title: Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
body: <p>Hey guys I get the errors</p>
  
  <pre><code>Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
          at P6.itemStateChanged(P6.java:215)
          at javax.swing.AbstractButton.fireItemStateChanged(AbstractButton.java:2
  023)
          at javax.swing.AbstractButton$Handler.itemStateChanged(AbstractButton.ja
  va:2325)
          at javax.swing.DefaultButtonModel.fireItemStateChanged(DefaultButtonMode
  l.java:440)
          at javax.swing.JToggleButton$ToggleButtonModel.setSelected(JToggleButton
  .java:255)
          at javax.swing.ButtonGroup.setSelected(ButtonGroup.java:147)
          at javax.swing.JToggleButton$ToggleButtonModel.setSelected(JToggleButton
  .java:237)
          at javax.swing.JToggleButton$ToggleButtonModel.setPressed(JToggleButton.
  java:272)
          at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonL
  istener.java:236)
          at java.awt.Component.processMouseEvent(Component.java:6267)
          at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
          at java.awt.Component.processEvent(Component.java:6032)
          at java.awt.Container.processEvent(Container.java:2041)
          at java.awt.Component.dispatchEventImpl(Component.java:4630)
          at java.awt.Container.dispatchEventImpl(Container.java:2099)
          at java.awt.Component.dispatchEvent(Component.java:4460)
          at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577
  )
          at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
  
          at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
          at java.awt.Container.dispatchEventImpl(Container.java:2085)
          at java.awt.Component.dispatchEvent(Component.java:4460)
          at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
          at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThre
  ad.java:269)
          at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.
  java:184)
          at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
  ad.java:174)
          at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
  
          at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
  
          at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
  </code></pre>
  
  <p>In</p>
  
  <pre><code>import java.awt.Color;
  import java.awt.Container;
  import java.awt.FlowLayout;
  import java.awt.Font;
  import java.awt.Graphics;
  import java.awt.event.ItemEvent;
  import java.awt.event.ItemListener;
  import java.awt.event.MouseEvent;
  import java.awt.event.MouseListener;
  import java.awt.event.MouseMotionListener;
  import javax.swing.ButtonGroup;
  import javax.swing.JApplet;
  import javax.swing.JComboBox;
  import javax.swing.JRadioButton;
  
  public class P6 extends JApplet implements MouseListener, MouseMotionListener, ItemListener
  {
     private final int RED = 1;
     private final int ORANGE = 2;
     private final int YELLOW = 3;
     private final int GREEN = 4;
     private final int BLUE = 5;
     private final int CYAN = 6;
     private final int PINK = 7;
     private final int MAGENTA =8;
     private final int BLACK = 9;
     private final int ARC = 1;
     private final int LINE = 2;
     private final int OVAL = 3;
     private final int RECT = 4;
     private final int POLY = 5;
  
     private String[] colorNames = { "Red", "Orange", "Yellow", "Green", "Blue",
     "Cyan", "Pink", "Magenta", "Black"};
     private JComboBox colorComboBox;
     private JRadioButton jrbArc;
     private JRadioButton jrbLine;
     private JRadioButton jrbOval;
     private JRadioButton jrbRect;
     private JRadioButton jrbPolygon;
     private int color = 0;
     private int shape = 0;
     private int x1;
     private int y1;
     private int x2;
     private int y2;
  
     public void init()
     {
        Container c = getContentPane();
        c.setLayout( new FlowLayout() );
        c.setBackground( Color.orange );
        JComboBox colorComboBox = new JComboBox(colorNames);
        colorComboBox.addItemListener(this);
  
        JRadioButton jrbArc = new JRadioButton("Arc");
        jrbArc.addItemListener(this);
        JRadioButton jrbLine = new JRadioButton("Line");
        jrbLine.addItemListener(this);
        JRadioButton jrbOval = new JRadioButton("Oval");
        jrbOval.addItemListener(this);
        JRadioButton jrbRect = new JRadioButton("Rectangle");
        jrbRect.addItemListener(this);
            JRadioButton jrbPolygon = new JRadioButton("Polygon");
        jrbPolygon.addItemListener(this);
  
        ButtonGroup btg = new ButtonGroup();
        btg.add(jrbArc);
        c.add(jrbArc);
        btg.add(jrbLine);
        c.add(jrbLine);
        btg.add(jrbOval);
        c.add(jrbOval);
        btg.add(jrbRect);
        c.add(jrbRect);
        btg.add(jrbPolygon);
        c.add(jrbPolygon);
        c.add(colorComboBox);
  
        addMouseMotionListener(this);
        addMouseListener(this);
  
     }
  
     public void paint(Graphics g)
     {
        super.paint(g);
        g.setColor(Color.white);
        g.fillRect(20, 50, 500, 500);
        g.setFont( new Font("Serif", Font.ITALIC+Font.BOLD, 18));
        g.setColor(Color.black);
        g.drawString("Start Here!", 10, 50);
        g.drawString("End Here!", 510, 560);
  
        switch (this.color)
        {
           case 1:
             g.setColor(Color.red);
             break;
           case 2:
             g.setColor(Color.orange);
             break;
           case 3:
             g.setColor(Color.yellow);
             break;
           case 4:
             g.setColor(Color.green);
             break;
           case 5:
             g.setColor(Color.blue);
             break;
           case 6:
             g.setColor(Color.cyan);
             break;           
           case 7:
             g.setColor(Color.pink);
             break;
           case 8:
             g.setColor(Color.magenta);
             break;
           case 9:
             g.setColor(Color.black);
             break;
        }
  
        switch (shape)
            {
          case 1:
            g.fillArc(this.x1, this.y1, this.x2 - this.x1, this.y2 - this.y1, 0, 90);
            g.fillArc(this.x1, this.y1, this.x2 - this.x1, this.y2 - this.y1, 180,90);
            break;
          case 2:
            g.drawLine(this.x1, this.y1, this.x2, this.y2);
            break;
          case 3:
            g.fillOval(this.x1, this.y1, this.x2 - this.x1, this.y2 - this.y1);
            break;
          case 4:
            g.fillRect(this.x1, this.y1, this.x2 - this.x1, this.y2 - this.y1);
            break;
          case 5:
            int[] arr1 = { this.x1, this.x2, this.x1, this.x2, this.x1};
            int[] arr2 = { this.y1, this.y1, this.y2 ,this.y2, this.y1};
            g.fillPolygon(arr1, arr2, 5);
            break;
        }
     }
  
     public void mousePressed( MouseEvent e)
     {
        this.x1 = e.getX();
        this.y1 = e.getY();
     }
  
     public void mouseDragged( MouseEvent e)
     {
        this.x2 = e.getX();
        this.y2 = e.getY();
     }
  
     public void mouseReleased( MouseEvent e)
     {
        this.x2 = e.getX();
        this.y2 = e.getY();
     }
  
    public void mouseClicked( MouseEvent e)
    {
    }
  
    public void mouseEntered( MouseEvent e)
    {
    }
  
    public void mouseExited( MouseEvent e)
    {
    }
  
    public void mouseMoved( MouseEvent e)
    {
      showStatus( " (" + e.getX() + ", " + e.getY() +")");
    }
  
    public void itemStateChanged(ItemEvent i)
    {
       if(this.jrbArc.isSelected())
         this.shape = ARC;
       else if( this.jrbLine.isSelected())
         this.shape = LINE;
       else if( this.jrbOval.isSelected())
         this.shape = OVAL;
       else if( this.jrbRect.isSelected())
         this.shape = RECT;
       else if( this.jrbPolygon.isSelected())
         this.shape = POLY;
  
       this.color = ( this.colorComboBox.getSelectedIndex() + 1 );
       repaint();
     }
  }
  </code></pre>
  
  <p>I've been trying to figure this out, but no luck.
  Any help please?</p>
  
  <p>Line 215 is:</p>
  
  <pre><code>if(this.jrbArc.isSelected())
  </code></pre>