Java swings

[anup v]

This is my code, i want to know by adding or modifying what can i have my code refresh the JTable everytime its accessed.

package library2;

import java.awt.Dimens ion;
import java.awt.FlowLa yout;
import java.awt.GridLa yout;
import java.awt.Image;
import java.awt.event. ActionEvent;
import java.awt.event. ActionListener;
import java.sql.Connec tion;
import java.sql.Driver Manager;
import java.sql.Result Set;
import java.sql.Result SetMetaData;
import java.sql.Statem ent;
import java.util.Vecto r;

import javax.swing.JBu tton;
import javax.swing.JFr ame;
import javax.swing.JLa bel;
import javax.swing.JPa nel;
import javax.swing.JSc rollPane;
import javax.swing.JTa ble;
import javax.swing.eve nt.ListSelectio nEvent;
import javax.swing.eve nt.TableModelEv ent;
import javax.swing.eve nt.TableModelLi stener;
import javax.swing.tab le.DefaultTable Model;
import javax.swing.tab le.TableColumn;

public class home extends JFrame {

protected static final ListSelectionEv ent ListSelectionEv ent = null;

static JFrame mainfram = new JFrame("welcome to library");

static JFrame f2 = new JFrame("LIST OF THE BOOKS");
static JButton b1 = new JButton("Add A New Book");
static JButton b2 = new JButton("Modify The Book Details");
static JButton b3 = new JButton("List Of Available Books");
static JButton lihp = new JButton("HOMEPA GE");
static JLabel l1 = new JLabel(
".............W ELCOME TO LIBRARY........ ......", JLabel.CENTER);
static JLabel l2 = new JLabel("HAVE A GREAT DAY :)))", JLabel.CENTER);
static JPanel p1 = new JPanel(new GridLayout(5, 3, 40, 40));

public home() {
p1.setVisible(t rue);
b1.setSize(50, 100);

mainfram.setSiz e(800, 400);
mainfram.add(p1 );
mainfram.setVis ible(true);

// f2.add(lihp);

}

public static void main(String args[]) {
{

b1.addActionLis tener(new ActionListener( ) {
public void actionPerformed (ActionEvent ae) {
mainfram.setVis ible(false);
mainfram.setDef aultCloseOperat ion(JFrame.EXIT _ON_CLOSE);

Addingbook ab = new Addingbook();
// ab.setVisible(t rue);
// ab.setSize(800, 400);

}

});

b2.addActionLis tener(new ActionListener( ) {
public void actionPerformed (ActionEvent ae) {
mainfram.setVis ible(false);
mainfram.setDef aultCloseOperat ion(JFrame.EXIT _ON_CLOSE);

listing li = new listing();
// li.setVisible(t rue);
// li.setSize(800, 400);

}

});

b3.addActionLis tener(new ActionListener( ) {
public void actionPerformed (ActionEvent ae) {

Vector columnNames = new Vector();
Vector data = new Vector();
data.clear();
JPanel p = new JPanel(); /* (new GridLayout(2,1, 10,10) */
p.setBounds(0, 0, 400, 300);
JLabel l = new JLabel();

try {

// Connection con =
// DriverManager.g etConnection("J dbc:Odbc:test") ;

String sql = "select *from books";
String cs = "jdbc:mysql ://localhost:3306/test";
String user = "root";
String pwd = "thbs123!";
Class.forName(" com.mysql.jdbc. Driver").newIns tance();
Connection con = DriverManager.g etConnection(cs , user,
pwd);

Statement stmt = con.createState ment();
ResultSet rs = stmt.executeQue ry(sql);
ResultSetMetaDa ta md = rs.getMetaData( );
// md.getServerExe cutions();
int columns = md.getColumnCou nt();
for (int i = 1; i <= columns; i++) {
columnNames.add Element(md.getC olumnName(i));
}
while (rs.next()) {
Vector row = new Vector(columns) ;
for (int i = 1; i <= columns; i++) {
row.addElement( rs.getObject(i) );

}
data.addElement (row);
}
rs.close();
stmt.close();
} catch (Exception e1) {
System.out.prin tln(e1);
}

JTable table = new JTable(data, columnNames);

//data = getServerExecut ions();
//table.fireTable DataChanged();
// table.getModel( ).setModel();
// table.valueChan ged(ListSelecti onEvent);




//data(set);
// columnNames();

TableColumn col;
for (int i = 0; i < table.getColumn Count(); i++) {
col = table.getColumn Model().getColu mn(i);
col.setMaxWidth (999);

}

JScrollPane scrollPane = new JScrollPane(tab le);
table.setPrefer redScrollableVi ewportSize(new Dimension(750,
275));
p.setVisible(tr ue);
p.add(l);

p.add(scrollPan e);
// p.add(lihp);

f2.add(p);

f2.setSize(800, 400);
f2.setVisible(t rue);

}
});
f2.add(lihp);
lihp.setBounds( 320, 320, 120, 30);
lihp.addActionL istener(new ActionListener( ) {
public void actionPerformed (ActionEvent ae) {

mainfram.setVis ible(true);
f2.setVisible(f alse);
// f2.setDefaultCl oseOperation(EX IT_ON_CLOSE);

}
});

mainfram.setLay out(new FlowLayout());
// mainfram.imageU pdate(Blue, arg1, arg2, arg3, arg4, arg5)
mainfram.setVis ible(true);
mainfram.setSiz e(800, 400);
p1.add(new JLabel(""));
p1.add(l1);
p1.add(new JLabel(""));
p1.add(new JLabel(""));
p1.add(b1);

p1.add(new JLabel(""));
p1.add(new JLabel(""));
p1.add(b2);
p1.add(new JLabel(""));
p1.add(new JLabel(""));
p1.add(b3);
p1.add(new JLabel(""));
p1.add(new JLabel(""));
p1.add(l2);
p1.add(new JLabel(""));
mainfram.add(p1 );

// f2.setLayout(ne w FlowLayout());

f2.setResizable (false);

}

}

public void setVisible(bool ean b) {
// TODO Auto-generated method stub

}
}

[rotaryfreak]

if you want to have your table reflect changes once the user manipulates it, you can apply the observer pattern

http://en.wikipedia.org/wiki/Observer_pattern

or you can simply call update() or updateUI() on your JTable every time the user manipulates the table.

i would also recommend that you refactor some of your code into separate classes so it's a little more organized. For example, i would have one class that deals with sql connections, another class for database manipulation, another class for user interface creation and another class for handling what happens when the action listeners are clicked.

hope this helps