java.net.UnknownHostException :“호스트를 확인할 수 없습니다.

java.net.UnknownHostException :“호스트를 확인할 수 없습니다.”: 호스트 이름과 연관된 주소가 없으며 문자 0에서 입력 끝

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내 웹 서비스에서 질문을로드하는 앱을 만들었는데 제대로 작동합니다. 그러나 때로는 충돌이 발생하고 특히 필요한 권한을 부여했기 때문에 이것이 발생하는 이유를 알 수 없습니다. 잘 작동하지만 무작위로 충돌하고이 보고서를 제공합니다.

private void sendContinentQuestions(int id) {
    // TODO Auto-generated method stub

    //Get the data (see above)
    JSONArray json = getJSONfromURL(id);
        try{
            for(int i=0; i < json.length(); i++) {
                HashMap<String, String> map = new HashMap<String, String>();
                JSONObject jObject = json.getJSONObject(i);
                longitude":"72.5660200"
                String category_id = jObject.getString("category_id");
                String question_id = jObject.getString("question_id");
                String question_name = jObject.getString("question_name");
                String latitude = jObject.getString("latitude");
                String longitude = jObject.getString("longitude");
                String answer = jObject.getString("answer");
                String ansLatLng = latitude+"|"+longitude ; 
                Log.v("## data:: ###",question_id+"--"+question_name+"-cat id-"+category_id+"--ansLatLng "+ansLatLng+" answer: "+answer);

                all_question.add(new QuestionData(game_id,category_id,question_id,question_name,ansLatLng,answer));
            }
        }catch(JSONException e)        {
            Log.e("log_tag", "Error parsing data "+e.toString());
        }
    }


}
 public JSONArray getJSONfromURL(int id){

    String response = "";
    URL url;
    try {
        url = new URL(Consts.GET_URL+"index.php/Api/getQuestion?cat_id="+id);
        HttpURLConnection http = (HttpURLConnection) url.openConnection();
        http.setRequestMethod("POST");
        InputStream is = http.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        response = br.readLine();
        Log.v("###Response :: ###",response);
        http.disconnect();
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }catch (ProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace(); 
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } 
    //try parse the string to a JSON object
    JSONArray jArray = null;
    try{

        jArray = new JSONArray(response);

    }catch(JSONException e){
        Log.e("log_tag", "Error parsing data "+e.toString());
    }

    return jArray;
}

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11-13 15:02:52.307: W/System.err(8012): java.net.UnknownHostException: Unable to resolve host "www.xyz.com": No address associated with hostname
11-13 15:02:52.317: W/System.err(8012):     at java.net.InetAddress.lookupHostByName(InetAddress.java:424)
11-13 15:02:52.317: W/System.err(8012):     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
11-13 15:02:52.317: W/System.err(8012):     at java.net.InetAddress.getAllByName(InetAddress.java:214)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282)
11-13 15:02:52.317: W/System.err(8012):     at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177)
11-13 15:02:52.327: W/System.err(8012):     at com.abc.xyz.ContinentActivity.getJSONfromURL(ContinentActivity.java:400)
11-13 15:02:52.327: W/System.err(8012):     at com.abc.xyz.ContinentActivity.sendContinentQuestions(ContinentActivity.java:327)
11-13 15:02:52.327: W/System.err(8012):     at com.abc.xyz.ContinentActivity.access$2(ContinentActivity.java:323)
11-13 15:02:52.327: W/System.err(8012):     at com.abc.xyz.ContinentActivity$LoadQuestions.doInBackground(ContinentActivity.java:254)
11-13 15:02:52.327: W/System.err(8012):     at com.abc.xyz.ContinentActivity$LoadQuestions.doInBackground(ContinentActivity.java:1)
11-13 15:02:52.327: W/System.err(8012):     at android.os.AsyncTask$2.call(AsyncTask.java:287)
11-13 15:02:52.327: W/System.err(8012):     at java.util.concurrent.FutureTask.run(FutureTask.java:234)
11-13 15:02:52.327: W/System.err(8012):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
11-13 15:02:52.327: W/System.err(8012):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
11-13 15:02:52.337: W/System.err(8012):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
11-13 15:02:52.337: W/System.err(8012):     at java.lang.Thread.run(Thread.java:841)
11-13 15:02:52.337: W/System.err(8012): Caused by: libcore.io.GaiException: getaddrinfo failed: EAI_NODATA (No address associated with hostname)
11-13 15:02:52.337: W/System.err(8012):     at libcore.io.Posix.getaddrinfo(Native Method)
11-13 15:02:52.337: W/System.err(8012):     at libcore.io.ForwardingOs.getaddrinfo(ForwardingOs.java:61)
11-13 15:02:52.337: W/System.err(8012):     at java.net.InetAddress.lookupHostByName(InetAddress.java:405)
11-13 15:02:52.337: W/System.err(8012):     ... 24 more
11-13 15:02:52.337: E/log_tag(8012): Error parsing data org.json.JSONException: End of input at character 0 of 
11-13 15:02:52.337: W/dalvikvm(8012): threadid=194: thread exiting with uncaught exception (group=0x417c1700)
11-13 15:02:52.337: E/AndroidRuntime(8012): FATAL EXCEPTION: AsyncTask #5
11-13 15:02:52.337: E/AndroidRuntime(8012): java.lang.RuntimeException: An error occured while executing doInBackground()
11-13 15:02:52.337: E/AndroidRuntime(8012):     at android.os.AsyncTask$3.done(AsyncTask.java:299)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.util.concurrent.FutureTask.run(FutureTask.java:239)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.lang.Thread.run(Thread.java:841)
11-13 15:02:52.337: E/AndroidRuntime(8012): Caused by: java.lang.NullPointerException
11-13 15:02:52.337: E/AndroidRuntime(8012):     at com.abc.xyz.ContinentActivity.sendContinentQuestions(ContinentActivity.java:328)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at com.abc.xyz.ContinentActivity.access$2(ContinentActivity.java:323)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at com.abc.xyz.ContinentActivity$LoadQuestions.doInBackground(ContinentActivity.java:254)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at com.abc.xyz.ContinentActivity$LoadQuestions.doInBackground(ContinentActivity.java:1)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at android.os.AsyncTask$2.call(AsyncTask.java:287)
11-13 15:02:52.337: E/AndroidRuntime(8012):     at java.util.concurrent.FutureTask.run(FutureTask.java:234)

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이 문제도 발생했습니다. WiFi를 다시 연결하면이 문제를 해결할 수 있습니다.

우리는 응용 프로그램을 시작할 때 전화가 호스트를 IP로 확인할 수 있는지 확인할 수 있습니다. 문제가 해결되지 않으면 사용자에게 WiFi를 확인한 다음 종료하라고 안내합니다.

도움이되기를 바랍니다.

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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!

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

This works for me. Hope it helps.

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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.

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Missed to configure tag in manifest file

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

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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!

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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.

ReferenceURL : https://stackoverflow.com/questions/19951466/java-net-unknownhostexception-unable-to-resolve-host-url-no-address-associ