Ho provato a inserire quel codice nel prg

codice:
import javax.swing.*;

public class ConversioniBinHexOct
   {
      public static void main (String args[]) 
         {
          String bin,hex,oct,help;
          int t,i,quoz,resto;
           
          JTextArea outputTextArea = new JTextArea ();
          JScrollPane scroll = new JScrollPane(outputTextArea); 
          
          outputTextArea.append ("Decimale    Binario   Esadecimale   Ottale\n");
          bin="";hex="";oct="";
          resto=2;
          for (i=1; i<=256; i++)
             {
               
               help=""+i; 
               outputTextArea.append(help+"                   ");
                t=i;
                while (t!=0) 
                  {
                     quoz=t/2;
                     resto=t%2;
                     t=quoz;
                     bin=resto+bin;
                   }
               outputTextArea.append ("Bin "+bin+"      ");
               bin="";
               t=i;
                while (t!=0) 
                  {
                     quoz=t/16;
                     resto=t%16;
                     t=quoz;
                     if (resto>9) 
                        {
                          switch (resto) 
                           {
                             case 10: hex="A"+hex; break;
                             case 11: hex="B"+hex; break;
                             case 12: hex="C"+hex; break;
                             case 13: hex="D"+hex; break;
                             case 14: hex="E"+hex; break;
                             case 15: hex="F"+hex; break;
                           }
                        }
                     else  hex=resto+hex;
                   }
               outputTextArea.append ("Hex "+hex+"      ");
                hex="";
                t=i;
                while (t!=0) 
                  {
                     quoz=t/8;
                     resto=t%8;
                     t=quoz;
                     oct=resto+oct;
                   }
               outputTextArea.append ("Oct "+oct);
               oct="";
               outputTextArea.append ("\n");           
              }

JScrollPane jsp = newJScrollPane(outputTextArea);
getContentPane().add(jsp);


JOptionPane.showMessageDialog(null,outputTextArea,"Conversioni",JOptionPane.INFORMATION_MESSAGE);
        System.exit(0);

         }
   }
ma mi dà quest'errore
codice:
 
C:\java\bin>javac ConversioniBinHexOct.java
ConversioniBinHexOct.java:66: cannot resolve symbol
symbol  : method newJScrollPane (javax.swing.JTextArea)
location: class ConversioniBinHexOct
JScrollPane jsp = newJScrollPane(outputTextArea);
                  ^
ConversioniBinHexOct.java:67: cannot resolve symbol
symbol  : method getContentPane ()
location: class ConversioniBinHexOct
getContentPane().add(jsp);
^
2 errors

C:\java\bin>

xchè? :master: