记录存在问题+文本字段标准

Question

Basically, a have a sign-up interface THAT should empty fileds and certain conditions and if record exist in data basewhere first it checks if text fields are empty as written below :

 private void confirmActionPerformed(java.awt.event.ActionEvent evt) {                                        
            //  String f= "jdbc:derby://localhost:1527/BStest";
     String name=username.getText();
            String gender=null;
            String passw=String.valueOf(pass.getPassword());
             String repassw=String.valueOf(repass.getPassword());
            String phone2=phone.getText();
            String emaill=email.getText();
            boolean checkage=false,checknum=false,checkcap=false,checklaw=false,checkemail=false,checkdomain=false;
            boolean checklen=false,checkbfat=false,checkpass=false,checkchar=false,checkgender=false;
                boolean    checkempty=true;

              if(name.isEmpty()){//is text field empty 
              checkempty=false;
              JOptionPane.showMessageDialog(null,"Add a username!");}
          if(passw.isEmpty()){//is text field empty 
              checkempty=false;
              JOptionPane.showMessageDialog(null,"Add a Password!");}
           if(!repassw.equals(passw)){//confirmed password is the same for password
               checkempty=false;
               JOptionPane.showMessageDialog(null,"Type password Again!");
           }
           if(phone2.isEmpty()){//is text field empty 
               checkempty=false;
               JOptionPane.showMessageDialog(null,"Add Phone number !");
           }
           if(emaill.isEmpty()){//is text field empty 
               checkempty=false;
               JOptionPane.showMessageDialog(null,"Add email please !");
           }

           if (!m.isSelected()&& !female.isSelected()){//no gender selected
               checkempty=false;
               JOptionPane.showMessageDialog(null,"Choose a gender !!");}
          else if (m.isSelected()&& female.isSelected()){//both selected it shoud be only one
              checkempty=false;
               JOptionPane.showMessageDialog(null,"Select only  One !!");}
          if(age.getText().isEmpty()){//is age text field has no input
             checkempty=false;
            JOptionPane.showMessageDialog(null,"Enter your age !!");}

Secondly checks the criteria for each text field as indicated in the comments below

if (m.isSelected()){// is female or male selected
               checkgender=true;
                 gender="Male";
             }
           else if (female.isSelected()){
               checkgender=true;
                 gender="Female";
             }
            int agee =Integer.parseInt(age.getText());      
            char c,c2=emaill.charAt(0);
            String zereofive=phone2.substring(0, 2);//start with 05
         String bfat = emaill.substring(0,emaill .indexOf("@"));//digits berfore @
String domain = emaill.substring(emaill .indexOf("@") + 1);//check domain
       if(Character.isLetter(c2))//is first char off email iis letter
            checkchar=true;
           else
           JOptionPane.showMessageDialog(null,"Emails only start with letters");


     if (phone2.length()==10 &&  zereofive.equals("05"))//check length of phone number 
          checklen=true;
        else
          JOptionPane.showMessageDialog(null,"enter 10 digits for the phone number and starts with 05");
if(bfat.length()>=6 || bfat.length()<=15){//check digits before @
   checkemail=true;
}
   if(domain.equals("gmail.com") || domain.equals("hotmail.com")){//check domain of email 
       checkdomain=true;
   }
       else
    JOptionPane.showMessageDialog(null,"Email domain is wrong");
   if(agee>=18)//only can register in 18 or above
                checkage=true;
          else
              JOptionPane.showMessageDialog(null,"You can't register because you are under 18. ");

    if(passw.length()>7){// password at least 8 digit  at least one captial and one small letter
           checklen=true;
          for (int i=0;i<passw.length();i++){
              c=passw.charAt(i);
          if(Character.isDigit(c))
          checknum=true;
          else if (Character.isUpperCase(c))
              checkcap=true;
          else if (Character.isLowerCase(c))
              checklaw=true;
          if(checknum && checkcap && checklaw )
              checkpass=true;

          }}
    if(checkpass)//check of all 3 crietria of pass word is coorrect 
        checkpass=true;
          else
            JOptionPane.showMessageDialog(null,"password must be at least 8 digits \n at least 1 Upper Case letter \n at least 1 Lower Case letter \n at least 1 number \n");

and lastly stores in the database if criteria is meet and record is not exists

    PreparedStatement reg,exist;
           String query="INSERT INTO customer (Cu_name, Cu_password, Cu_age, Cu_gender, Cu_email, Cu_phone) VALUES (?, ?, ?, ?, ?, ?)";//enter user info in database
           String record_exists="SELECT * FROM customer where Cu_name=? and Cu_password= ? and Cu_age=? and Cu_gender=? and Cu_email=? and Cu_phone=?";
           try{
               String f= "jdbc:derby://localhost:1527/BStest";
                Connection connection = DriverManager.getConnection(
            f, "meme", "Moudhi102"); 
          reg=connection.prepareStatement(query);
          exist=connection.prepareStatement(record_exists);
          reg.setString(1, name);
           reg.setString(2, passw);
             reg.setInt(3, agee);     
              reg.setString(4, gender);
               reg.setString(5, emaill);
                reg.setString(6, phone2);
                 exist.setString(1, name);
           exist.setString(2, passw);
             exist.setInt(3, agee);     
              exist.setString(4, gender);
               exist.setString(5, emaill);
                exist.setString(6, phone2);
                rs=exist.executeQuery();

                if(rs==null){            
       if(checkpass &&checkage && !checkdomain &&  !checkemail && !checklen && checkchar && !checkgender && checkempty    ){//if all criteria justified then add it to database

                   reg.executeUpdate();
                    JOptionPane.showMessageDialog(null,"Complete! new user added !! "); 

    }

        }else//else it can't be added
   {
       JOptionPane.showMessageDialog(null, "Record already exists");
    }
           }
           catch(SQLException ex){
            JOptionPane.showMessageDialog(null,ex);
        }

the problem is it doesn't show a message if record already exists in database and if I entered empty text in age + phone + email it shows the message that it is empty but in the NetBeans itself shows an error message in the output area like below at

java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:592)
    at java.lang.Integer.parseInt(Integer.java:615)
    at event_system.Sign_up.confirmActionPerformed(Sign_up.java:275)
    at event_system.Sign_up.access$000(Sign_up.java:20)
    at event_system.Sign_up$1.actionPerformed(Sign_up.java:70)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)

and doesn't do the coding part of these three fields and show their messages even for password if criteria is not meet and other field inputs are ok is shows a continuous message of record exists and Can't register check/fill you information.Please help me i'm stuck and can't figure it out

Answer 1

Deal with your exception first before even considereing to deal with your other problems since it will prevent the other portions of your code to be run from the point of exception and therefore be the root cause to all your problems at this time.

You can not pass a Null String ("") to the Integer#parseInt() method:

int agee = Integer.parseInt(age.getText());

If the Text Field that is to contain an age is empty then the JTextField#getText() method will return a Null String (""). If you supply this to the Integer#parseInt() method (as you've done in the above code) or anything other than an integer value then a NumberFormatException is generated. You need to take care of this possible condition and the use of a Ternary Operator (aka Conditional Operator) may be all you need:

int agee = age.getText().trim().equals("") ? 0 : Integer.parseInt(age.getText().trim());

This however doesn't cover the fact that a alpha character might accidently be supplied within the Age text field. To cover that problem it may be just better to do:

String theAge = age.trim().getText();
int agee = 0;
// Regular Expression used to ensure a Integer 
// Numerical String value was supplied.
if (theAge.matches("\\d+")) {
    agee = Integer.parseInt(theAge);
}

In the above line of code, IF the Age text-field contains nothing or blank spaces then the agee variable is supplied a integer 0 value ELSE the Integer.parseInt() method is used with the contents of the Text Field to fill the agee variable.

On a side note:

You utilize a lot of boolean flags for each of your text fields so as to ensure validity and other things. From what I can see you actually don't need any of them since you are checking all fields and your requirements are that all those fields actually be filled:

boolean checkage=false, checknum=false, checkcap=false, checklaw=false, 
        checkemail=false,checkdomain=false;
boolean checklen=false, checkbfat=false, checkpass=false, checkchar=false, 
        checkgender=false;
boolean checkempty=true;

I would get rid of all of them and and not use a flag at all. If at any time within your code any one of your Text Fields does not meet validity within the confirmActionPerformed() event then nothing should be read from or written to the database. As the fields are checked for validity and any of those fields fail you simply need to display the fact via Message Box then when the User selects the OK button we set focus on the Text Field currently being checked ( age.requestFocus(); ) then exit the event with a return; statement. Database code can never be reached unless all your text fields passes validity. Your event code might look like this:

private void confirmActionPerformed(java.awt.event.ActionEvent evt) {
    //  String f= "jdbc:derby://localhost:1527/BStest";
    String name = username.getText().trim();
    String gender = null;
    String passw = String.valueOf(pass.getPassword());
    String repassw = String.valueOf(repass.getPassword());
    String phone2 = phone.getText().trim();
    String emaill = email.getText().trim();

    // NAME
    //is Name text field empty 
    if (name.isEmpty()) {
        JOptionPane.showMessageDialog(null, "Add a username!");
        username.requestFocus();
        return;
    }

    // PASSWORD
    //is Password field empty 
    if (passw.isEmpty()) {
        JOptionPane.showMessageDialog(null, "Add a Password!");
        pass.requestFocus();
        return;
    }
    /* A Regular Expression is used here to ensure your desired
       password rules apply - Minimum of 8 characters in length,
       at least 1 Uppercase Letter, at least 1 Lowercase letter, 
       at least 1 digit.   */
    if (!passw.matches("^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)[a-zA-Z\\d]{8,}$")) {
        JOptionPane.showMessageDialog(null, "Password must be:\n\n"
                + "- At least 8 characters in length,\n"
                + "- Contain at least 1 Uppercase letter,\n"
                + "- Contain at least 1 Lowercase letter,\n"
                + "- Contain at least 1 number.");
        pass.requestFocus();
        return;
    }
    // confirmed password is the same for password
    if (!repassw.equals(passw)) {
        JOptionPane.showMessageDialog(null, "Type password Again!");
        repass.requestFocus();
        return;
    }

    // PHONE
    //is phone text field empty 
    if (phone2.isEmpty()) {//is text field empty 
        JOptionPane.showMessageDialog(null, "Add Phone number !");
        phone.requestFocus();
        return;
    }
    // starts with 05
    String zereofive = phone2.substring(0, 2);
    // check length of phone number 
    if (phone2.length() != 10 && !zereofive.equals("05")) {
        JOptionPane.showMessageDialog(null, "enter 10 digits for the phone number and starts with 05");
        phone.requestFocus();
        return;
    }

    // E-MAIL
    //is E-Mail text field empty
    if (emaill.isEmpty()) {
        JOptionPane.showMessageDialog(null, "Add email please !");
        email.requestFocus();
        return;
    }
    // E-Mail
    char c, c2 = emaill.charAt(0);
    String bfat = emaill.substring(0, emaill.indexOf("@"));//digits berfore @
    String domain = emaill.substring(emaill.indexOf("@") + 1);//check domain
    // is first char off email a letter
    if (!Character.isLetter(c2)) {
        JOptionPane.showMessageDialog(null, "Emails can only start with letters!");
        email.requestFocus();
        return;
    }
    //check digits before @
    if (bfat.length() < 6 || bfat.length() > 15) {
        JOptionPane.showMessageDialog(null, "Invalid digits in Email address!");
        email.requestFocus();
        return;
    }
    //check domain of email
    if (!domain.equals("gmail.com") && !domain.equals("hotmail.com")) {
        JOptionPane.showMessageDialog(null, "Email domain is wrong!");
        email.requestFocus();
        return;
    }

    // GENDER
    //no gender selected
    if (!m.isSelected() && !female.isSelected()) {
        JOptionPane.showMessageDialog(null, "Choose a Gender!!");
        return;
    }
    //both Genders are selected where it shoud be only one
    else if (m.isSelected() && female.isSelected()) {
        JOptionPane.showMessageDialog(null, "Select only One Gender!!");
        return;
    }
    // is female or male selected
    if (m.isSelected()) {
        gender = "Male";
    }
    else if (female.isSelected()) {
        gender = "Female";
    }

    // AGE
    //is Age text field empty
    String theAge = age.trim().getText();
    if (theAge.isEmpty()) {
        JOptionPane.showMessageDialog(null, "Enter your age !!");
        age.requestFocus();
        return;
    }
    int agee = 0;    // Default
    // Regular Expression used to ensure a Integer 
    // Numerical String value was supplied.
    if (theAge.matches("\\d+")) {
        agee = Integer.parseInt(theAge);
    }
    // only 18 + can register
    if (agee < 18) {
        JOptionPane.showMessageDialog(null, "You can't register because you are under 18!");
        age.requestFocus();
        return;
    }

    // DATABASE
    Connection connection = null;
    PreparedStatement reg, exist;
    ResultSet rs = null;
    String query = "INSERT INTO customer (Cu_name, Cu_password, Cu_age, Cu_gender, Cu_email, Cu_phone) VALUES (?, ?, ?, ?, ?, ?)";//enter user info in database
    String record_exists = "SELECT * FROM customer where Cu_name=? and Cu_password= ? and Cu_age=? and Cu_gender=? and Cu_email=? and Cu_phone=?";
    try {
        String f = "jdbc:derby://localhost:1527/BStest";
        connection = DriverManager.getConnection(f, "meme", "Moudhi102");
        reg = connection.prepareStatement(query);
        exist = connection.prepareStatement(record_exists);
        reg.setString(1, name);
        reg.setString(2, passw);
        reg.setInt(3, agee);
        reg.setString(4, gender);
        reg.setString(5, emaill);
        reg.setString(6, phone2);

        exist.setString(1, name);
        exist.setString(2, passw);
        exist.setInt(3, agee);
        exist.setString(4, gender);
        exist.setString(5, emaill);
        exist.setString(6, phone2);
        rs = exist.executeQuery();

        if (rs == null) {
            reg.executeUpdate();
            JOptionPane.showMessageDialog(null, "Complete! new user added !! ");
        }
        // User Already Exists In Database
        else {
            JOptionPane.showMessageDialog(null, "User already exists");
        }
    }
    catch (SQLException ex) {
        JOptionPane.showMessageDialog(null, ex);
    }
    finally {
        if (reg != null) {
            reg.close();
        }
        if (rs != null) {
            rs.close();
        }
        if (connection != null) {
            connection.close();
        }
    }

}

Age may not necessarily be a good piece of criteria to use in your query WHERE clause when checking database records for a duplicate record of a particular User. It only enforces the fact that each record is only valid for a single year. Things change and Age, E-Mails, Phone Numbers, etc are some of those things that can change often. There is obviously nothing wrong with the concept if only the Name and Password are used for access validity (which should suffice for most cases) and the remaining criteria is merely used for indicating that updating is required to the User data account.

You should consider Supplied Passwords to be hashed and it is the hash that is stored in database. When a User supplies a password then that password is hashed and compared to a hash already stored in database. No one, including yourself should ever know what the password truly is. Only the User should ever know what the password might be. jBCrypt works pretty good for this. To hash a password using this library:

Imports:

import org.mindrot.jbcrypt.BCrypt;
import static org.mindrot.jbcrypt.BCrypt.hashpw;

A Class Member Varaible:

// Define the BCrypt WORKLOAD to use when generating
// password hashes. 10-31 is a valid value.
private static final int WORKLOAD = 12;

To Hash a plaintext password so as to store in database:

/**
 * This method can be used to generate a string representing an account
 * password suitable for storing in a database. It will be an OpenBSD-style
 * crypt(3) formatted hash string of length=60 The BCrypt WORKLOAD is
 * specified in the above static variable, a value from 10 to 31. A WORKLOAD
 * of 12 is a very reasonably safe default. This automatically handles
 * secure 128-bit salt generation and storage within the hash.
 *
 * @param password_plaintext The account's plaintext password as provided
 *                           during account creation, or when changing an
 *                           account's password.
 *
 * @return String - a string of length 60 that is the bcrypt hashed password
 *         in crypt(3) format.
 */
public static String hashPassword(String password_plaintext) {
    String salt = BCrypt.gensalt(WORKLOAD);
    String hashedPassword = hashpw(password_plaintext, salt);
    return hashedPassword;
}

To check a plaintext password with a stored hash from database:

/**
 * This method can be used to verify a computed hash from a plaintext (e.g.
 * during a login request) with that of a stored hash from a database. The
 * password hash from the database must be passed as the second argument.
 *
 * @param passwordAsPlainText The accounts plaintext password, as provided
 *                            during a login request
 *
 * @param storedEncryption    The accounts stored password hash, retrieved
 *                            from the authorization database
 *
 * @return boolean - true if the password matches the password of the stored
 *         hash, false otherwise
 */
/*
public static boolean checkPassword(String passwordAsPlainText, String storedEncryption) {
    boolean passwordVerification;

    if (null == storedEncryption || !storedEncryption.startsWith("$2a$")) {
        throw new java.lang.IllegalArgumentException(
                "Invalid encryption provided for comparison");
    }

    passwordVerification = checkpw(passwordAsPlainText, storedEncryption);

    return passwordVerification;
}