catalog.java

来自「Enjoy Web Dev With Tapestry 一书的源代码」· Java 代码 · 共 36 行

package com.ttdev.shop;

import java.util.*;

public class Catalog {
	private List products;
	private static Catalog globalCatalog;

	public Catalog() {
		products = new ArrayList();
	}
	public List getProducts() {
		return products;
	}
	public void add(Product product) {
		products.add(product);
	}
	public static Catalog getGlobalCatalog() {
		if (globalCatalog == null) {
			globalCatalog = new Catalog();
			globalCatalog.add(new Product("p01", "Pencil", "a", 1.20));
			globalCatalog.add(new Product("p02", "Eraser", "b", 2.00));
			globalCatalog.add(new Product("p03", "Ball pen", "c", 3.50));
		}
		return globalCatalog;
	}
	public Product lookup(String productId) {
		for (Iterator iter = products.iterator(); iter.hasNext();) {
			Product product = (Product) iter.next();
			if (product.getId().equals(productId)) {
				return product;
			}
		}
		throw new IllegalArgumentException("Unknown product id: " + productId);
	}
}