session in desktop application?

[Punit Jain]

hello , i create a desktop application, when user run that, a login screen appears, and only after successful login he will get access to that software.
but i want afetr user logged in, if he again run that application he should not get login screen again.
so what can i do for this, sessions are there in desktop applications??
also i want to know my login code is okay or not, here is my login code:

import java.sql.*;
public class LoginCheck {
	String loginid;
	String password;
	ResultSet res;
	DbConnection con = new DbConnection();
	Connection conn;
	PreparedStatement ps;
	int i;
	
public boolean Authentication(String loginId, String Password)
{	
	try{
	this.loginid = loginId;
	this.password = Password;
	String query = "SELECT * FROM AdminLogin WHERE loginid='"+loginid+"' AND password = '"+password+"'";
	conn = con.dbConn();
	ps = conn.prepareStatement(query);
	res = ps.executeQuery();
	boolean isCheck=false;
	if(res.next()){
	isCheck=true;
	}
	return isCheck;
	}catch(Exception e){
		e.printStackTrace();
		return false;
	}
}
}

Thank you.

[Tim Moores]

also i want to know my login code is okay or not

It's not, it's wide open to SQL injection attacks. Read up on PreparedStatement.

[Maneesh Godbole]

Punit Jain wrote:
so what can i do for this, sessions are there in desktop applications??

No. But you can use the preference API

[Ranganathan Kaliyur Mannar]

Your login code is very poor. You have declared a PreparedStatement and are calling 'prepareStatement' too, but it is a waste because there is nothing there to prepare in the query.

As for session, I don't think your definition of session is correct. Even in a web app, when I open the browser and log in, my 'session' is alive only till my browser is open. If I close the browser and re-open again, my session is lost and I have to re-login again. So, I think the same would apply to desktop too.

If you want the functionality that you have mentioned, you have to write your own logic, but don't call it a 'session'.

[Punit Jain]

okay i have done changes to my login code, here is what i changed:

String query = "SELECT * FROM AdminLogin WHERE loginid=? AND password = ?";
	conn = con.dbConn();
	ps = conn.prepareStatement(query);
	ps.setString(1, loginid);
	ps.setString(2, password);
	res = ps.executeQuery();

[Punit Jain]

also with my earlier login code i just tried for sql injuction with below login id and password:

user:admin
pass:’ or 1=1–

but it showing me exception only, not giving my user id and password.??

[Tim Moores]

How about this as a password:

'; drop table AdminLogin; --

[Punit Jain]

no it's not dropped my table, it showing me one exception:

java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Characters found after end of SQL statement.
	at sun.jdbc.odbc.JdbcOdbc.createSQLException(Unknown Source)
	at sun.jdbc.odbc.JdbcOdbc.standardError(Unknown Source)
	at sun.jdbc.odbc.JdbcOdbc.SQLPrepare(Unknown Source)
	at sun.jdbc.odbc.JdbcOdbcConnection.prepareStatement(Unknown Source)
	at sun.jdbc.odbc.JdbcOdbcConnection.prepareStatement(Unknown Source)
	at LoginCheck.Authentication(LoginCheck.java:19)
	at LoginUserInterface$1.actionPerformed(LoginUserInterface.java:48)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$000(Unknown Source)
	at java.awt.EventQueue$1.run(Unknown Source)
	at java.awt.EventQueue$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$2.run(Unknown Source)
	at java.awt.EventQueue$2.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

[Tim Moores]

Well, just keep at it and eventually you may succeed.