what is StackOverflowError(code)

[henry akoma]

 
/**code by Akoma Henry
* Calculator
*compile as Cal.java
*/
 
import java.awt.*;
import java.awt.event.*;
import java.awt.Frame.*;
import javax.swing.*;
import javax.swing.text.*;
 
class Cal extends JFrame{
Button button=new Button();
static JTextField tf=new JTextField(20);
 
private void build(){
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("Calculator");
tf.setHorizontalAlignment(JTextField.RIGHT);
buildGUI();
pack();
setVisible(true);
}
 
private void buildGUI(){
Container cp=getContentPane();
cp.add(BorderLayout.NORTH,tf);
cp.add(BorderLayout.EAST,button.panel3());
cp.add(BorderLayout.SOUTH,button.panel12());
}
 
public Insets insets(){
return new Insets(35,10,10,10);
}
 
 
public static void main(String[]s){
new Cal().build();
}
}
 
 
class Button {

JButtonListener1 jbl1=new JButtonListener1();
JButtonListener2 jbl2=new JButtonListener2();
JButton 
NA=new JButton("0"),
NB=new JButton("1"),
NC=new JButton("2"),
ND=new JButton("3"),
NE=new JButton("4"),
NF=new JButton("5"),
NG=new JButton("6"),
NH=new JButton("7"),
NI=new JButton("8"),
NJ=new JButton("9"),



bA=new JButton("+"),
bB=new JButton("-"),
bC=new JButton("*"),
bD=new JButton("/"),
bE=new JButton("%"),
bF=new JButton("+/-"),
bG=new JButton("1/x"),
bH=new JButton("sqrt"),
bI=new JButton("."),
bJ=new JButton("="),


bK=new JButton("DEL"),
bL=new JButton("    C   ");


JPanel panel3(){
JButton[]jb3=new JButton[]{bK,bL};
JPanel 
panel3=new JPanel();

panel3.setLayout(new GridLayout(1,2));
for(int i=0;i<jb3.length;i++){
jb3[i].setBackground(Color.red);
jb3[i].addActionListener(jbl1);
panel3.add(jb3[i]);}
 
return panel3;
}
 
JPanel panel12(){

JButton[]jb12=new JButton[]{NA,NB,NC,ND,NE,NF,NG,NH,NI,NJ,bA,bB,bC,bD,bE,bF,bG,bH,bI,bJ};
for(int i=0;i<jb12.length;i++){
jb12[i].setBackground(Color.blue);
jb12[i].setForeground(Color.white);}

 
Box bh=Box.createHorizontalBox();
JPanel 
panel =new JPanel(),
panel1=new JPanel(),
panel2=new JPanel();

for(int i=0;i<10;i++)
jb12[i].addActionListener(jbl2);
jb12[18].addActionListener(jbl2);
 
for(int i=10;i<18;i++)
jb12[i].addActionListener(jbl1);
jb12[19].addActionListener(jbl1);

panel1.setLayout(new GridLayout(5,2));
for(int i=0;i<10;i++)
panel1.add(jb12[i]);


panel2.setLayout(new GridLayout(5,2));
for(int i=10;i<20;i++)
panel2.add(jb12[i]);


bh.add(panel1);
bh.add(Box.createHorizontalStrut(5));
bh.add(panel2);

panel.setLayout(new GridLayout(1,1));
panel.add(bh);
return panel;
}

}
 
 
 
 

/****MATH OPERATION REQUESTED HERE****/
 
class JButtonListener1 implements ActionListener { 

Cal cal=new Cal();
static String data1,data2;
Computation compute=new Computation();
JButtonListener2 jbl2=new JButtonListener2();

public void actionPerformed(ActionEvent e){
String sign=((JButton)e.getSource()).getText();
 
if(sign=="+"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
data1=data1.concat("+");
jbl2.emptyBuffer();
}catch(BadLocationException ble){}
}
 
if(sign=="-"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
data1=data1.concat("-");
jbl2.emptyBuffer();
}catch(BadLocationException ble){}
}
 
if(sign=="*"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
data1=data1.concat("*");
jbl2.emptyBuffer();
}catch(BadLocationException ble){}
}
 
if(sign=="/"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
data1=data1.concat("/");
jbl2.emptyBuffer();
}catch(BadLocationException ble){}
}
 
if(sign=="%"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
data1=data1.concat("%");
jbl2.emptyBuffer();
}catch(BadLocationException ble){}
}

if(sign=="+/-")
compute.plusMinus();
 
if(sign=="="){
try{
data2=cal.tf.getText(0,jbl2.buffer.length());
}catch(BadLocationException ble){}
 
if(data1.charAt(data1.length()-1)=='+')
compute.summation(data1,data2);

if(data1.charAt(data1.length()-1)=='-')
compute.difference(data1,data2);

if(data1.charAt(data1.length()-1)=='*')
compute.multiplication(data1,data2);
 
if(data1.charAt(data1.length()-1)=='/')
compute.division(data1,data2);
 
if(data1.charAt(data1.length()-1)=='%')
compute.modulo(data1,data2);
}
 
if(sign=="C"){
jbl2.emptyBuffer();}


if(sign=="DEL")jbl2.del();
 
if(sign=="1/x"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
compute.inverse(data1);
}catch(BadLocationException ble){}
}

if(sign=="sqrt"){
try{
data1=cal.tf.getText(0,jbl2.buffer.length());
compute.squareRoot(data1);
}catch(BadLocationException ble){}
}


}
}
 
 
class JButtonListener2 implements ActionListener{
 
Cal cal=new Cal();
String remString;
static StringBuffer buffer=new StringBuffer(64);
 
public  void actionPerformed(ActionEvent e){
String value=((JButton)e.getSource()).getText();
JTextFieldDisplay(value);
if(value==".")dot();
}
 
void JTextFieldDisplay(String str){
String name=buffer.append(str).toString();
cal.tf.setText(name);
}

 void emptyBuffer(){
cal.tf.setText("");
buffer.delete(0,buffer.length());
}
 
 void del(){
try{
remString=cal.tf.getText(0,buffer.length()-1);
}catch(BadLocationException ble){}
emptyBuffer();
JTextFieldDisplay(remString);
}
 
void dot(){
String addDot=null;
try{
addDot=cal.tf.getText(0,buffer.length());

if(addDot.charAt(0)=='.'){
emptyBuffer();
JTextFieldDisplay("0.");}
else{
int nextDotIndex=addDot.length()-1;
char nextDot=addDot.charAt(nextDotIndex);
for(int i=0;i<nextDotIndex;i++)
if(addDot.charAt(i)==nextDot)
addDot=cal.tf.getText(0,buffer.length()-1);
emptyBuffer();
JTextFieldDisplay(addDot);}
}catch(BadLocationException ble){}
}

}
 
 
/****MATHS COMPUTATION PERFORMED HERE*****/
 
class Computation{
 
Cal cal=new Cal();
JButtonListener2 jbl2=new JButtonListener2();
 
void plusMinus(){
try{
String 
plusMinus1=cal.tf.getText(0,jbl2.buffer.length()),
plusMinus2=cal.tf.getText(0,jbl2.buffer.length());
if(plusMinus1=="")cal.tf.setText("");
if(plusMinus2.charAt(0)=='-'){
jbl2.emptyBuffer();
plusMinus2=plusMinus2.substring(1,plusMinus2.length());
jbl2.JTextFieldDisplay(plusMinus2);}
if(plusMinus1.charAt(0)!='-'){
jbl2.emptyBuffer();
plusMinus1="-".concat(plusMinus1);
jbl2.JTextFieldDisplay(plusMinus1);}
}catch(BadLocationException ble){}
}
 
void summation(String nextData1,String nextData2){
double 
value1=Double.parseDouble(nextData1.substring(0,nextData1.length()-1)),
value2=Double.parseDouble(nextData2),
sum=value1+value2;
String sumText=Double.toString(sum);
if((sumText.charAt(sumText.length()-2)=='.')&(sumText.charAt(sumText.length()-1)=='0'))
sumText=sumText.substring(0,sumText.length()-2);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(sumText);
}
 
void difference(String nextData1,String nextData2){
double 
value1=Double.parseDouble(nextData1.substring(0,nextData1.length()-1)),
value2=Double.parseDouble(nextData2),
difference=value1-value2;
String differenceText=Double.toString(difference);
if((differenceText.charAt(differenceText.length()-2)=='.')
&(differenceText.charAt(differenceText.length()-1)=='0'))
differenceText=differenceText.substring(0,differenceText.length()-2);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(differenceText);
}
 
void multiplication(String nextData1,String nextData2){
double 
value1=Double.parseDouble(nextData1.substring(0,nextData1.length()-1)),
value2=Double.parseDouble(nextData2),
product=value1*value2;
String productText=Double.toString(product);
if((productText.charAt(productText.length()-2)=='.')&(productText.charAt(productText.length()-1)=='0'))
productText=productText.substring(0,productText.length()-2);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(productText);
}
 
void division(String nextData1,String nextData2){
double 
value1=Double.parseDouble(nextData1.substring(0,nextData1.length()-1)),
value2=Double.parseDouble(nextData2),
quotient=value1/value2;
String quotientText=Double.toString(quotient);
if((quotientText.charAt(quotientText.length()-2)=='.')&(quotientText.charAt(quotientText.length()-1)=='0'))
quotientText=quotientText.substring(0,quotientText.length()-2);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(quotientText);
}

void modulo(String nextData1,String nextData2){
double 
value1=Double.parseDouble(nextData1.substring(0,nextData1.length()-1)),
value2=Double.parseDouble(nextData2),
modul=value1%value2;
int modulo=(int)modul;
String moduloText=Integer.toString(modulo);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(moduloText);
}
 
void inverse(String nextData){
double 
value=Double.parseDouble(nextData),
inverse=1/value;
String inverseText=Double.toString(inverse);
if((inverseText.charAt(inverseText.length()-2)=='.')&(inverseText.charAt(inverseText.length()-1)=='0'))
inverseText=inverseText.substring(0,inverseText.length()-2);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(inverseText);
}
 
void squareRoot(String nextData){
double 
value=Double.parseDouble(nextData),
squareRoot=Math.sqrt(value);
String squareRootText=Double.toString(squareRoot);
if((squareRootText.charAt(squareRootText.length()-2)=='.')&(squareRootText.charAt(squareRootText.length()-1)=='0'))
squareRootText=squareRootText.substring(0,squareRootText.length()-2);
jbl2.emptyBuffer();
jbl2.JTextFieldDisplay(squareRootText);
}
 
 
}
 
 

[ July 25, 2005: Message edited by: henry akoma ]

[Jaikiran Pai]

Pretty large code, Can you post the detail log message, so that we can narrow down on the error

[henry akoma]

JAIKIRAN,
i am sorry, i dont know what u mean by the log message.
but if paradventure u mean the console display, it reads: Exception in thread "main" java.lang.StackOverflowError.

if this is not what u requested, please direct me how to get it.
thank u

[Jaikiran Pai]

Hi Henry,
What i can make out from the error message is that your program is recursively invoking some method(infinite loop scenario) and control is NOT coming out of some funcation. Will have go through the entire code once to find out which method is being invoked recursively.

One option to find out the problem is to place a
System.out.println("Entering theNameOfTheMethod");
at the start of each method. This will help you track the flow

[Jaikiran Pai]

Also, in the code there are some looping statements. Even these might be cause of the exception. Reason might be the condition for breaking out of the loop is NEVER met. Check it out

[Ernest Friedman-Hill]

Originally posted by jaikiran pai:
Even these might be cause of the exception. Reason might be the condition for breaking out of the loop is NEVER met.

This would cause the program to loop forever, but it would not cause a StackOverflowException.

[Jaikiran Pai]

Ya you are right. Accept my mistake. Just wanted, Henry to confirm that if there are any method invocations in the looping statement, then that method
might have been called continuously because of the condition for breaking the loop never being met

Thanks for pointing the mistake