Android prepare Resume Ability to download manager -

this below code simple download manager , i'm trying add resume ability that. @daniel nugent share code.

public class mainactivity extends actionbaractivity {     private imageview image;     private bitmap bmp;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          image = (imageview) findviewbyid(r.id.imageview);          new postasync().execute();     }     @override     protected void onresume() {         super.onresume();         //put on resume functionality here....     }     @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.menu_main, menu);         return true;     }      @override     public boolean onoptionsitemselected(menuitem item) {         // handle action bar item clicks here. action bar         // automatically handle clicks on home/up button, long         // specify parent activity in androidmanifest.xml.         int id = item.getitemid();          //noinspection simplifiableifstatement         if (id == r.id.action_settings) {             return true;         }         return super.onoptionsitemselected(item);     }     class postasync extends asynctask<string, string, integer> {          private progressdialog pdialog;          private static final string sourcepath = "http://www.planwallpaper.com/static/images/supranatural-3d-wallpaper-images.jpg";         @override         protected void onpreexecute() {             pdialog = new progressdialog(mainactivity.this);             pdialog.setmessage("attempting download...");             pdialog.setindeterminate(false);             pdialog.setcancelable(true);             pdialog.show();         }         @override         protected integer doinbackground(string... args) {             int filesize = 0;             try {                 url url = new url(sourcepath);                 httpurlconnection connection = (httpurlconnection) url.openconnection();                 connection.setrequestmethod("get");                 connection.connect();                 filesize = connection.getcontentlength();                 inputstream inputstream = connection.getinputstream();                 bmp = bitmapfactory.decodestream(inputstream);                 inputstream.close();                 connection.disconnect();             } catch (exception e) {                 e.printstacktrace();             }             return filesize;         }         protected void onpostexecute(integer filesize) {             pdialog.dismiss();             mainactivity.this.image.setimagebitmap(bmp);             toast.maketext(mainactivity.this, "file size: " +  filesize, toast.length_long).show();         }     } } 

i dont find document prepare resume ability download manager. please me

i'm trying use way prepare resume download ability error , can not it:

httpclient httpclient = new defaulthttpclient(); httpcontext localcontext = new basichttpcontext(); httpget httpget = new httpget(downloadpath); httpresponse response = httpclient.execute(httpget, localcontext);  final int filesize = connection.getcontentlength();  file file = new file(filepath); int downloaded = 0; if (file.exists()) {     downloaded = (int) file.length();     connection.setrequestproperty("range", "bytes="+(file.length())+"-"); }else{     connection.setrequestproperty("range", "bytes=" + downloaded + "-"); }