java - AsyncTask in Android with return interface -

i'm using asynctask in android request server , recive data class. know asynctask don't return used code made other people return strings using interface.

here have asynctask class code:

public class webrequest extends asynctask<string, void, string> {  //data public string mfilecontents = "false";  //api-info public webrequestresponse delegate = null;  public webrequest(webrequestresponse asyncresponse) {     delegate = asyncresponse;//assigning call interfacethrough constructor }   @override protected string doinbackground(string... params) {     mfilecontents = downloadfile(params[0]);     if(mfilecontents == null) {         log.d("downloaddata", "error downloading");     }     return mfilecontents; }  protected void oonpostexecute(string result) {     super.onpostexecute(result);     delegate.processfinish(mfilecontents);     log.d("downloaddata", "result was: " + result); //result }  private string downloadfile(string urlpath) {     stringbuilder tempbuffer = new stringbuilder();     try {         url url = new url(urlpath);         httpurlconnection connection = (httpurlconnection) url.openconnection();         int response = connection.getresponsecode();         log.d("downloaddata", "the response code " + response);         inputstream  = connection.getinputstream();         inputstreamreader isr = new inputstreamreader(is);          int charread;         char[] inputbuffer = new char[500];         while(true){             charread = isr.read(inputbuffer);             if(charread <=0) {                 break;             }             tempbuffer.append(string.copyvalueof(inputbuffer, 0, charread));         }          return tempbuffer.tostring();      } catch(ioexception e) {         log.d("downloaddata", "io exception reading data: " + e.getmessage());         e.printstacktrace();     } catch(securityexception e) {         log.d("downloaddata", "security exception. needs permissions? " + e.getmessage());     }     return null; }  } 

now, interface:

public interface webrequestresponse { void processfinish(string output); } 

in sync class have this:

public class api implements webrequestresponse { 

and make execute like:

    public static void startrequest(string url) {     string response = null;     webrequest request = new webrequest(new webrequestresponse() {          @override         public void processfinish(string output) {             test(output); //testing response code         }     });     request.execute(url); } 

the problem code never called , never return anything. using log.d found nothing works here: "delegate.processfinish(mfilecontents);" allocated in asynctask class. doing wrong?

thanks

thanks rucsi, found writting onpostexecute double o