Operation
· When the application starts, it displays the Index page. This page contains a link that leads to the Products page that can be used to view and add products.
· To add a new product, the user selects the Add Product button. This displays the Product page with all text fields empty. Then, the user can fill in the text fields and click on the Update Product button to add the product.
Specifications
· Use a Product class like the one shown later in this document to store the product data.
· Use a ProductIO class like the one shown later in this document to read the product data from a text file named products.txt in the WEB-INF directory.
· Use a text file like the products.txt file shown later in this document as a starting point for the products that are available to the application.
· Use server-side validation to validate all user entries. In particular, make sure the user enters a code, description, and price for each product. In addition, make sure the product's price is a valid double value.
· Get the Product.java, ProductIO.java, and product.txt files from your instructor. The files are also provided below:
The Product class
package books;
import java.text.NumberFormat;
import java.io.Serializable;
public class Product implements Serializable
{
private String code;
private String description;
private double price;
public Product()
{
code = "";
description = "";
price = 0;
}
public void setCode(String code)
{
this.code = code;
}
public String getCode()
{
return code;
}
public void setDescription(String description)
{
this.description = description;
}
public String getDescription()
{
return description;
}
public void setPrice(double price)
{
this.price = price;
}
public double getPrice()
{
return price;
}
public String getPriceNumberFormat()
{
NumberFormat number = NumberFormat.getNumberInstance();
number.setMinimumFractionDigits(2);
if (price == 0)
return "";
else
return number.format(price);
}
public String getPriceCurrencyFormat()
{
NumberFormat currency = NumberFormat.getCurrencyInstance();
return currency.format(price);
}
}
The ProductIO class
package books;
import java.io.*;
import java.util.*;
public class ProductIO
{
private static ArrayList products = null;
public static ArrayList getProducts(String path)
{
products = new ArrayList();
File file = new File(path);
try
{
BufferedReader in =
new BufferedReader(
new FileReader(file));
String line = in.readLine();
while (line != null)
{
StringTokenizer t = new StringTokenizer(line, "|");
if (t.countTokens() >= 3)
{
String code = t.nextToken();
String description = t.nextToken();
String priceAsString = t.nextToken();
double price = Double.parseDouble(priceAsString);
Product p = new Product();
p.setCode(code);
p.setDescription(description);
p.setPrice(price);
products.add(p);
}
line = in.readLine();
}
in.close();
return products;
}
catch(IOException e)
{
e.printStackTrace();
return null;
}
}
public static Product getProduct(String productCode, String path)
{
products = getProducts(path);
for (Product p : products)
{
if (productCode != null &&
productCode.equalsIgnoreCase(p.getCode()))
{
return p;
}
}
return null;
}
public static boolean exists(String productCode, String path)
{
products = getProducts(path);
for (Product p : products)
{
if (productCode != null &&
productCode.equalsIgnoreCase(p.getCode()))
{
return true;
}
}
return false;
}
private static void saveProducts(ArrayList products,
String path)
{
try
{
File file = new File(path);
PrintWriter out =
new PrintWriter(
new FileWriter(file));
for (Product p : products)
{
out.println(p.getCode() + "|"
+ p.getDescription() + "|"
+ p.getPrice());
}
out.close();
}
catch(IOException e)
{
e.printStackTrace();
}
}
public static void insert(Product product, String path)
{
products = getProducts(path);
products.add(product);
saveProducts(products, path);
}
public static void update(Product product, String path)
{
products = getProducts(path);
for (int i = 0; i < products.size(); i++)
{
Product p = products.get(i);
if (product.getCode() != null &&
product.getCode().equalsIgnoreCase(p.getCode()))
{
products.set(i, product);
}
}
saveProducts(products, path);
}
public static void delete(Product product, String path)
{
products = getProducts(path);
for (int i = 0; i < products.size(); i++)
{
Product p = products.get(i);
if (product != null &&
product.getCode().equalsIgnoreCase(p.getCode()))
{
products.remove(i);
}
}
saveProducts(products, path);
}
}
A product.txt file that contains four products
J601|The Complete Geek's Guide to Java|34.95
CP01|C++ for Nerds|42.95
CP02|Advanced C++ for Nerds|37.95
C001|Old School Progamming Using ‘C'|14.95