java - how to use utility class to start intent android -

i updating code company app , there 20 activity classes download pdf , display using code:

public void showpdf() {     file file = new file(environment.getexternalstoragedirectory()+"/pdf/read.pdf");     packagemanager packagemanager = getpackagemanager();     intent testintent = new intent(intent.action_view);     testintent.settype("application/pdf");     list list = packagemanager.queryintentactivities(testintent, packagemanager.match_default_only);     intent intent = new intent();     intent.setaction(intent.action_view);     uri uri = uri.fromfile(file);     intent.setdataandtype(uri, "application/pdf");     startactivity(intent); } 

the code working, has been replicated in 20 classes (seems bad me) , put single class each activity class imports, when try this, things getpackagemanager() , startactivity(intent) no longer work.

how can structure class make happen? or going wrong way.

public class pdfutlity{     public static void showpdf(context context)     {         file file = new file(environment.getexternalstoragedirectory()+"/pdf/read.pdf");         packagemanager packagemanager = context.getpackagemanager();         intent testintent = new intent(intent.action_view);         testintent.settype("application/pdf");         list list = packagemanager.queryintentactivities(testintent, packagemanager.match_default_only);         intent intent = new intent();         intent.setaction(intent.action_view);         uri uri = uri.fromfile(file);         intent.setdataandtype(uri, "application/pdf");         ((activity)context).startactivity(intent);     } }  public class myactivity extends activity{   @override   public void oncreate(bundle savedinstancestate) {       super.oncreate(savedinstancestate);       setcontentview(r.layout.main);       ///.....       pdfutlity.showpdf(this);   } }