E/AndroidRuntime:致命异常:AsyncTask #1 java.lang。RuntimeException:在执行doInBackground()时发生错误

I am a beginner in programming and I just want to create an app that display some markers on map using some coordinates from a database( hosted by 000webhost), using PHP and JSON.The map is working, but there are no markers. Please help me because I really cannot figure it out.I am a beginner in programming and I just want