Java

17-Jul-13 20:11

Same question happened before to me. refer the following link. u ll find the answer Null point exception[^]

mali_angel3-Jul-13 18:16

Re: Login process Always false..cannot find the error

3-Jul-13 18:16

Im goin to a online bank assignment in java using DAO technigues with mysql.it is not printing an error or exception.but it always jumps to false part.here my code, please tell where I go wrong and how to fix it..

Login.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>

<title>Insert title here

Login
UserName:
Password:

<%=request.getAttribute("loginMsg") %>

UserServlet.java

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
String operation = request.getParameter("operation");
if(operation!=null && operation.equalsIgnoreCase("login")){
loginDetail(request,response);
}else if(operation!=null && operation.equalsIgnoreCase("login")){
logout(request,response);
}
}

private void loginDetail(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
User u = new User();
UserService us =new UserServiceImpl() ;

String Uname = request.getParameter("txtUname");
String Pwrd = request.getParameter("txtPwrd");

u.setUname(Uname);
u.setPwrd(Pwrd);

System.out.println(Uname+""+Pwrd);
try {
if(us.Userlogin(u.getUname(),u.getPwrd())){
String message = "Thank you, " + Uname +"..You are now logged into the system";
HttpSession session = request.getSession(true);
session.setAttribute("username", Uname);
session.setAttribute("password", Pwrd);
response.setContentType("text/html");
request.setAttribute("message", message);
request.getRequestDispatcher("/Menu.jsp").forward(request, response);
}else {
String message = "You have to register first or check Your user name password again!";
request.setAttribute("loginMsg", message);
RequestDispatcher rd = getServletContext().getRequestDispatcher("/Login.jsp");
rd.forward(request, response);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

UserServiceImpl.java

@Override
public boolean Userlogin(String Uname, String Pwrd) {
// TODO Auto-generated method stub
boolean result=false;
UserDAO udoi = new UserDAOImpl();
User user = new User();
System.out.println("ppp");
user.setUname(Uname);
user.setPwrd(Pwrd);
System.out.println("//////");
System.out.println(user.getUname()+user.getPwrd());
if(user!=null){
System.out.println(user.getUname()+user.getPwrd());
result = udoi.getLoginDetail(Uname, Pwrd);
//result=true;
}
return result;
}

UserDAOImpl.java

@Override
public boolean getLoginDetail(String Uname, String Pwrd) {
// TODO Auto-generated method stub
System.out.println(Uname+"++"+Pwrd);
Connection conn=null;
ResultSet rs=null;
boolean SUCCESS=false;
try {
conn=getConnection();
//String sql="SELECT * FROM login WHERE UserName='amal' and password='secret' ";
String sql="SELECT * FROM login WHERE UserName='" + Uname + "' and Password='"+ Pwrd + "' ";
System.out.println(sql);
Statement stmt=conn.createStatement();
rs = stmt.executeQuery(sql);
System.out.println("ddddddddddddddddd" + rs==null);
System.out.println("sssssssssssssssss" + rs.next());
while(rs.next()) {
System.out.println(Uname+"*_*"+Pwrd);
String uname=rs.getString("UserName");
String password=rs.getString("Password");
System.out.println(Uname+"***"+Pwrd);
if ((uname.equals(Uname)) && (password.equals(Pwrd))){
SUCCESS=true;
}else {
SUCCESS=false;
}

}
}
catch (Exception e){
e.printStackTrace();
}finally {
try {
conn.close();
rs.close();
} catch (SQLException ex) {
Logger.getLogger(AccountDAOImpl.class.getName()).log(Level.SEVERE, null, ex);
}
}
return SUCCESS;
}

private Connection getConnection() {
// TODO Auto-generated method stub
ConnectionFactory cf = new ConnectionFactory();
Connection conn = null;
try {
conn = cf.getConnection();
} catch (SQLException ex) {
Logger.getLogger(AccountDAOImpl.class.getName()).log(Level.SEVERE, null, ex);
}
return conn;
}

EveryImpl file has it's interfaceclass.please tell me where I go wrong. Thank you!

Shubhashish_Mandal3-Jul-13 19:53

3-Jul-13 19:53

Cross post.

Regards
Shubhashish

mali_angel3-Jul-13 17:22

Re: Login process Always false..cannot find the error

3-Jul-13 17:22

XML

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
    <form name="input" action="login" method="post">
    <h1>Login</h1><br>
    UserName:        <input type="text" name="txtUname"><br>
    Password:        <input type="password" name="txtPwrd"><br>
    <input type="submit" value="Login" onclick= <a href="main/Servelet"</a> >
    <input type="hidden" name="operation" value="login">
    <p><%=request.getAttribute("loginMsg") %></p>
    </form>
</body>
</html>

UserServlet.java

Java

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		String operation = request.getParameter("operation");
		if(operation!=null && operation.equalsIgnoreCase("login")){
			loginDetail(request,response);
		}else if(operation!=null && operation.equalsIgnoreCase("login")){
			logout(request,response);
		}
	}

Java

private void loginDetail(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{		
		User u = new User();
		UserService us =new UserServiceImpl() ;
		
		String Uname = request.getParameter("txtUname");		
		String Pwrd = request.getParameter("txtPwrd");	
		
		u.setUname(Uname);
		u.setPwrd(Pwrd);
		
		System.out.println(Uname+""+Pwrd);
		try {
			if(us.Userlogin(u.getUname(),u.getPwrd())){     
				String message = "Thank you, " + Uname +"..You are now logged into the system";
				HttpSession session = request.getSession(true);
			    session.setAttribute("username", Uname);
			    session.setAttribute("password", Pwrd);	 		
		        response.setContentType("text/html");
			    request.setAttribute("message", message);
				request.getRequestDispatcher("/Menu.jsp").forward(request, response);
			}else {
				String message = "You have to register first or check Your user name password again!";				
				request.setAttribute("loginMsg", message);
				RequestDispatcher rd = getServletContext().getRequestDispatcher("/Login.jsp");
				rd.forward(request, response); 
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block			
			e.printStackTrace();
		}
	}

UserServiceImpl.java

Java

@Override
	public boolean Userlogin(String Uname, String Pwrd) {
		// TODO Auto-generated method stub
		boolean result=false;   
        UserDAO udoi = new UserDAOImpl();
        User user = new User();
        System.out.println("ppp");
        user.setUname(Uname);
        user.setPwrd(Pwrd);
        System.out.println("//////");
        System.out.println(user.getUname()+user.getPwrd());
        if(user!=null){
        	System.out.println(user.getUname()+user.getPwrd());
        	result = udoi.getLoginDetail(Uname, Pwrd); 
            //result=true;       
        }
		return result;
	}

UserDAOImpl.java

Java

@Override
	public boolean getLoginDetail(String Uname, String Pwrd) {
		// TODO Auto-generated method stub
		System.out.println(Uname+"++"+Pwrd);
		Connection conn=null;
	    ResultSet rs=null;	
	    boolean SUCCESS=false;
	    try {
	    	conn=getConnection();
	    	//String sql="SELECT * FROM login WHERE UserName='amal' and password='secret' ";
	    	String sql="SELECT * FROM login WHERE UserName='" + Uname + "' and Password='"+ Pwrd + "' ";
	    	System.out.println(sql);
	    	Statement stmt=conn.createStatement();
	    	rs = stmt.executeQuery(sql);
	    	System.out.println("ddddddddddddddddd" + rs==null);
	    	System.out.println("sssssssssssssssss" + rs.next());
	        while(rs.next()) {
	        	System.out.println(Uname+"*_*"+Pwrd);
	            String uname=rs.getString("UserName");
	            String password=rs.getString("Password");
	            System.out.println(Uname+"***"+Pwrd);
	            if ((uname.equals(Uname)) && (password.equals(Pwrd))){
	            	SUCCESS=true;
	            }else {
	            	SUCCESS=false;
            }

	        }
	    }
	    catch (Exception e){
	    	e.printStackTrace();
        }finally {
            try {
                conn.close();
                rs.close();
            } catch (SQLException ex) {
                Logger.getLogger(AccountDAOImpl.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
		return SUCCESS;
	}

	private Connection getConnection() {
		// TODO Auto-generated method stub
		ConnectionFactory cf = new ConnectionFactory();
        Connection conn = null;
        try {
            conn = cf.getConnection();
        } catch (SQLException ex) {
            Logger.getLogger(AccountDAOImpl.class.getName()).log(Level.SEVERE, null, ex);
        }        
        return conn;
	}

EveryImpl file has it's interfaceclass.please tell me where I go wrong. Thank you!

mali_angel3-Jul-13 17:28

Re: Login process Always false..cannot find the error

3-Jul-13 17:28

ppp
//////
2222
2222
22++22
Welcome
Connected
SELECT * FROM login WHERE UserName='22' and Password='22'
false
ssssssssssssssssstrue

This is the Output..when i enter a true login details..Still couldn;t find the error..

Shubhashish_Mandal3-Jul-13 19:40

Re: Login process Always false..cannot find the error

3-Jul-13 19:40

The problem is here. Your ResultSet return one row. First rs.next() point to the actual row returned. Again in while loop you use rs.next() so your resultSet move to the next row, and which has no row value(first row already read) so it return false and thus skip the while loop.

Java

System.out.println("sssssssssssssssss" + rs.next());
while(rs.next()) {

Remove the sout.

XML

<pre lang="java">
while(rs.next()) {
</pre>

Regards
Shubhashish

mali_angel3-Jul-13 19:51

Re: Login process Always false..cannot find the error

3-Jul-13 19:51

Thank u soo much..it is working perfectly now Big Grin | :-D

Shubhashish_Mandal3-Jul-13 19:54

actionPerformed in another class

3-Jul-13 19:54

welcome

Regards
Shubhashish

chdboy1-Jul-13 19:27

chdboy

1-Jul-13 19:27

How can I use another class actionPerformed in another main class?
I want to use this class actionperformed

Java

import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import java.awt.Container;
import javax.swing.JOptionPane;
import java.awt.Frame;
import java.awt.event.*;
import java.io.IOException;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SpringLayout;

public class SpringSample extends Frame implements ActionListener

{
		 JLabel F_namelbl = new JLabel("Username: ");
	    JLabel L_namelbl = new JLabel("Password: ");
	    JTextField tf_Fname = new JTextField(15);
	    JPasswordField tf_Lname = new JPasswordField(15);
	    JLabel Lbl_HW = new JLabel("< Login Area >");
	    JButton Btn = new JButton("Login");
	    JButton btn_cancel = new JButton("Cancel");
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	SpringSample()
	{
		
	    
		 JFrame frame = new JFrame("Login Area!");		 
		    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		    Container contentPane = frame.getContentPane();
		    JPanel p = new JPanel(new SpringLayout());
		    SpringLayout layout = (new SpringLayout());
		    contentPane.setLayout(layout);		   
		    JPanel p1=new JPanel();    
		   
		     
		    //--------------------------------------------------------------------------------------------------------------------
		    
		    //---------------------------------------------------------------------------------------------------------------------
		    /*Adding Components to the ContentPane */
		    frame.add(p1);
		    contentPane.add(F_namelbl);
		    contentPane.add(L_namelbl);
		    contentPane.add(tf_Fname);
		    contentPane.add(tf_Lname);
		    contentPane.add(Lbl_HW);
		    contentPane.add(Btn);
		    contentPane.add(btn_cancel);
		    	    
		      //--------------------------------------------------------------------------------------------------------------------
		    /*Lay out Components according to the position and coordinates on the SpringLayout*/
		    
		    layout.putConstraint(SpringLayout.WEST, Lbl_HW, 140, SpringLayout.WEST, contentPane);
		    layout.putConstraint(SpringLayout.NORTH, Lbl_HW, 0, SpringLayout.NORTH, contentPane);    
		    layout.putConstraint(SpringLayout.WEST, Lbl_HW, 140, SpringLayout.WEST, contentPane);
		    layout.putConstraint(SpringLayout.NORTH, Lbl_HW, 0, SpringLayout.NORTH, contentPane);
		    layout.putConstraint(SpringLayout.WEST, F_namelbl, 30, SpringLayout.WEST, contentPane);
		    layout.putConstraint(SpringLayout.NORTH, F_namelbl, 25, SpringLayout.NORTH, contentPane);
		    layout.putConstraint(SpringLayout.WEST, L_namelbl, 30, SpringLayout.WEST, contentPane);
		    layout.putConstraint(SpringLayout.NORTH, L_namelbl, 50, SpringLayout.NORTH, contentPane);
		    layout.putConstraint(SpringLayout.NORTH, tf_Fname, 25, SpringLayout.NORTH, contentPane);
		    layout.putConstraint(SpringLayout.WEST, tf_Fname, 15, SpringLayout.EAST, F_namelbl);
		    layout.putConstraint(SpringLayout.NORTH, tf_Lname, 50, SpringLayout.NORTH, contentPane);
		    layout.putConstraint(SpringLayout.WEST, tf_Lname, 15, SpringLayout.EAST, F_namelbl);
		    layout.putConstraint(SpringLayout.NORTH, Btn, 80, SpringLayout.NORTH, contentPane);
		    layout.putConstraint(SpringLayout.WEST, Btn, 110, SpringLayout.WEST, contentPane);
		    layout.putConstraint(SpringLayout.NORTH, btn_cancel, 80, SpringLayout.NORTH, p1);
		    layout.putConstraint(SpringLayout.WEST, btn_cancel, 200, SpringLayout.WEST, p1);	    
		    
		    //---------------------------------------------------------------------------------------------------------------------
		    /*Adding Action Listener/Action*/
		    btn_cancel.addActionListener(this);
		    Btn.addActionListener(this);
		    
		    //------------------------------------------------------------------------------------------------------------------------
		    /*Setting up JFrame*/
		    
		    frame.pack();
		    frame.setSize(350, 200);
		    frame.setLocationRelativeTo(null); //to appear frame in the center of the window screen
		    //setLocation(700,280);
		    frame.setVisible(true);	
	}
  public static void main(String args[]) 
  {	 
	  
    new SpringSample();    
   Connectionstring();  
  
    
    try {						 
		insertRecordIntoDbUserTable();
		selectfromdb();
	} 
	catch (SQLException e)
	{

		System.out.println(e.getMessage());

	}  
	  
  }
  //connection string method
  static Connection Connectionstring()
 	{		
 		Connection con = null;
 		try {
			Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		} catch (ClassNotFoundException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
 		String conUrl = "jdbc:sqlserver://localhost:1433; databaseName=paytest; user=PC; password=; integratedSecurity=true;";
 		
 		try 
 		{
 				 con = DriverManager.getConnection(conUrl);
 				 JOptionPane.showMessageDialog(null,"Connection is open!","Connection",JOptionPane.WARNING_MESSAGE);
 				 
 				 }
 		catch (SQLException e)
 		{
 			
 			e.printStackTrace();
 		}		
 		return con;
 		
 	}
  
  private static void insertRecordIntoDbUserTable() throws SQLException
	{
		Connection con = null;
		Statement statement = null;
		String insertTableSQL = "INSERT INTO LoginDetails" + "(Username, Password) " + "VALUES" + "('user1','user1')";
		try 
		{
			con = Connectionstring();
			statement = con.createStatement(); 
			System.out.println(insertTableSQL);			
			statement.executeUpdate(insertTableSQL);			
			
			JOptionPane.showMessageDialog(null,"Your Data has been Inserted","Data Inserted",JOptionPane.WARNING_MESSAGE);
		} 
		catch (SQLException e)
		{

			System.out.println(e.getMessage()); 
		} 
		finally 
		{

			if (statement != null)
			{
				statement.close();
				
				JOptionPane.showMessageDialog(null,"Statement is closed","Statement",JOptionPane.WARNING_MESSAGE);
			}

			if (con != null)
			{
				con.close();
				
				JOptionPane.showMessageDialog(null,"Connection is closed!","Connection",JOptionPane.WARNING_MESSAGE);
			}

		}
		
		
	}
 
  private static void selectfromdb() throws SQLException
	{		
	    Statement stmt = Connectionstring().createStatement();
		ResultSet rs = stmt.executeQuery("SELECT Username,Password FROM LoginDetails");
		while (rs.next())
		{
			  String lastName = rs.getString("Username");
			  String Pass = rs.getString("Password");
			  System.out.println(lastName + "" + Pass + "\n");
			 
			}		
	} 

 public void actionPerformed(ActionEvent e) 
{
	 
	if(e.getSource() == btn_cancel)
	{
		JOptionPane.showMessageDialog(null,"You have clicked on Cancel","button cancel",JOptionPane.WARNING_MESSAGE);
	}
	else if(e.getSource() == Btn)
	{
		//SpringSample sp = new SpringSample();
		//DBConnectionstring db = new DBConnectionstring();
		JOptionPane.showMessageDialog(null,"You have clicked login","button login",JOptionPane.WARNING_MESSAGE);		
		
	}
	
	

}
 
 //NEW CONNECTION STRING(CLASS) FOR JDBC CONNECTION I HOPE THIS WORKS
 
 
 
 
 
}

I want to use in this class

Java

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.JOptionPane;
public abstract class ConnectionDB 
{	
	
	/**
	 * @param args
	 */
	public static void main(String[] args)
	{	
		SpringSample sp = new SpringSample();
		
		try {						 
			insertRecordIntoDbUserTable();
			selectfromdb();
		} 
		catch (SQLException e)
		{ 
			System.out.println(e.getMessage()); 
		}
}		
	private static void insertRecordIntoDbUserTable() throws SQLException
	{
		Connection con = null;
		Statement statement = null;
		String insertTableSQL = "INSERT INTO LoginDetails" + "(Username, Password) " + "VALUES" + "('null2','tf_Lname')";
		try 
		{
			con = DBConnectionstring();
			statement = con.createStatement(); 
			System.out.println(insertTableSQL);			
			statement.executeUpdate(insertTableSQL);			
			
			JOptionPane.showMessageDialog(null,"Your Data has been Inserted","Data Inserted",JOptionPane.WARNING_MESSAGE);
		} 
		catch (SQLException e)
		{
 
			System.out.println(e.getMessage()); 
		} 
		finally 
		{ 
			if (statement != null)
			{
				statement.close();				
				JOptionPane.showMessageDialog(null,"Statement is closed","Statement",JOptionPane.WARNING_MESSAGE);
			}
 
			if (con != null)
			{
				con.close();				
				JOptionPane.showMessageDialog(null,"Connection is closed!","Connection",JOptionPane.WARNING_MESSAGE);
			} 
		}		
	}	
	private static void selectfromdb() throws SQLException
	{		
	    Statement stmt = DBConnectionstring().createStatement();
		ResultSet rs = stmt.executeQuery("SELECT Username,Password FROM LoginDetails");
		while (rs.next())
		{
			  String lastName = rs.getString("Username");
			  String Pass = rs.getString("Password");
			  System.out.println(lastName + "" + Pass + "\n");			 
			}		
	}	
	 static Connection DBConnectionstring()
	{		
		Connection con = null;
		String conUrl = "jdbc:sqlserver://localhost:1433; databaseName=paytest; user=PC; password=; integratedSecurity=true;";		
		try 
		{
				 con = DriverManager.getConnection(conUrl);				
				 JOptionPane.showMessageDialog(null,"Connection is open!","Connection",JOptionPane.WARNING_MESSAGE);				 
				 }
		catch (SQLException e)
		{			
			e.printStackTrace();
		}		
		return con;		
	}
	 
	 
	 
	 
	}

How can I do that?

Re: actionPerformed in another class

Richard MacCutchan1-Jul-13 20:46

Re: actionPerformed in another class

1-Jul-13 20:46

Rather than dumping a lot of code, try explaining your problem in clear terms. If you need to call a method of a class then create an object of that class and call the method as normal. however, if that is not your question then please clarify.

Use the best guess

Shubhashish_Mandal3-Jul-13 19:48

why java in linux has outstanding performance even jvm slow it down?

3-Jul-13 19:48

You can only register an event handler to an event source. So your first class is an event handler. And there fore you can use this to any of the event source which trigger that event. Something like this.

Java

class Handler implements ActionPerformed{

   public void actionPerformed(ActionEvent e) {}
   }
}
class Source {
   p s v main(){
     JButton bt = new Jbutton("Ok");
      bt.addActionListener(new Handler());
   }
}

Regards
Shubhashish

crunchor28-Jun-13 17:55

Re: why java in linux has outstanding performance even jvm slow it down?

28-Jun-13 17:55

Jvm has be written to have good speed in linux?

Richard MacCutchan28-Jun-13 23:19

Re: why java in linux has outstanding performance even jvm slow it down?

28-Jun-13 23:19

Please stop posting these questions. you have been told plenty of times that they are not valid for the programming forums.

Use the best guess

crunchor28-Jun-13 23:22

Re: why java in linux has outstanding performance even jvm slow it down?

28-Jun-13 23:22

You are a funny person, why do I need to care what you said? This is a very good topic to discuss for anyone interest in Java, stop being funny alright?

NotPolitcallyCorrect29-Jun-13 0:51

NotPolitcallyCorrect

29-Jun-13 0:51

crunchor wrote:
Jvm has be written to have good speed in linux?

Of course it was, Do you really think that it would have been written to have poor performance? Sleepy | :zzz:

Message Closed

27-Jun-13 17:11

27-Jun-13 17:11

Message Closed

Richard MacCutchan27-Jun-13 21:23

27-Jun-13 21:23

Please stop posting these irrelevant questions here. If you have a problem with another website then complain to that site's adminstrators. Once again this post has nothing to do with programming or Java. You are getting seriously close to being removed from this site.

Use the best guess

crunchor27-Jun-13 21:40

27-Jun-13 21:40

coeproject is a .net focus forum, I ask for what is happening in somewhere about java is not a problem. No one really care about java in this forum anyway.

Richard MacCutchan27-Jun-13 22:33

27-Jun-13 22:33

Please read http://www.codeproject.com/Messages/3137511/Forum-Guidelines-PLEASE-READ.aspx[^] carefully, and stop abusing these forums.

Use the best guess

Pete O'Hanlon27-Jun-13 22:59

Pete O'Hanlon

27-Jun-13 22:59

Richard. He's trolling. I suggest that we apply the official response to trolls.

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Richard MacCutchan27-Jun-13 23:40

27-Jun-13 23:40

I agree, let the voting commence.

Use the best guess

crunchor27-Jun-13 23:00

27-Jun-13 23:00

I think you forgot to read this:
Do not be abusive, offensive, inappropriate or harass anyone on the boards. Doing so will get you kicked off and banned. Play nice.