JDBC Example to show records on JTable
import java.awt.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.table.*;
public class JTableDatabase
{
public static void main(String[] args)
{
Vector columnNames = new Vector();
Vector data = new Vector();
JPanel p=new JPanel();
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection("jdbc:odbc:test");
String sql = "Select * from product";
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
for (int i = 1; i <= columns; i++) {
columnNames.addElement( md.getColumnName(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 e){
System.out.println(e);
}
JTable table = new JTable(data, columnNames);
TableColumn col;
for (int i = 0; i < table.getColumnCount(); i++) {
col = table.getColumnModel().getColumn(i);
col.setMaxWidth(250);
}
JScrollPane scrollPane = new JScrollPane( table );
p.add( scrollPane );
JFrame f=new JFrame();
f.add(p);
f.setSize(600,400);
f.setVisible(true);
}
}
Out of the above program is as following image…
Java Program to demonstrate Linked List
import java.util.*;
public class LinkedListExa
{
public static void main(String args[])
{
LinkedList<String> linkedlist = new LinkedList<String>();
linkedlist.add("Beta");
linkedlist.add("Cupcake");
linkedlist.add("Donut");
linkedlist.add("Eclair");
linkedlist.add("Froyo");
linkedlist.add("Gingerbread");
linkedlist.add("Honeycomb");
linkedlist.add("Ice Cream Sandwich");
linkedlist.add("Jellybean");
linkedlist.add("KitKat");
System.out.println("Linked List Content: " +linkedlist);
/*Adding First and Last Element */
linkedlist.addFirst("Alpha");
linkedlist.addLast("Lollipop");
System.out.println("LinkedList Content after addition: " +linkedlist);
Object firstvar = linkedlist.get(0);
System.out.println("First element: " +firstvar);
linkedlist.set(0, "Changed first item");
Object firstvar2 = linkedlist.get(0);
System.out.println("First element after update by set method: " +firstvar2);
/*Remove first and last element*/
linkedlist.removeFirst();
linkedlist.removeLast();
System.out.println("LinkedList after deletion of first and last element: " +linkedlist);
/* Add to a Position and remove from a position*/
linkedlist.add(0, "Mango");
linkedlist.remove(2);
System.out.println("Final Content: " +linkedlist);
}
}
JDBC program to demonstrate Login program.
//package awt;
import javax.swing.*;
import java.awt.event.*;
import java.sql.*;
public class Login {
Connection con;
Statement st;
ResultSet rs;
JFrame f = new JFrame("User Login !");
JLabel l = new JLabel("Username : ");
JLabel l1= new JLabel("Password : ");
JTextField t = new JTextField (10);
JTextField t1 = new JTextField (10);
JButton b = new JButton("Login");
public Login()
{
connect();
frame();
}
public void connect()
{
try {
String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
Class.forName(driver);
String db = "jdbc:odbc:dsntest";
con = DriverManager.getConnection(db);
st = con.createStatement();
}catch (Exception e )
{
}
}
public void frame()
{
f.setSize(600,400);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
JPanel p = new JPanel();
p.add(l);
p.add(t);
p.add(l1);
p.add(t1);
p.add(b);
f.add(p);
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
try
{
String user =t.getText().trim();
String pass = t1.getText().trim();
String sql = "select usernm, pass from login_tab where
usernm = '" + user +"'and pass= '"+ pass +"'";
rs = st.executeQuery(sql);
int count = 0;
while(rs.next()){
count = count + 1;
}
if (count == 1 )
{
JOptionPane.showMessageDialog(null,"User Found ,
Access Granted! ");
}
else if ( count > 1 )
{
JOptionPane.showMessageDialog(null,"Duplicate User
, Access Denied! ");
}
else
{
JOptionPane.showMessageDialog(null," User Does Not
Exist ! ");
}
} catch(Exception ex ){
}
}
});
}
public static void main(String[] args) {
new Login();
}
}
Output is…
Java Swing program (JDBC) Login to MySQL Database.
import javax.swing.*;
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
class LoginDemo extends JFrame{
JButton SUBMIT;
JLabel label1,label2;
final JTextField text1,text2;
LoginDemo()
{
setTitle("Login Form");
setLayout(null);
label1 = new JLabel();
label1.setText("Username:");
text1 = new JTextField(15);
label2 = new JLabel();
label2.setText("Password:");
text2 = new JPasswordField(15);
SUBMIT=new JButton("SUBMIT");
label1.setBounds(350,100,100,20);
text1.setBounds(450,100,200,20);
label2.setBounds(350,130,100,20);
text2.setBounds(450,130,200,20);
SUBMIT.setBounds(450,160,100,20);
add(label1);
add(text1);
add(label2);
add(text2);
add(SUBMIT);
setVisible(true);
setSize(1024,768);
SUBMIT.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
String value1=text1.getText();
String value2=text2.getText();
try{
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:90/test", "root", "");
Statement st=con.createStatement();
ResultSet rs=st.executeQuery("select * from login where username='"+value1+"' and password='"+value2+"'");
String uname="",pass="";
if(rs.next()){
uname=rs.getString("username");
pass=rs.getString("password");
}
if(value1.equals("") && value2.equals("")) {
JOptionPane.showMessageDialog(null,"Enter login name or password","Error",JOptionPane.ERROR_MESSAGE);
}
else if(value1.equals(uname) && value2.equals(pass)) {
NextPage page=new NextPage(uname);
page.setVisible(true);
}
else if (!value1.equals(uname) && !value2.equals(pass)) {
text1.setText("");
text2.setText("");
}
}
catch(Exception e){}
}
});
}
public static void main(String arg[]){
new LoginDemo();
}
}
