httpresponse - can not send response message from httpserver created using java -

i creating httpserver in application, using:

httpserver server = httpserver.create(new inetsocketaddress(8000), 0); 

this server first send response message using

outputstream os = httpex.getresponsebody(); os.write(("your request being handled, please wait").getbytes()); 

and opens 1 jfilechooser. if goes wrong throw error using

os.write(("failed handle request").getbytes()); 

when application runs on user's machine, creates httpserver properly, find through logs when user sends request server, nothing happens. displays blank page. when remove os.write lines works fine , displays filechooser pop-up. not aware going wrong. please me on this. have tried these approaches:

try {                        os.write(("your request being handled, please wait").getbytes());             os.close();             //code open jfilechooser pop-up          } catch (exception e) {             os.write(("failed handle request because"+e.getmessage()).getbytes());             os.close();} 

and

    try {                            os.write(("your request being handled, please wait").getbytes());                  //code open jfilechooser pop-up              } catch (exception e) {                 os.write(("failed handle request because"+e.getmessage()).getbytes());                 }  os.close(); 

solved it. have added os.flush(); as:

finally(){ os.flush(); os.close(); is.close(); httpex.close();  }