activity_main.xml <? xml version= "1.0" encoding= "utf-8" ?> < LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"     xmlns: app = "http://schemas.android.com/apk/res-auto"     xmlns: tools = "http://schemas.android.com/tools"     android :layout_width= "match_parent"     android :layout_height= "match_parent"     android :orientation= "vertical"     tools :context= "com.arham.csdevbin.downloadimagefrominternet.MainActivity" >     < ImageView         android :id= "@+id/imageView"         android :layout_width= "300dp"         android :layout_height= "400dp"         android :layout_gravity= "center_horizontal"         an...

AsyncTask enables proper and easy use of the UI thread. This class allows you to perform background operations and publish results on the UI thread without having to manipulate threads and/or handlers. AsyncTask is designed to be a helper class around  Thread  and  Handler  and does not constitute a generic threading framework. AsyncTasks should ideally be used for short operations (a few seconds at the most.) If you need to keep threads running for long periods of time, it is highly recommended you use the various APIs provided by the  java.util.concurrent  package such as  Executor ,  ThreadPoolExecutor  and  FutureTask . An asynchronous task is defined by a computation that runs on a background thread and whose result is published on the UI thread. An asynchronous task is defined by 3 generic types, called  Params ,  Progress  and  Result , and 4 steps, called  onPreExecute ,  doInBackground ...