colfine.java

its a project for library management system

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

import java.sql.*;

public class ColFine extends JInternalFrame implements ActionListener, FocusListener {

	private JPanel pMember = new JPanel ();
	private JLabel lbMemberId, lbMemberName,lbMemberCat;
	
	private JTextField txtMemberId, txtMemberName,txtCat;
	private JButton btnDel, btnCancel;

	private Statement st;		//Statement for Getting the Required Table.
	private ResultSet rs;		//For Getting the Records From Table.
	private long id = 0,heldBooks;		//To Hold the MemberId.
	private int due;
	//Constructor of Class.

	public ColFine (Connection con) {

		//super (Title, Resizable, Closable, Maximizable, Iconifiable)
		super ("Delete Member", false, true, false, true);
		setSize (350, 222);

		//Setting the Form's Labels.

		lbMemberId = new JLabel ("Member Id:");
		lbMemberId.setForeground (Color.black);
		lbMemberId.setBounds (15, 15, 100, 20);
		lbMemberName = new JLabel ("Member Name:");
		lbMemberName.setForeground (Color.black);
		lbMemberName.setBounds (15, 45, 100, 20);
		
		txtMemberId = new JTextField ();
		txtMemberId .setHorizontalAlignment (JTextField.RIGHT);
		txtMemberId.addFocusListener (this);
		txtMemberId .setBounds (125, 15, 200, 25);
		txtMemberName = new JTextField ();
		txtMemberName.setEnabled (false);
		txtMemberName.setBounds (125, 45, 200, 25);
		
		btnDel = new JButton ("Pay Fine.");
		btnDel.setBounds (30, 145, 125, 25);
		btnDel.addActionListener (this);
		btnCancel = new JButton ("Cancel");
		btnCancel.setBounds (185, 145, 125, 25);
		btnCancel.addActionListener (this);

		//Registering the KeyListener to Restrict user to type only Numeric in Numeric Boxes.

		txtMemberId.addKeyListener (new KeyAdapter () {
			public void keyTyped (KeyEvent ke) {
				char c = ke.getKeyChar ();
				if (! ((Character.isDigit (c)) || (c == KeyEvent.VK_BACK_SPACE))) {
					getToolkit().beep ();
					ke.consume ();
				}
			}
		}
		);

		//Adding All the Controls in Panel.

		pMember.setLayout (null);
		pMember.add (lbMemberId);
		pMember.add (lbMemberName);
		
		pMember.add (txtMemberId);
		pMember.add (txtMemberName);
		
		pMember.add (btnDel);
		pMember.add (btnCancel);

		//Adding Panel to Form.

		getContentPane().add (pMember, BorderLayout.CENTER);

		try {
			st = con.createStatement ();	//Creating Statement Object.
		}
		catch (SQLException sqlex) {			//If Problem then Show the User a Message.
 			JOptionPane.showMessageDialog (null, "A Problem Occurs While Loading the Form.");
 			dispose ();				//Closing the Form.
	 	}

		setVisible (true);

	}
	
	public void actionPerformed (ActionEvent ae) {

		Object obj = ae.getSource();

		if (obj == btnDel) {		//If Delete Button Pressed.

			if (txtMemberId.getText().equals ("")) {
				JOptionPane.showMessageDialog (this, "Member's Id not Provided.");
				txtMemberId.requestFocus ();
			}
			else
			{
				
				
				int reply = JOptionPane.showConfirmDialog (this, 
				"Will you pay the dues of" + due + " Rupees?",
				"LibrarySystem - Delete Member", JOptionPane.YES_NO_OPTION, JOptionPane.PLAIN_MESSAGE);

				//Check the User Selection.
				if (reply == JOptionPane.YES_OPTION) {			//If User's Choice Yes then.

					try {	//DELETE Query to Delete the Record from Table.
						String q = "Update Members Set Mbdues ="+ 0+ "WHERE id = " + id + "";
						txtClear ();				//Clearing the TextFields.
						JOptionPane.showMessageDialog (this, "Fine Collected");
						ResultSet rs = st.executeQuery (q);	//Executing the Query.
					}
					catch (SQLException sqlex) {System.out.println("problem"); }

				}
				//If User's Choice No then Do Nothing Return to Program.
				else if (reply == JOptionPane.NO_OPTION) { }
			}

		}

		if (obj == btnCancel) {		//If Cancel Button Pressed Unload the From.

			setVisible (false);
			dispose();

		}

	}

	//OverRidding the FocusListener Class Function.

	public void focusGained (FocusEvent fe) { }

	public void focusLost (FocusEvent fe) {

		if (txtMemberId.getText().equals ("")) {	//If TextField is Empty.
		}
		else {
			id = Integer.parseInt (txtMemberId.getText ());	//Converting String to Numeric.
			long memberNo,memtype;					//Use for Comparing the Member's Id.
			boolean found = false;				//To Confirm the Member's Id Existance.

			try {	//SELECT Query to Retrieved the Record.
				String q = "SELECT * FROM Members WHERE id = " + id + "";
				ResultSet rs = st.executeQuery (q);	//Executing the Query.
				rs.next ();				//Moving towards the Record.
				memberNo = rs.getLong ("id");	//Storing the Record.
				memtype=rs.getLong("Mcat");
				due=rs.getInt(6);
				if (memberNo == id) {			//If Record Found then Display Records.
					
					found = true;
					txtMemberId.setText ("" + id);
					txtMemberName.setText ("" + rs.getString ("MName"));
					
				}
				else {
					found = false;
				}
			}
			catch (SQLException sqlex) {
				if (found == false) {
					txtClear ();		//Clearing the TextFields.
					JOptionPane.showMessageDialog (this, "Record not Found.");
				}
			}

		}

	}

	//Function Use to Clear All the TextFields of Form.

	private void txtClear () {

		txtMemberId.setText ("");
		txtMemberName.setText ("");
		txtCat.setText("");
		txtMemberId.requestFocus ();

	}

}