After login (if succeed) a user will see the result of statement
"select test_column from table_test " execution.
table_test is the only table of database 'test' which i have created in NetBeans 7.0.1.
test_column is the only column.
class 'MySQLTest' creates the gui for login , connects with the database , and finally put the results into a JTable using class 'data'.
I have tried every possible way to retrieve username and password from a gui (class A) and use them in a class (Class B) to connect to the database but i did not succeed, so i ended up with this way. The connection to the database is done within
JButton jbSubmit ActionListener implementation.
Any ideas ?
package mysqltest;
import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.table.*;
/**
*
* @author FOSSES
*/
public class MySQLTest {
public static class Components extends javax.swing.JFrame implements ActionListener{
JTextField jtUserName = new JTextField(20);// JTextField takes the number of columns (width) as a constructor parameter
JPasswordField passwordField = new JPasswordField(10);
Components(){
setTitle("ESTABLISH CONNECTION AND DISPLAY DATA FROM MYSQL DB");
this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
/* GridLayout with 3 rows and 1 column */
GridLayout gl = new GridLayout(3,1);
setLayout(gl);
/*JPanel defaults to a Flow Layout and so components added will have their
*preferred size respected*/
JPanel jpRow1 = new JPanel();
JPanel jpRow2 = new JPanel();
JPanel jpRow3 = new JPanel();
JLabel jlName = new JLabel("username");
jpRow1.add(jlName);
jpRow1.add(jtUserName);/* add the panel to the row within the GridLayout */
add(jpRow1);
JLabel jlPassword = new JLabel("password");
/* add the components to the panel */
jpRow2.add(jlPassword);
jpRow2.add( passwordField);
add(jpRow2);
JButton jbSubmit = new JButton("Submit");
jbSubmit.addActionListener(this);
jpRow3.add(jbSubmit);
add(jpRow3);
setSize(300,300);
setVisible(true);
}
@Override
public void actionPerformed(ActionEvent ae) {
String uname = jtUserName.getText();
char[] pwd = passwordField.getPassword();
String USERNAME = uname; //MySQL Username
String PASSWORD = new String(pwd);
String url = "jdbc:mysql://localhost:3307/test";//Location of Database
try
{
Class.forName ("com.mysql.jdbc.Driver").newInstance();
Connection connection ; // Instantiate a new connection
connection = DriverManager.getConnection(url, USERNAME, PASSWORD);
System.out.println ("Success! Database connection has been established");
Statement statement = connection.createStatement(); //create SQL statement wrapper
statement.execute("drop table table_test");
statement.execute("create table table_test ( test_column integer )"); //create a sample table in the database
for (int i =1; i<11; i++)
statement.execute("insert into table_test values(" + i +")"); //create some test data
statement.execute("select test_column from table_test "); //select data from the newly created table
ResultSet resultset = statement.getResultSet(); //get the resultset
if (resultset != null){ //if the result set exists
int i = 0;
while ( resultset.next() ) //step through the result set
{
i++;//count raws
}
//Define TableModel
TableModel tmodel = new DefaultTableModel(i+1, 1){ };//i+1 raws , 1 column
// JTable Creation
JTable Table = new JTable(tmodel);
//Table.setValueAt("NUMBERS",0,0);
int j = 0;
resultset.beforeFirst();
while (resultset.next()) {
String number = resultset.getString(1);
Table.setValueAt(number,j,0);
j++;
}
Table.getColumnModel().getColumn(0).setHeaderValue("NUMBERS");
data dt = new data(Table);
dt.display();
}//end if
statement.close(); // close the Statement
connection.close(); // close the Connection
setVisible(false);
}
catch (Throwable e){
System.out.println("exception thrown:");
if (e instanceof SQLException)
printSQLError((SQLException) e);
else
e.printStackTrace();
}
}
}
public static void printSQLError(SQLException e)
{
while (e != null)
{
System.out.println(e.toString());
e = e.getNextException();
}
}
public static void main(String[] args) {
Components comp = new Components();
}
}package mysqltest;
/*
*
* @author FOSSES
*/
import java.awt.*;
import javax.swing.*;
public class data extends JFrame {
public JTable table = new JTable();
data(JTable Table)
{
table = Table;
}
public data() {
super("Database Test Frame");
}
public void display() {
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(350, 200);
JScrollPane scrollpane = new JScrollPane(table);
JPanel p1 = new JPanel();
p1.setLayout(new GridLayout(3, 2));
p1.add(new JLabel("Table Data"));
getContentPane().add(p1, BorderLayout.NORTH);
getContentPane().add(scrollpane, BorderLayout.CENTER);
this.setVisible(true);
}
}