Validation.java

import java.util.regex.*;
/**
 * Write a description of class Validation here.
 *
 * @author (your name)
 * @version (a version number or a date)
 */
public class Validation
{
    /**
     * A default constructor for objects of class Validation
     */
    public Validation()
    {
    }

    /**
     * Create a validateAmount method to validate Amount.
     */
    public boolean validateAmount(String amount)
    {
        amount = amount.trim();
        if (amount.length() == 0)
        {
            System.out.println("No amount was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (amount.matches("^[0-9]+$") || amount.matches("^[0-9]+.[0-9]*$"))
        {
            if (Double.valueOf(amount) > 0)
                return true;
            else
            {
                System.out.println("Amount should be a number larger than 0. Please try again(Enter \"X\" to cancel):");
                return false;
            }
        }
        else
        {
            System.out.println("Amount should be a number larger than 0. Please try again(Enter \"X\" to cancel):");
            return false;
        }
    }

    /**
     * Create a validateInteger method to check whether the inputted value is an integer.
     */
    public boolean validateInteger(String value)
    {
        value = value.trim();
        if (value.matches("^[1-9]+[0-9]*$") || value.equals("x"))
            return true;
        else
        {
            System.out.println("You can only input digits! Please try again");
            return false;
        }
    }
    
    /**
     * Create a validatePassword method to validate Password.
     */
    public boolean validatePassword(String password)
    {
        password = password.trim();
        if (password.length() < 8 || password.length() > 20)
        {           
            System.out.println("The length of password should be between 8 to 20. Please try again(Enter \"X\" to cancel):"); 
            return false;
        }
        int index = 0;
        if (password.matches(".*[a-z]{1,}.*"))
            index++;
        else
        {           
            System.out.println("There should be at least one lowercase in the password. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        if (password.matches(".*[A-Z]{1,}.*"))
            index++;
        else
        {         
            System.out.println("There should be at least one uppercase in the password. Please try again(Enter \"X\" to cancel):");
            return false;
        }

        if (password.matches(".*\\d{1,}.*"))
            index++;
        else
        {          
            System.out.println("There should be at least one digit in the password. Please try again(Enter \"X\" to cancel):");
            return false;
        }

        if (password.matches(".*[_\\W]{1,}.*"))
            index++;
        else
        {           
            System.out.println("There should be at least one special character in the password. Please try again(Enter \"X\" to cancel):");             
            return false;
        }

        if (index == 4)
            return true;
        else
        {    
            System.out.println("There should be at least one special character, one digit, one uppercase and one lowercase in the password. Please try again(Enter \"X\" to cancel):");
            return false;             
        }
    }
    
    /**
     * Create a validateProductAmount method to validate product amount.
     */
    public boolean validateProductAmount(String amount)
    {
        if (amount.length() == 0)
        {
            System.out.println("No amount was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (amount.matches("^[0-9]+$") || amount.matches("^[0-9]*\\.[0-9]*$"))
        {
            if (Double.valueOf(amount) > 0)
                return true;
            else
            {
                System.out.println("Amount should be a number larger than 0. Please try again(Enter \"X\" to cancel):");
                return false;
            }
        }
        else
        {
            System.out.println("Amount should be a number larger than 0. Please try again(Enter \"X\" to cancel):");
            return false;
        }
    }
    
    /**
     * Create a validateProductCategory method to validate Product Category.
     */
    public boolean validateProductCategory(String category)
    {
        category = category.trim();
        if(category.toLowerCase().equals("fruit") || category.toLowerCase().equals("vegetable"))
            return true;
        else
        {
            System.out.println("Please enter fruit or vegetable(Enter \"X\" to cancel):");
            return false;
        }
    }
    
    /**
     * Create a validateProductDiscount method to validate product Discount.
     */
    public boolean validateProductDiscount(String productDiscount)
    {
        int a = 0;
        productDiscount = productDiscount.trim();
        if (productDiscount.length() == 0)
        {   
            System.out.println("No discount was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        for (int i=0; i < productDiscount.length(); i++)
        {
            if(!Character.isDigit(productDiscount.charAt(i)))
            {
                if((productDiscount.charAt(i)) != ('.'))
                {
                    System.out.println("Please input a valid product discount in digits(Enter \"X\" to cancel):"); 
                    return false;
                }
                else if ((productDiscount.charAt(i)) == ('.'))
                    a++;
            }
        }
        if (a > 1)
        {
            System.out.println("There should be only one decimal point. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        double d = Double.parseDouble(productDiscount);
        if (d <= 0 || d > 1)
        {   
            System.out.println("Please input a valid product discount which is between 0(exclude) to 1(include)(Enter \"X\" to cancel):"); 
            return false;
        }
        else
            return true;
    }
    
    /**
     * Create a validateProductName method to validate Product Name.
     */
    public boolean validateProductName(String productName)
    {
        productName = productName.trim();
        if(productName.length() == 0)
        {
            System.out.println("No product name was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (productName.length() >= 15)
        {
            System.out.println("The length of product name should between 1 to 15. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (productName.matches(".*[a-zA-Z]{2,}.*") == false)
        {
            System.out.println("There should be at least two adjacent letters in product name. Please try again(Enter \"X\" to cancel):");
            return false;
        }

        return true;
    }
    
    /**
     * Create a validateProductOrigin method to validate product Origin.
     */
    public boolean validateProductOrigin(String productOrigin)
    {
        productOrigin = productOrigin.trim();
        if (productOrigin.length() < 2 ||
        productOrigin.length() > 20)
        {          
            System.out.println("The length of product origin should be between 2 to 20. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (productOrigin.matches(".*[a-zA-Z]{2,}.*")==false)
        {        
            System.out.println("There should be at least two adjacent letters in the product origin. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else
            return true;
    }
    
    /**
     * Create a validateProductPrice method to validate Product Price.
     */
    public boolean validateProductPrice(String price)
    {
        price = price.trim();
        if (price.length() == 0)
        {
            System.out.println("No price was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (price.matches("^[0-9]+$") || price.matches("^[0-9]+.[0-9]*$"))
        {
            if (Double.valueOf(price) > 0)
                return true;
            else
            {
                System.out.println("Price should be a number larger than 0. Please try again(Enter \"X\" to cancel):");
                return false;
            }
        }
        else
        {
            System.out.println("Price should be a number larger than 0. Please try again(Enter \"X\" to cancel):");
            return false;
        }
    }
    
    /**
     * Create a validateProductShelfLife method to validate product Shelf Life.
     */
    public boolean validateProductShelfLife(String productShelfLife)
    {
        productShelfLife = productShelfLife.trim();
        if (productShelfLife.length() == 0)
        {
            System.out.println("No shelf life was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        for (int i = 0; i < productShelfLife.length(); i++)
        {
            if (!Character.isDigit(productShelfLife.charAt(i)))
            {
                System.out.println("Please input a valid product shelf life in digits(Enter \"X\" to cancel):"); 
                return false;
            }
            else 
                return true;
        }
        int i = Integer.parseInt(productShelfLife);        
        if (i <= 0 )
        {   
            System.out.println("Please input a valid product shelf life which is higer than 0(Enter \"X\" to cancel):"); 
            return false;
        }
        else
            return true;
    }
    
    /**
     * Create a validateUserAddress method to validate User Address.
     */
    public boolean validateUserAddress(String address)
    {
        address = address.trim();
        if(address.length() == 0)
        {
            System.out.println("No address was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (address.length() >= 50)
        {
            System.out.println("The length of address should less than 50. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (address.matches(".*[a-zA-Z]{2,}.*") == false)
        {
            System.out.println("There should be at least two adjacent letters in address. Please try again(Enter \"X\" to cancel):");

            return false;
        }
        return true;
    }
    
    /**
     * Create a validateUserEmail method to validate User Email.
     */
    public boolean validateUserEmail(String email)
    {
        email = email.trim();
        if (email.length() == 0)
        {
            System.out.println("No email was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        String regex = "^([a-z0-9A-Z]+[-|\\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\\.)+[a-zA-Z]{2,}$";
        Pattern p = Pattern.compile(regex);
        Matcher m = p.matcher(email);
        if (!m.matches())
        {
            System.out.println("Please enter the correct email format(Example: someone@somesite.com)(Enter \"X\" to cancel):");
            return false;
        }
        return true;   
    }
    
    /**
     * Create a validateUserName method to validate User Name.
     */
    public boolean validateUserName(String userName)
    {
        int hyphenNumber = 0;//The number of hyphen in the player name.
        int alphabetNumber = 0;//The number of alphabet in the player name.
        for (int i = 0;i < userName.length();i++)
        {
            if (userName.toUpperCase().charAt(i) >= 'A' && userName.toUpperCase().charAt(i) <= 'Z')       
                alphabetNumber++;

            if (userName.charAt(i) == '-')
                hyphenNumber++;
        }           
        if (alphabetNumber + hyphenNumber != userName.length())
        {
            System.out.println("Error!Player name can contain only alphabetical characters and hyphen. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        if (alphabetNumber < 2)
        {
            System.out.println("Error!At least two alphabetical characters should be used. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        if (alphabetNumber + hyphenNumber > 20)
        {
            System.out.println("Error!Name length can't be longer than 20. Please try again(Enter \"X\" to cancel):");
            return false;            
        }
        if (hyphenNumber > 1 || userName.charAt(0) == '-' || userName.charAt(userName.length() - 1) == '-')
        {
            System.out.println("Error!Hyphen can't be at begin or end of the name!At most one hyphen can be used. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        return true;   
    }
    
    /**
     * Create a validateUserPhone method to validate User Phone.
     */
    public boolean validateUserPhone(String phone)
    {
        phone = phone.trim();
        if (phone.length() == 0)
        {
            System.out.println("No phone was entered. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (phone.length() >= 20)
        {
            System.out.println("The length of phone should less than 20. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if(phone.replaceAll("[_\\W]","").length() != phone.length())
        {
            System.out.println("The phone number cannot contain special characters. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        else if (phone.matches(".*[a-zA-Z]{1,}.*"))
        {
            System.out.println("The phone number cannot contain letters. Please try again(Enter \"X\" to cancel):");
            return false;
        }
        return true;
    }
    
    /**
     * Create a validateYN method to validate input choice (yes or no).
     */
    public boolean validateYN(String option)
    {
        option = option.toUpperCase().trim();
        if (option.equals("Y") || option.equals("N"))
            return true;
        else
        {
            System.out.println("You can only choose \"y\" or \"n\". Please try again:");
            return false;
        }
    }
}