Question

I’m using Java Mail API:

PasswordAuthentication valid = new PasswordAuthentication(txtEmail.getText(), 
                                                         txtPassword.getText());

if (valid != null) {
    lblInvalid.setText("Correct information!");
} else {
    lblInvalid.setText("Invalid username or password!");
}

What I want it to do, I want the user to login with their gmail username and password. I want to check if that email username and password is the real gmail login information. How do I check if the email and password enters is the users gmail account.

Answer 1

To validate email address you can refer this link

http://www.mkyong.com/regular-expressions/how-to-validate-email-address-with-regular-expression/

For validating password: You just need to retrieve the stored password for a user from some database or other security frameworks and validate against the input done by the user.