Help Please I am new to programming Java1.3.1

Question

I am having the following problem with the appletviewer for the following code and screen print of error message. I would greatly aperciate any help i can get.Thanks Adera...
my e-mail address is [email protected]
Sorry the screen print will not copy into here so i will type it out.
java.lang.ClassCastException:Calculator
at sun.applet.AppletPanel.createApplet(AppletPanel.java:579)
at sun.applet.AppletPanel.runLoader(AppletPanel.java:515)
at sun.applet.AppletPanel.run(AppletPanel.java:293)
at java.lang.Thread.run(Thread.java:484)
Here is my code..
//Adera Currie Student Id# 31248
//Course Title: Internet Programming
//Due Date: August 13th, 2002
//calculator.Java
//Hilltop Library Calculator Java Project
//import javax.swing.*;
//import javax.swing.JOptionPane;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
//import java.awt.Container;
public class Calculator extends JFrame implements ActionListener
int chioce, i;
//integer variable to hold stringnums in
double calcone, calctwo;
//variables for mouse clicks
double numone, numtwo, total, holdnum, decimalCount;
String calctot, calctot1, calctot2, negnum, holdnumonetwo;
//declare text area
TextField text1;
//declare button array
Button calcbutton[], clear;
//string array to convert textfield values, string manipulation
String textfield;
String bpressedEvaluated;
//declare panel object
Panel bpanel,text2,Cpanel;
//declare variable arrays to hold the name and numbers of the buttons that
//will be created on the applet
String bnames[] = {"7","8","9","/","Sin","4","5","6",
"*","Cos","1","2","3","-","Tan",
"0",".","=","+","Neg"};
//arrays for holding the items to check for when the action click event is called
String holdOperatorVisual[] = {"/","*","-","=","+"};
String holdNumNames[] = {"0","1","2","3","4","5","6","7","8","9",".","Neg"};
String holdSciFiVisuals[] = {"Sin","Cos","Tan"};
//declare boolean values to keep track of numbers and operators either
//in use or what should be terminated
boolean operators,operators2;
boolean firstnum;
boolean secondnum;
boolean numberpressed,decimalPressed,negPressed;
public void init()
//create the panels to hold applet objects
bpanel = new Panel();
text2 = new Panel();
Cpanel = new Panel();
//set up the applet layout for the buttons and such
//BorderLayout layout = new BorderLayout(5,5);
setLayout(new BorderLayout(5,5));
//create a container object
//Container c = this.getContentPane();
//c.setLayout(new FlowLayout());
//this.setLayout( new FlowLayout() );
//set up the panels with layout manager
bpanel.setLayout( new GridLayout (4,5));
text2.setLayout(new GridLayout(1,1));
Cpanel.setLayout(new GridLayout(1,1));
//create my text field to hold the display for the user
text1 = new TextField(20);
//make it so the user cannot enter text from the keyboard
text1.setEditable(false);
text1.setBackground(Color.cyan);
text2.add(text1);
//add teh panel to the container
add(text2, BorderLayout.NORTH);
//instantiate button object
calcbutton = new Button[bnames.length];
     for ( int i = 0; i < bnames.length; i++ )
calcbutton[i] = new Button(bnames);
calcbutton[i].addActionListener(this);
//(new ActionListener()
     calcbutton[i].setBackground(Color.cyan);
//add the new button from teh array into the panel for buttons
bpanel.add(calcbutton[i]);
//add the button panel to the container object
add(bpanel, BorderLayout.CENTER);
//create the clear button to be displayed at the bottom of the screen
clear = new Button("Clear");
//add the action listener for this object
clear.addActionListener(this);
clear.setBackground(Color.cyan);
//add the clear button to the panel for the clear button
Cpanel.add(clear);
//add the clear button panel to the container
add(Cpanel, BorderLayout.SOUTH);
     public void actionPerformed(ActionEvent e)
     String bpressed = (e.getActionCommand());
     checkButtonPressed(bpressed);
     if(bpressedEvaluated=="notFound")
//JOptionPane.showMessageDialog(null, "Invalid button selection!",
// "System Message", JOptionPane.INFORMATION_MESSAGE);
public void checkButtonPressed(String valueIn)
          String me;
          String takeValueIn = valueIn;
          double tot=0;
          String tat;
          for (i=0;i<holdNumNames.length;i++)
     if(takeValueIn == holdNumNames[i])
     //if there is a second operator in memory, then clear the contents of the
     //text box and start over adding in new numbers from the user
     if (takeValueIn == ".")
     if (decimalPressed == true)
//JOptionPane.showMessageDialog(null, "This function cannot be used with any other operatorsdecimalPressed== " + decimalPressed,"System Message.", JOptionPane.INFORMATION_MESSAGE);
break;
else
decimalPressed = true;
if(takeValueIn == "Neg")
     if(numberpressed == false && negPressed == false)
negPressed = true;
takeValueIn = "-";
else
break;
if (operators2 == true)
     String nothing;
     nothing = "";
     text1.setText(nothing);
     operators2 = false;
//if there is no data in the text box, then set this number as the new text
     if (text1.getText().length() == 0)
text1.setText(takeValueIn);
//if there is text contained in the text field, then append this number to
//to the text field and set the new text view for the user
else if (text1.getText().length() != 0)
holdnumonetwo = text1.getText();
holdnumonetwo += takeValueIn;
text1.setText(holdnumonetwo);
numberpressed = true;
bpressedEvaluated = "Found";
break;
for (i=0;i<holdOperatorVisual.length;i++)
if(takeValueIn == holdOperatorVisual[i])
if (takeValueIn == "=")
if (operators == true)
//convert text to number two for calculation
numtwo = Double.parseDouble(text1.getText());
//do the math
if(calctot1=="-")
tot = numone-numtwo;
else if(calctot1=="+")
tot = numone+numtwo;
else if(calctot1=="/")
tot = numone/numtwo;
else if(calctot1=="*")
tot = numone*numtwo;
//convert total to string
tat = String.valueOf(tot);
//set the visual value to the screen for the user
text1.setText(tat);
//update the new number one to be used in the next calculation
numone = tot;
decimalPressed = false;
negPressed = false;
numberpressed = false;
break;
else
if (operators != true && text1.getText().length()!= 0)
calctot1 = takeValueIn;
numone = Double.parseDouble(text1.getText());
String t;
t = "";
text1.setText(t);
firstnum = true;
operators = true;                                    decimalPressed = false;
negPressed = false;                               numberpressed = false;                                    break;
else if (operators == true && text1.getText().length()!= 0)
{                                                                                                                                                     calctot2 = takeValueIn;                                                                                                                                                     numtwo = Double.parseDouble(text1.getText());                                                                                                                                                     //do the math                                                                                                                                                if(calctot1=="-")                                                                                                                                                       {                                                                                                                                                     tot = numone-numtwo;                                                                                                                                                    }                                    else if(calctot1=="+")                                    {                                                                                                                                                        tot = numone+numtwo;                                                                                                                                                        }                                    else if(calctot1=="/")                                    {                                                                                                                                                            tot = numone/numtwo;                                                                                                                                                            }                                    else if(calctot1=="*")                                    {                                                                                                                                                                tot = numone*numtwo;                                                                                                                                                               }                                    //convert total to string                                    tat = String.valueOf(tot);                                    //set the visual value to the screen for the user                                    text1.setText(tat);                               //update the new number one to be used in the next calculation                               numone = tot;                               operators2 = true;                               decimalPressed = false;                               negPressed = false;                               }                               calctot1 = calctot2;                               //set the flags                               firstnum = true;                               decimalPressed = false;                               negPressed = false;                               numberpressed = false;                               bpressedEvaluated = "found";                               break;                               }                          }                     }                          for(i=0;i<holdSciFiVisuals.length;i++)                     {                                                                                                                                                         if(takeValueIn == holdSciFiVisuals[i])                     {                                                                                                                                                        if (text1.getText().length()!= 0 && operators != true)                                                                                                                                                            {                                                                                                                                                               double s=0;                                                                                                                                                                numone = Double.parseDouble(text1.getText());                                                                                                                                                            if(takeValueIn == "Sin")                                                                                                                                                                 s = Math.sin(numone);                                                                                                                                                            if(takeValueIn == "Cos")                                                                                                                                                                  s = Math.cos(numone);                                                                                                                                                            if(takeValueIn == "Tan")                                                                                                                                                                  s = Math.tan(numone);                                                                                                                                                                  firstnum = true;                                                                                                                                                                  String ch;                                                                                                                                                                  ch = String.valueOf(s);                                                                                                                                                                  text1.setText(ch);                                                                                                                                                                  operators2 = true;                                                                                                                                                            }                     else if (operators == true)                     {                                                                                                                                                                 //JOptionPane.showMessageDialog(null, "This function cannot be used with any other operators",                                                                                                                                                          //"System Message", JOptionPane.INFORMATION_MESSAGE);                                                                                                                                                                     break;                                                                                                                                                               }                          bpressedEvaluated = "found";                          decimalPressed = false;                          negPressed = false;                          numberpressed = false;                     }                }                          bpressedEvaluated = "notFound";                     if(takeValueIn == "Clear")
//reset all the values that are either presently in use, or that will be the
//first values to be used after the text field is cleared, to start from square one
numone = 0;
numtwo = 0;
//set the flags
firstnum = false;
secondnum = false;
operators = false;
operators2 = false;
decimalPressed = false;
negPressed = false;
numberpressed = false;
//declare string to help clear the text field
String cn;
cn = "";
//set the text field to nothing, an empty string
text1.setText(cn);
     //execute application
     public static void main (String args[])
     Calculator application = new Calculator();
//     addMouseListener(this);
     application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Answer 1

//Adera Currie Student Id# 31248
//Course Title: Internet Programming
//Due Date: August 13th, 2002
//calculator.Java
//Hilltop Library Calculator Java Project
//import javax.swing.*;
//import javax.swing.JOptionPane;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
//import java.awt.Container;
public class Calculator extends JFrame implements ActionListener
     int chioce, i;
     //integer variable to hold stringnums in
     double calcone, calctwo;
     //variables for mouse clicks
     double numone, numtwo, total, holdnum, decimalCount;
     String calctot, calctot1, calctot2, negnum, holdnumonetwo;
     //declare text area
     TextField text1;
     //declare button array
     Button calcbutton[], clear;
     //string array to convert textfield values, string manipulation
     String textfield;
     String bpressedEvaluated;
     //declare panel object
     Panel bpanel,text2,Cpanel;
     //declare variable arrays to hold the name and numbers of the buttons that
     //will be created on the applet
     String bnames[] = {"7","8","9","/","Sin","4","5","6",
"*","Cos","1","2","3","-","Tan",
"0",".","=","+","Neg"};
     //arrays for holding the items to check for when the action click event is called
     String holdOperatorVisual[] = {"/","*","-","=","+"};
     String holdNumNames[] = {"0","1","2","3","4","5","6","7","8","9",".","Neg"};
     String holdSciFiVisuals[] = {"Sin","Cos","Tan"};
     //declare boolean values to keep track of numbers and operators either
     //in use or what should be terminated
     boolean operators,operators2;
     boolean firstnum;
     boolean secondnum;
     boolean numberpressed,decimalPressed,negPressed;
     public Calculator()
          //create the panels to hold applet objects
          bpanel = new Panel();
          text2 = new Panel();
          Cpanel = new Panel();
          //set up the applet layout for the buttons and such
          //BorderLayout layout = new BorderLayout(5,5);
          getContentPane().setLayout(new BorderLayout(5,5));
          //create a container object
          //Container c = this.getContentPane();
          //c.setLayout(new FlowLayout());
          //this.setLayout( new FlowLayout() );
          //set up the panels with layout manager
          bpanel.setLayout( new GridLayout (4,5));
          text2.setLayout(new GridLayout(1,1));
          Cpanel.setLayout(new GridLayout(1,1));
          //create my text field to hold the display for the user
          text1 = new TextField(20);
          //make it so the user cannot enter text from the keyboard
          text1.setEditable(false);
          text1.setBackground(Color.cyan);
          text2.add(text1);
          //add teh panel to the container
          getContentPane().add(text2, BorderLayout.NORTH);
          //instantiate button object
          calcbutton = new Button[bnames.length];
          for ( int i = 0; i < bnames.length; i++ )
               calcbutton[0] = new Button(bnames[0]);
               calcbutton[0].addActionListener(this);
               //(new ActionListener()
               calcbutton[0].setBackground(Color.cyan);
               //add the new button from teh array into the panel for buttons
               bpanel.add(calcbutton[0]);
          //add the button panel to the container object
          getContentPane().add(bpanel, BorderLayout.CENTER);
          //create the clear button to be displayed at the bottom of the screen
          clear = new Button("Clear");
          //add the action listener for this object
          clear.addActionListener(this);
          clear.setBackground(Color.cyan);
          //add the clear button to the panel for the clear button
          Cpanel.add(clear);
          //add the clear button panel to the container
          getContentPane().add(Cpanel, BorderLayout.SOUTH);
          pack();
          show();
     public void actionPerformed(ActionEvent e)
          String bpressed = (e.getActionCommand());
          checkButtonPressed(bpressed);
          if(bpressedEvaluated=="notFound")
               //JOptionPane.showMessageDialog(null, "Invalid button selection!",
               // "System Message", JOptionPane.INFORMATION_MESSAGE);
     public void checkButtonPressed(String valueIn)
          String me;
          String takeValueIn = valueIn;
          double tot=0;
          String tat;
          for (i=0;i<holdNumNames.length;i++)
               if(holdNumNames.equals(takeValueIn + ""))
                    //if there is a second operator in memory, then clear the contents of the
                    //text box and start over adding in new numbers from the user
                    if(takeValueIn == ".")
                         if (decimalPressed == true)
                              //JOptionPane.showMessageDialog(null, "This function cannot be used with any other operatorsdecimalPressed== " + decimalPressed,"System Message.", JOptionPane.INFORMATION_MESSAGE);
                              break;
                         else
                              decimalPressed = true;
                    if(takeValueIn == "Neg")
                         if(numberpressed == false && negPressed == false)
                              negPressed = true;
                              takeValueIn = "-";
                         else
                              break;
                    if (operators2 == true)
                         String nothing;
                         nothing = "";
                         text1.setText(nothing);
                         operators2 = false;
                    //if there is no data in the text box, then set this number as the new text
                    if(text1.getText().length() == 0)
                         text1.setText(takeValueIn);
                    //if there is text contained in the text field, then append this number to
                    //to the text field and set the new text view for the user
                    else if (text1.getText().length() != 0)
                         holdnumonetwo = text1.getText();
                         holdnumonetwo += takeValueIn;
                         text1.setText(holdnumonetwo);
                    numberpressed = true;
                    bpressedEvaluated = "Found";
                    break;
          for (i=0;i<holdOperatorVisual.length;i++)
               if(holdOperatorVisual.equals(takeValueIn+""))
                    if (takeValueIn == "=")
                         if (operators == true)
                              //convert text to number two for calculation
                              numtwo = Double.parseDouble(text1.getText());
                              //do the math
                              if(calctot1=="-")
                                   tot = numone-numtwo;
                              else if(calctot1=="+")
                                   tot = numone+numtwo;
                              else if(calctot1=="/")
                                   tot = numone/numtwo;
                              else if(calctot1=="*")
                                   tot = numone*numtwo;
                              //convert total to string
                              tat = String.valueOf(tot);
                              //set the visual value to the screen for the user
                              text1.setText(tat);
                              //update the new number one to be used in the next calculation
                              numone = tot;
                              decimalPressed = false;
                              negPressed = false;
                              numberpressed = false;
                         break;
                    else
                         if (operators != true && text1.getText().length()!= 0)
                              calctot1 = takeValueIn;
                              numone = Double.parseDouble(text1.getText());
                              String t;
                              t = "";
                              text1.setText(t);
                              firstnum = true;
                              operators = true; decimalPressed = false;
                              negPressed = false; numberpressed = false; break;
                         else if (operators == true && text1.getText().length()!= 0)
                         { calctot2 = takeValueIn; numtwo = Double.parseDouble(text1.getText()); //do the math if(calctot1=="-") { tot = numone-numtwo; } else if(calctot1=="+") { tot = numone+numtwo; } else if(calctot1=="/") { tot = numone/numtwo; } else if(calctot1=="*") { tot = numone*numtwo; } //convert total to string tat = String.valueOf(tot); //set the visual value to the screen for the user text1.setText(tat); //update the new number one to be used in the next calculation numone = tot; operators2 = true; decimalPressed = false; negPressed = false; } calctot1 = calctot2; //set the flags firstnum = true; decimalPressed = false; negPressed = false; numberpressed = false; bpressedEvaluated = "found"; break; } } } for(i=0;i<holdSciFiVisuals.length;i++) { if(takeValueIn == holdSciFiVisuals) { if (text1.getText().length()!= 0 && operators != true) { double s=0; numone = Double.parseDouble(text1.getText()); if(takeValueIn == "Sin") s = Math.sin(numone); if(takeValueIn == "Cos") s = Math.cos(numone); if(takeValueIn == "Tan") s = Math.tan(numone); firstnum = true; String ch; ch = String.valueOf(s); text1.setText(ch); operators2 = true; } else if (operators == true) { //JOptionPane.showMessageDialog(null, "This function cannot be used with any other operators", //"System Message", JOptionPane.INFORMATION_MESSAGE); break; } bpressedEvaluated = "found"; decimalPressed = false; negPressed = false; numberpressed = false; } } bpressedEvaluated = "notFound"; if(takeValueIn == "Clear")
                                   //reset all the values that are either presently in use, or that will be the
                                   //first values to be used after the text field is cleared, to start from square one
                                   numone = 0;
                                   numtwo = 0;
                                   //set the flags
                                   firstnum = false;
                                   secondnum = false;
                                   operators = false;
                                   operators2 = false;
                                   decimalPressed = false;
                                   negPressed = false;
                                   numberpressed = false;
                                   //declare string to help clear the text field
                                   String cn;
                                   cn = "";
                                   //set the text field to nothing, an empty string
                                   text1.setText(cn);
     //execute application
     public static void main (String args[])
          Calculator application = new Calculator();
          // addMouseListener(this);
          application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}