Java and SQL server 2012 connection

I am using windows authenication in sql server 2012.

I want to connect java to sql.

I have following code (just for example AND Some code is missing as copied from netbeans you know)

public class app extends javax.swing.JFrame {

public app() {
    initComponents();
}



@SuppressWarnings("unchecked")


private void UserNameActionPerformed(java.awt.event.ActionEvent evt) {

          String username = UserName.getText();
}

private void PasswordActionPerformed(java.awt.event.ActionEvent evt) {

    String password = Password.getText();

}

private void LoginActionPerformed(java.awt.event.ActionEvent evt) {


}


public static void main(String args[]) {


    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new app().setVisible(true);
        }
    });




}

// Variables declaration - do not modify
private javax.swing.JToggleButton Login;
private javax.swing.JPasswordField Password;
private javax.swing.JTextField UserName;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
// End of variables declaration
}

Create database ali;

use ali;


create table Login_System (

		Username VARCHAR(50),
		password VARCHAR(90)

)


SELECT * FROM Login_System;

String userName ="username";
String password ="password";

String url ="jdbc:sqlserver://MYPC\\SQLEXPRESS;databaseName=MYDB";

        try {
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(apps.class.getName()).log(Level.SEVERE, null, ex);
        }
Connection conn = DriverManager.getConnection(url, userName, password);