Pretty easy for you, very annoying for me. Some help please

This is part of the code:

import java.applet.Applet;
import java.applet.*;
import javax.swing.*;
//import java.awt.Graphics;
//import java.awt.Color;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.text.*;
import java.util.*;


public class ArticleInterface extends Applet implements ActionListener, ItemListener
{
//globale variabler UI
private Button btHeadline;                   
private Button btPictureText;             
private Button btText;                   
private Button btSource;            
private Button btDate;                  
private TextField tfHeadline;             
private TextArea taPictureText;
private TextArea taText;                   
private TextField tfSource;                  
private String Headline;                  
private String PictureText;            
private String Text;                         
private Button btShow;                  
private TextField tfFilename;            
private ImageCanvas c;                        
private Checkbox chkPri;                  
//Globale variabler JDBC
String databaseURL, databaseName;
Connection con;
public static Statement stmt;
public static ResultSet rs;
public static ResultSetMetaData rsmd;

private String username;
private String password;

  public void init()
  {
      //setter farger og layout for applet
      setBackground(Color.lightGray);
      setLayout(null);

      //oppretter et grafikkpanel
      Panel p = new Panel();


//oppretter grafikkobjekter til panelet
//Tekstdel
btHeadline = new Button("Skriv Overskrift");
btPictureText = new Button("Skriv Intro");
btText = new Button("Skriv Brødtekst");
btSource = new Button("Kilde");
btDate = new Button("Sett dato");
tfHeadline = new TextField(20);
tfSource = new TextField(20);
taPictureText = new TextArea("",5,10,TextArea.SCROLLBARS_VERTICAL_ONLY);
      taText = new TextArea("",5,10,TextArea.SCROLLBARS_VERTICAL_ONLY);
      chkPri = new Checkbox("Prioritert");

//oppretter fonter
Font fontHeadLine = new Font("Areal", Font.BOLD, 20);
Font fontPictureText = new Font("Areal", Font.BOLD, 12);

//Bildedel
btShow = new Button("Vis Bilde");
tfFilename = new TextField(20);
c = new ImageCanvas();


//plasserer grafikkobjekter til panelet
//knapper
p.add(btHeadline);
btHeadline.setBounds(50,50,100,30);

p.add(btPictureText);
btPictureText.setBounds(50,150,100,30);

p.add(btText);
btText.setBounds(50,380,100,30);

p.add(btSource);
btSource.setBounds(50,610,100,30);

//tekstfelt
p.add(tfHeadline);
tfHeadline.setBounds(250,50,200,30);
tfHeadline.setFont(fontHeadLine);

p.add(taPictureText);
taPictureText.setBounds(250,150,200,200);
taPictureText.setFont(fontPictureText);

p.add(taText);
taText.setBounds(250,380,200,200);

p.add(tfSource);
tfSource.setBounds(250,610,200,30);
//Bildedel
p.add(c);
c.setBackground(Color.gray);
c.setBounds(600,50,180,200);

p.add(btShow);
btShow.setBounds(600,300,100,30);
p.add(tfFilename);
tfFilename.setBounds(750,300,200,30);

p.add(btDate);
btDate.setBounds(600,360,100,30);
//Checkboxer
p.add(chkPri);
chkPri.setBounds(600,420,100,30);



//plasserer panelet i framen uten layout
add(p);
p.setLayout(null);
p.setBounds(0,0,1024,768);



//initialiserer listener
btHeadline.addActionListener(this);
btPictureText.addActionListener(this);
btText.addActionListener(this);
btShow.addActionListener(this);
btDate.addActionListener(this);
tfFilename.addActionListener(this);
chkPri.addItemListener(this);
  }

//ActionEvent handler
public void actionPerformed(ActionEvent e)
{
String actionCommand = e.getActionCommand();
if ((e.getSource() instanceof Button) || (e.getSource() instanceof TextField))
{
if (actionCommand.equals("Skriv Overskrift"))
{
                  
      Headline = tfHeadline.getText();
      System.out.println(Headline);
}
else if (actionCommand.equals("Skriv Bildetekst"))
{
//setter fonter,linjeskift,størrelse
PictureText = taPictureText.getText();

}
else if (actionCommand.equals("Skriv Artikkel"))
            {
//setter fonter,linjeskift,størrelse
      Text = taText.getText();
            }
else if (actionCommand.equals("Sett Dato"))
            {
//set date
Date currentDate = new Date();
DateFormat fmt = getDateInstance(Locale.SHORT);
                                             //ERROR!!!!!
String formatert = fmt.format(currentDate);

            }

else if (actionCommand.equals("Vis Bilde") || (e.getSource() instanceof TextField))
            {
                  displayImage();
            }

        }

      }
public void ItemStateChange(ItemEvent e)
{
if (e.getSource() instanceof Checkbox)
{
boolean b = chkPri.getState();      //sjekker om sjekkboks er satt
if (b = true)
System.out.println("1");
else
System.out.println("0");
            }
      }

When i run this code i get two errors:
1.
ArticleInterface should be declared abstract; it does not define itemStateChanged(java.awt.event.ItemEvent) in ArticleInterface

2.
//The second error i get from this code snippet. It cannot resolve symbol Date in the first line....
Date currentDate = new Date();
DateFormat fmt = getDateInstance(Locale.SHORT);                                          
String formatert = fmt.format(currentDate);

Please help.