Regular expressions

Email

String email= textField.getText();
            
//method implementation
private boolean validMail(String email) {
            Pattern emailPattern = Pattern.compile(".+@.+\\.[a-z]+");
            Matcher emailMatcher = emailPattern.matcher(email);
            return emailMatcher.matches();
        }

//method calling
if(validMail(email))
                    JOptionPane.showMessageDialog(rootPane, "email is right");
 else
                    JOptionPane.showMessageDialog(rootPane, "wrong email");


Password

String pw =textField_1.getText();
 
//method implementation
private boolean validPassword(String pw){
          
           Pattern passwPattern = Pattern.compile("[A-Za-z0-9]{0,6}");
            Matcher passwMatcher = passwPattern.matcher(pw);
            return passwMatcher.matches();
       }