ClassCastException in BasicUISlider

Question

I'm trying to set up a JSlider's labels to go from 1->F instead of 1->16.
The JSlider API says it requires a type Dictionary for void setLabelTable(Dictionary Label)
So I created a class for that and everytime I run the program I get this error:
java.lang.ClassCastException
     at javax.swing.plaf.basic.BasicSliderUI.getHighestValueLabel(BasicSliderUI.java:729)
     at javax.swing.plaf.basic.BasicSliderUI.calculateTrackBuffer(BasicSliderUI.java:423)
     at javax.swing.plaf.basic.BasicSliderUI.calculateGeometry(BasicSliderUI.java:352)
     at javax.swing.plaf.basic.BasicSliderUI$PropertyChangeHandler.propertyChange(BasicSliderUI.java:584)
     at javax.swing.plaf.metal.MetalSliderUI$MetalPropertyListener.propertyChange(MetalSliderUI.java:95)
     at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:264)
     at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:232)
     at javax.swing.JComponent.firePropertyChange(JComponent.java:3819)
     at javax.swing.JSlider.setLabelTable(JSlider.java:630)
     at JApplet1.createBaseOther(JApplet1.java:265)
     at JApplet1.init(JApplet1.java:57)
     at sun.applet.AppletPanel.run(AppletPanel.java:353)
     at java.lang.Thread.run(Thread.java:534)
Line 729 is:
label = (Component)dictionary.get( new Integer( highestValue ) );And the entire method is:
protected Component getHighestValueLabel() {
        Dictionary dictionary = slider.getLabelTable();
        Component label = null;
        if ( dictionary != null ) {
            Enumeration keys = dictionary.keys();
            if ( keys.hasMoreElements() )
                int highestValue = ((Integer)keys.nextElement()).intValue();
                    System.out.println("" +highestValue);
                while ( keys.hasMoreElements() )
                    int value = ((Integer)keys.nextElement()).intValue();
                    highestValue = Math.max( value, highestValue );
                    System.out.println("HV " +highestValue);
                    System.out.println("size " +dictionary.size());
                label = (Component)dictionary.get( new Integer( highestValue ) );
        return label;
    }My Dictionary class is below
* The Dictionary class is the abstract parent of any class,
* such as Hashtable, which maps keys to values. Every key
* and every value is an object. In any one Dictionary object,
* every key is associated with at most one value. Given a
* Dictionary and a key, the associated element can be looked
* up. Any non-null object can be used as a key and as a value.
import java.util.*;
class SliderLabels extends Dictionary
     Hashtable numbers = new Hashtable();
     //Sole constructor. (For invocation by subclass constructors, typically implicit.)
     public SliderLabels()
          numbers.put(new Integer(0), new String("null");
          numbers.put(new Integer(1), new String("0"));
         numbers.put(new Integer(2), new String("1"));
          numbers.put(new Integer(3), new String("2"));
          numbers.put(new Integer(4), new String("3"));
          numbers.put(new Integer(5), new String("4"));
          numbers.put(new Integer(6), new String("5"));
          numbers.put(new Integer(7), new String("6"));
          numbers.put(new Integer(8), new String("7"));
          numbers.put(new Integer(9), new String("8"));
          numbers.put(new Integer(10), new String("9"));
          numbers.put(new Integer(11), new String("A"));
          numbers.put(new Integer(12), new String("B"));
          numbers.put(new Integer(13), new String("C"));
          numbers.put(new Integer(14), new String("D"));
          numbers.put(new Integer(15), new String("E"));
          numbers.put(new Integer(16), new String("F"));//key     ,    value
     //Returns an enumeration of the values in this dictionary.
     public Enumeration elements()
          return numbers.elements();
     //Returns the value to which the key is mapped in this dictionary.
     public Object get(Object key)
          return numbers.get(key);
     //Tests if this dictionary maps no keys to value.
     public boolean isEmpty()
          if (numbers.isEmpty())
               return true;
          return false;
     //Returns an enumeration of the keys in this dictionary.
     public Enumeration keys()
          return numbers.keys();
     //Maps the specified key to the specified value in this dictionary.
     public Object put(Object key, Object value)
          return numbers.put(key, value);
     //Removes the key (and its corresponding value) from this dictionary.
     public Object remove(Object key)
          return numbers.remove(key);
     //Returns the number of entries (dinstint keys) in this dictionary.
     public int size()
          return numbers.size();
}So what am i doing wrong here?
thanks

Answer 1

I'm not familiar with JSliders, but the getHighestValueLabel() expects the Dictionary to contain Components. Your Dictionary contains Strings. I would try something like changing the Strings to JLabels.