//java exception test
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import javax.swing.*;

public class DividByZeroTest extends JFrame
                  implements ActionListener{
    private JTextField inputField1,inputField2,outputField;
    private int number1,number2;
    private double result;
   
    public DivideByZeroTest(){
        super( "Excetion Test Program" );
        Container container = getContentPane();
        container.setLayout( new GridLayout(3,2));
       
        container.add(new JLabel("Enter numerator ",
                SwingConstants.RIGHT));
        inputField1 = new JTextField();
        container.add( inputField1);
       
        container.add(new JLabel("Enter denominate and Press Enter ",
                SwingConstants.RIGHT));
        inputField2 = new JTextField();
        container.add( inputField2);
        inputField2.addActionListener(this);
       
        container.add(new JLabel("Result",SwingConstants.RIGHT ));
        outputField = new JTextField();
        container.add(outputField);
       
        setSize(450,200);
        setVisible(true);
       
    }//end DivideByZeroTest method
    public void actionPerformed (ActionEvent event){
        DecimalFormat precision3 = new DecimalFormat("0.000");
        outputField.setText("");
        try {
            number1 = Integer.parseInt(inputField1.getText() );
            number2 = Integer.parseInt(inputField2.getText() );
            result = quotient(number1,number2);
            outputField.setText(precision3.format(result));
        }//end try block
        catch(NumberFormatException numberFormatException){
            JOptionPane.showMessageDialog( this,"You Must enter 2 integer",
                    "invalid Number Format",
                    JOptionPane.ERROR_MESSAGE);
        }//end catch block1
       
        catch(ArithmeticException arithmeticException){   
            JOptionPane.showMessageDialog(this,arithmeticException.toString(),
                    "Arcthmetic Exception",JOptionPane.ERROR_MESSAGE);
           
        }//end catch block2
    }//end actionperformed method
public double quotient (int numerator, int denominator)
      throws DivideByZeroException{
            if (denominator == 0)
                throw new DivideByZeroException();
            return (double)numerator / denominator;
}//end quotient method
public static void main (String args[]){
    DivideByZeroTest application = new DivideByZeroTest();
    application.setDefaultCloseOpration(
            JFrame.EXIT_ON_CLOSE);
}//end mian method
}//end class DivideByZeroTest


[ 此贴被chenpeng在2007-08-31 13:11重新编辑 ]

public class DividByZeroTest extends JFrame

  public DivideByZeroTest(){
        super( "Excetion Test Program" );

你仔细比较一下这两行

然后还有类似的拼写错误
最后你的DivideByZeroException类没有声明或者导入