android - How this error can be resolved? -


the app crashes out click hit button. following things being shown in logcat. posting required files.

here logcat:

08-20 19:10:22.656 6198-6198/com.example.sambal.jasonparsingdemo e/androidruntime: fatal exception: main process: com.example.sambal.jasonparsingdemo, pid: 6198 java.lang.nullpointerexception: attempt invoke virtual method 'void android.widget.textview.settext(java.lang.charsequence)' on null object reference @ com.example.sambal.jasonparsingdemo.mainactivity$1$1.onresponse(mainactivity.java:49) @ com.example.sambal.jasonparsingdemo.mainactivity$1$1.onresponse(mainactivity.java:45) @ com.android.volley.toolbox.stringrequest.deliverresponse(stringrequest.java:60) @ com.android.volley.toolbox.stringrequest.deliverresponse(stringrequest.java:30) @ com.android.volley.executordelivery$responsedeliveryrunnable.run(executordelivery.java:99) @ android.os.handler.handlecallback(handler.java:751) @ android.os.handler.dispatchmessage(handler.java:95) @ android.os.looper.loop(looper.java:154) @ android.app.activitythread.main(activitythread.java:6236) @ java.lang.reflect.method.invoke(native method) @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:891) @ com.android.internal.os.zygoteinit.main(zygoteinit.java:781)

here mainactivity.java:

package com.example.sambal.jasonparsingdemo;  import android.support.v7.app.appcompatactivity; import android.os.bundle; import android.view.view; import android.widget.button; import android.widget.textview;  import com.android.volley.request; import com.android.volley.requestqueue; import com.android.volley.response; import com.android.volley.volleyerror; import com.android.volley.toolbox.stringrequest; import com.android.volley.toolbox.volley;  import java.io.bufferedreader; import java.io.ioexception; import java.io.inputstream; import java.io.inputstreamreader; import java.net.httpurlconnection; import java.net.malformedurlexception; import java.net.url;  public class mainactivity extends appcompatactivity { button btnhit; textview tvdata; string server_url = "http://www.google.com"; @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      btnhit = (button) findviewbyid(r.id.btnhit);      tvdata = (textview) findviewbyid(r.id.jasonitem);      btnhit.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {              final requestqueue requestqueue = volley.newrequestqueue(mainactivity.this);              stringrequest stringrequest = new stringrequest(request.method.get, server_url,                     new response.listener<string>() {                         @override                         public void onresponse(string response) {                              tvdata.settext(response);                             requestqueue.stop();                          }                     }, new response.errorlistener() {                 @override                 public void onerrorresponse(volleyerror error) {                      tvdata.settext("something went wrong....");                     error.printstacktrace();                     requestqueue.stop();                  }             });             requestqueue.add(stringrequest);         }     });   } }

here volley dependency have added. okay used in code?

image description

dependencies:

dependencies { compile filetree(dir: 'libs', include: ['*.jar']) androidtestcompile('com.android.support.test.espresso:espresso-core:2.2.2', {     exclude group: 'com.android.support', module: 'support-annotations' }) compile 'com.android.support:appcompat-v7:25.3.1' compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha7' testcompile 'junit:junit:4.12' compile 'com.android.volley:volley:1.0.0'

while setting data make sure response doesn't have null prevent set condition 

if(!textutils.isempty(response))     tvdata.settext(response);

and make sure xml have correct id tvdata = (textview) findviewbyid(r.id.jasonitem);


Comments

Post a Comment

Popular posts from this blog

ubuntu - PHP script to find files of certain extensions in a directory, returns populated array when run in browser, but empty array when run from terminal -

i running os ububtu 16.04. ultimate goal able run php script cron job every minute. here php script located @ /var/www/html/tests/test/index.php : <?php $directorypath = $_server['document_root']."/tests/test/data/"; echo "directorypath: $directorypath<br><br>";//check $imagefilepathsarray = glob($directorypath . "*.{png,gif}", glob_brace); echo "<br><br>imagefilepathsarray: "; print_r($imagefilepathsarray);//check ?> when open php script in browser visiting url my-ip-address/tests/test/index.php , get: directorypath: /var/www/html/tests/test/data/ imagefilepathsarray:array( [0] => /var/www/html/tests/test/data/pic.png [1] => /var/www/html/tests/test/data/pic.gif ) before writing cron job in crontab file, need check if can run anywhere using terminal . opened ubuntu terminal @ /home/ location, , executed in terminal: sudo php /var/www/html/tests/test/index.php i got following out...
Read more

php - How can i create a user dashboard -

today have questions you, want create user dashboard site, include (obviously), users data, example -email -username -and others stuff how can information, , print them in html page? if can, how can these information via php sessions? shuld use session? example, if user login, , start new session ( session_start() ), how can data print in dashboard? should use php "project"? in advice, have day , thank time!
Read more

javascript - How to detect toggling of the fullscreen-toolbar in jQuery Mobile? -

i have jquery mobile page fixed full-screen toolbar, data-tap-toggle enabled. straight under toolbar have positioned banner should slide upwards when toolbar hiding , slide downward when toolbar showing. jquery mobile toggles toolbar applying , removing ui-fixed-hidden class - sadly, can't find in documentation of toolbar widget toggle , hide or show event that. how can detect when toolbar toggled, reposition banner? .banner { position: fixed; background-color: darkseagreen; top: 46px; min-height: 48px; width: 100%; text-align: center; line-height: 48px; } <!doctype html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no"> <link rel="stylesheet" href="https://code.jquery.com/mobile/1.4.5/jquery.mobile-1.4.5.css"> <script src="https://code.jquery.com/jquery-1....
Read more