here is no specidied main()
here is no specidied main() so you get nullpointer error
Help on changing password code by user using java
Submitted by kine on Saturday, May 29, 2010 - 17:49.
Hello Sir.
I have difficulty writting out the code to reset user password in the database after login into the application.
Here is my code
char[] oldPass = jPasswordField1.getPassword();
String strOldPass = new String(oldPass);
char[] newPass = jPasswordField2.getPassword();
String strNewPass = new String(newPass);
char[] confPass = jPasswordField3.getPassword();
String strConfPass = new String(confPass);
try
{
Inventory objInven = new Inventory();//creating of the objectof the connection in class Inventory.
Statement stmt = objinven.con.createStatement();
ResultSet rs = stmt.getResult();
while(rs.next())
{
if(rs.getsring("Password").equals(strOldPass))
{
rs.moveToInserRow();
rs.updateString("Password", strNewPass);
rs.updateString("Password", strConfPass);
if(strNewPass.equals(strConfPass))
{
JOptionPane.showMessageDialog(this, "Password change successfuly");
}
else
{JOptionPane.showMessageDialog(this, "Password do not match");
}
}
else
{
JOptionPane.showMessageDialog(this, "Wrong old Password");
}
}
catch(SQLException ex)
{
ex.printStackTrace();
}
}
this code is to be performed when a submit button is clicked.
i have this error : Exception occurred during event dispatching: jana.lang.NullPointerException.
please help me out with this code that will allow users to change their old password to a new one in the database created by correcting my error
Thanx
Use this code..its written by me
private void btnChangePasswordActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
// TODO add your handling code here:
String Newpass=String.valueOf(txtNewPassword.getPassword());
String ConfPass=String.valueOf(txtConfirmPassword.getPassword());
String OldPass=String.valueOf(txtOldPassword.getPassword());
String uName=txtUsername.getText();
if (uName.equals("")) {
JOptionPane.showMessageDialog( this, "Please enter a username",
"Error", JOptionPane.ERROR_MESSAGE);
return;
} else if (OldPass.equals("")) {
JOptionPane.showMessageDialog( this, "Please enter a old password",
"Error", JOptionPane.ERROR_MESSAGE);
return;
} else if (Newpass.equals("")) {
JOptionPane.showMessageDialog( this, "Please enter a new password",
"Error", JOptionPane.ERROR_MESSAGE);
return;
} else if (ConfPass.equals("")) {
JOptionPane.showMessageDialog( this, "Please enter a confirmed password",
"Error", JOptionPane.ERROR_MESSAGE);
return;
}
else if (Newpass.length() 5) {
JOptionPane.showMessageDialog(this,
"The New Password Should be of Atleast 5 Characters",
"Error", JOptionPane.ERROR_MESSAGE);
return;
}
else if ((Newpass).equals(OldPass)) {
JOptionPane.showMessageDialog(this,
"Password is same..Re-enter new password","Error", JOptionPane.ERROR_MESSAGE);
return;
}
else if (!(Newpass).equals(ConfPass)) {
JOptionPane.showMessageDialog(this,
"New Password doesn't match with Confirmed Password",
"Error", JOptionPane.ERROR_MESSAGE);
return;
}
try{
con=Connect.ConnectDB();
String sql= "select username,user_password from users";
pst=con.prepareStatement(sql);
rs= pst.executeQuery();
while(rs.next())
{
String usrname = rs.getString("username").trim();
String passwd = rs.getString("user_password").trim();
if(uName.equals(usrname) && OldPass.equals(passwd))
{
con=Connect.ConnectDB();
String sql1= "update users set User_password= '" + Newpass + "' where Username= '" + uName + "' and User_password = '" + OldPass + "'";
Statement stmt = con.createStatement();
stmt.execute(sql1.toString());
stmt.close();
JOptionPane.showMessageDialog(this,"Password Successfully Changed");
txtUsername.setText("");
txtOldPassword.setText("");
txtNewPassword.setText("");
txtConfirmPassword.setText("");
Login frm = new Login();
this.hide();
frm.setVisible(true);
}
else
{
JOptionPane.showMessageDialog(this,"invalid user name or password","Error", JOptionPane.ERROR_MESSAGE);
txtUsername.setText("");
txtOldPassword.setText("");
txtNewPassword.setText("");
txtConfirmPassword.setText("");
}
}
}catch(Exception ex){
JOptionPane.showMessageDialog(this,ex);
}
}