Exception Handling in a project
Tue Jun 02, 2009 5:52 am
hi good morning everybody
I am doing a java project,I want to handle all the exception in a single
class,wherever the exception raises ,I want to handle it in a class
can anyone send some sample for this ,
I am doing a java project,I want to handle all the exception in a single
class,wherever the exception raises ,I want to handle it in a class
can anyone send some sample for this ,
Re: Exception Handling in a project
Fri Jun 19, 2009 3:49 am
Even it's just one class, you still need to use interface for that. Each interface will have its own listener class which will override all the methods. This is one sample code that you could try to analyze. Hope it's helpful 
- Code:
//problem statement 5.P.1
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//import java.awt.Container;
public class MyDealer extends JApplet implements KeyListener
{
//variable for the panel
JPanel panelObject;
//variables for labels
JLabel labelCustName;
JLabel labelCustCellNo;
JLabel labelCustAddress;
JLabel labelCustAge;
//variables for data entry controls
JTextField textCustName;
JTextField textCustCellNo;
JTextField textAddress;
JTextField textCustAge;
String name, no, add, age;
JButton btnSubmit;
//variables for the layout
GridBagLayout gbObject;
GridBagConstraints gbc;
public void init()
{
//initializes the layout variables
gbObject = new GridBagLayout();
gbc = new GridBagConstraints();
panelObject = (JPanel)getContentPane();
panelObject.setLayout(gbObject);
setSize(800,200);
//initializes label controls
labelCustName = new JLabel("Dealer Name");
labelCustCellNo = new JLabel("Cell Number ");
labelCustAddress= new JLabel("Address");
labelCustAge = new JLabel("Age");
//initializes data entry controls
textCustName = new JTextField(30);
textCustCellNo = new JTextField(15);
textCustAge = new JTextField(2);
textAddress = new JTextField(45);
btnSubmit = new JButton("SUBMIT");
//Add listeners to the controls
textCustName.addKeyListener(this);
textCustCellNo.addKeyListener(this);
textAddress.addKeyListener(this);
textCustAge.addKeyListener(this);
//add controls for customer name;
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx = 1;
gbc.gridy = 5;
gbObject.setConstraints(labelCustName,gbc);
panelObject.add(labelCustName);
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx = 4;
gbc.gridy = 5;
gbObject.setConstraints(textCustName,gbc);
panelObject.add(textCustName);
//add controls for cell number
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx =1;
gbc.gridy =8;
gbObject.setConstraints(labelCustCellNo,gbc);
panelObject.add(labelCustCellNo);
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx =4;
gbc.gridy =8;
gbObject.setConstraints(textCustCellNo, gbc);
panelObject.add(textCustCellNo);
//add controls for package
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx =1;
gbc.gridy =11;
gbObject.setConstraints(labelCustAddress, gbc);
panelObject.add(labelCustAddress);
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx =4;
gbc.gridy =11;
gbObject.setConstraints(textAddress, gbc);
panelObject.add(textAddress);
//add controls for customer age
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx =1;
gbc.gridy =14;
gbObject.setConstraints(labelCustAge, gbc);
panelObject.add(labelCustAge);
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.gridx =4;
gbc.gridy =14;
gbObject.setConstraints(textCustAge, gbc);
panelObject.add(textCustAge);
gbc.anchor = GridBagConstraints.SOUTH;
gbc.gridx = 4;
gbc.gridy = 16;
gbObject.setConstraints(btnSubmit,gbc);
panelObject.add(btnSubmit);
}
// BEGINNING OF KEY LISTENER FUNCTIONS
public void keyPressed(KeyEvent e)
{
Object obj = e.getSource();
if (obj == textCustName)
{
int key = e.getKeyCode();
if (key == KeyEvent.VK_ENTER)
{
String name = textCustName.getText();
if (name.length() == 0)
{
JOptionPane.showMessageDialog(this,"Name cannot be empty");
//showStatus("cannot be empty");
//return;
}
else
{
textCustCellNo.requestFocusInWindow();
}
}
}
if (obj == textCustCellNo)
{
int key = e.getKeyCode();
if (key == KeyEvent.VK_ENTER)
{
String no = textCustCellNo.getText();
if (no.length() != 10)
{
JOptionPane.showMessageDialog(this,"Mobile number entered should be of ten digits");
}
else
{
textAddress.requestFocusInWindow();
}
}
}
if (obj == textAddress)
{
int key = e.getKeyCode();
if (key == KeyEvent.VK_ENTER)
{
textCustAge.requestFocusInWindow();
}
}
if (obj == textCustAge)
{
int key = e.getKeyCode();
if (key == KeyEvent.VK_ENTER)
{
int age = Integer.parseInt(textCustAge.getText());
if (age <= 18 || age >= 100)
{
JOptionPane.showMessageDialog(this,"Wrong Age Input. Please Recheck!");
}
else
{
btnSubmit.requestFocusInWindow();
}
}
}
}
public void keyReleased(KeyEvent e)
{
}
public void keyTyped(KeyEvent e)
{
//showStatus(" Recently typed characters are : " + e.getKeyChar());
}
//END OF KEY LISTENER FUNCTIONS
}
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