application for reading RSS links, I am getting this error:

java.net.UnknownHostException: Unable to resolve host «example.com»; No address associated with hostname.

In my emulator I can connect to Google through a browser. Please help me to resolve this issue.

17 Answers 17

You probably don’t have the INTERNET permission. Try adding this to your AndroidManifest.xml file, right before :

Note: the above doesn’t have to be right before the tag, but that is a good / correct place to put it.

Note: if this answer doesn’t help in your case, read the other answers!

I’ve seen this problem in the emulator as well. In my case, it is caused by launching the emulator, then putting the computer to sleep or changing the network connection (going from work to home, etc), then attempting to use the same emulator again. Closing and re-launching the emulator resolves the problem in this case.

It is WiFi bug due to wifi disable or not properly connected.

Simply Reconnect the wifi will solve the issue.

Unable to resolve host “”; No address associated with hostname

you must have to check below code here on your manifest :

and most important at least for me:-

enabled wifi connection or internet connection on your mobile device

Sometimes, although you add in the AndroidManifest and you have a WiFi connection, this exception can be thrown. In my case, I have turned off WiFi and then turned it on again. This resolved the error. Weird solution, but sometimes it works.

«» it seems you are trying to resolve this host , which is invalid.

Check for rss URL

Update Following are the possibilities

1 Your browser is configured with proxy, app not

2 Your browser has access to internet. not app

3 can be an SSL issue if URL is secured

I had the same issue. My virtual device was showing a crossed-out WiFi icon at the top bar of the device. I rebooted the virtual device and everything was back to normal.

1- Access to Internet connectivity.

2- The permission for internet is present in the manifest.

3- The url host is valid and registered in a trusted domain name server.

Some times on the emulator, I have to launch the browser before my app can access the Internet.

It could be due to below reasons: —

Either you dont have INTERNET permission in manifest file. If so then please use this statement

Or you are connected to a network but your internet connection is not working. Like you are connected to a Wi-Fi but it doesnt have internet connection or Mobile data on your phone is ON but you dont have data connectivity on your phone.

Point# 2 is interesting and its not assumption, I have tested the same at my end.

Источник

How can I manually trigger a «Unable to resolve host» Exception on an Android Device

I am seeing a spike in these types of errors in my production app via logs:

«Unable to resolve host ««: No address associated with hostname»

The site / API works for 99.9% of people and I am only seeing this intermittently.

It appears as though it is an issue with internet connectivity as per these links:

I have therefore setup some retry logic so that it will make another attempt, but the problem is that I am unsure how to actually intentionally trigger this exception using an Android device (either emulator or live) to see if the new fix works.

How would I go about manually triggering a java.lang.exception where the site I am hitting throws this unable to resolve host issue?

1 Answer 1

You can trigger an UnknownHostException by spelling the host name incorrectly. The cause of the error won’t be the same, but at least you’ll get the same class of exception.

Out there «in the wild» this exception can happen for a number of reasons, including:

• device loses connection to the network during or shortly before host name resolution
• device connects to a captive portal that intercepts DNS requests or is not connected to the Internet
• DNS request fails or times out for any other random reason

DNS request timeouts are a particularly insidious problem. They are difficult to reproduce. The default timeout is way too long, longer than users are willing to wait, and there’s no way to change it. Developers have to resort to hacks like this: Can I set the getaddrinfo timeout in Android for DefaultHttpClient?

Источник

java.net.UnknownHostException: Unable to resolve host [LOCAL]

I use the INTERNET uses-permission in the manifest file.

If I type URL url = new URL(‘http://www.example.com/page’) (remote server) it will work. But if I type URL url = new URL(‘http://example.local/page’) (local server) it will return the error

Now in %WINDIR%/System32/drivers/etc/hosts I wrote this entry :

I can’t use new URL(‘http://10.101.0.179/page’) because example.local is a virtualHost in my apache configuration.

Can’t my AVD looks into the hosts file ? what should I do to tell android to fetch the ip 10.101.0.179 but still send a proper information to apache and tell it to serve the virtual host example.local ?

2 Answers 2

If you try to request a web-page from your local HTTP server and the page is bounded to a virtualHost, so let say you need to reach http://example.local/mypage and if as pointed by @CommonsWare you don’t use mDNS to resolve inter-local domain-names, android will probably throw the same error message as it reads in the title of this question. Here’s the solution I am using :

let’s say http://example.local/mypage refers to the ip address 10.101.0.179 , Android won’t be able to resolve example.local , you need to write the raw url (of your actual local server)

But now when Apache receives this request, unless serving your desired host, 10.101.0.179 won’t be understood in case of a VirtualHost. To round-about this problem, just modify the Host http-header property using setRequestProperty :

Источник