商店客户服务程序
老师上课演示了一个程序，让我们课下补完，过程中出现了一些问题，我java菜鸟一只，求~
Product.java:
id,name,description变量，以及对应的get和set函数
Store.java:
void addProduct(...){...}
void removeProduct(...){...}
void delProduct(...){...}
void printProductList(...){...}
Seller.java
Store store;
String sellerName;
BuyList.java:
public void addProduct(String name, int number){...}
Buyer.java:
BuyList buylist;
String buyerName;
Test.java:
测试的实现。
问题出现啦：main函数必然是static的，可是main引用的一些sellerRun（运行seller操作的函数）和buyerRun也必须设置为static，否则报错。
运行的时候选择seller之后设置完产品列表，返回到上一级菜单（选择buyer还是seller的菜单）的时候没法保存产品列表，无论再进哪个用户都会显示产品列表为空（这个问题和static有关么）
刚从c转过来，封装性和面向对象让人很头大，总感觉这程序开始构思的时候就有一些混乱……
[解决办法]
在网上找一本自己喜欢的讲java基础的书看吧！
这些都是java基础，还是需要自己慢慢练，慢慢理解的!
[解决办法]
/** ***************************************Seller*************************************************** */class Seller implements Comparable<Seller> { private int id; private ArrayList<Product> products; private Intermediary intermediary;// private Seller(int id) { this.id = id; init(); } private Seller(int id, ArrayList<Product> products, Intermediary intermediary) { this.id = id; this.products = products; this.intermediary = intermediary; init(); } private void init() { if (products == null) products = new ArrayList<Product>(); if (intermediary == null) intermediary = Intermediary.createIntermediary(0); } public static Seller createSeller(int id) { return new Seller(id); } public static Seller createSeller(int id, ArrayList<Product> products, Intermediary intermediary) { return new Seller(id, products, intermediary); } boolean add(Product product) {// new arrivals return products.add(product); } boolean remove(Product product) {// take out of return products.remove(product); } public Product getProduct(int id) {// display product for (int i = 0; i < products.size(); i++) { if (products.get(i).getId() == id) return products.get(i); } return null; } public void displayProductInStore() {// display product for (int i = 0; i < products.size(); i++) { System.out.println(products.get(i)); } } public int compareTo(Seller seller) { int temp = id > seller.id ? 1 : (id == seller.id ? 0 : -1); return temp; } public Intermediary getIntermediary() { return intermediary; } public void setIntermediary(Intermediary intermediary) { this.intermediary = intermediary; } public int getId() { return id; } public void setId(int id) { this.id = id; } public ArrayList<Product> getProducts() { return products; } public void setProducts(ArrayList<Product> products) { this.products = products; } public String toString() { return getClass().getSimpleName() + id; }}/** ***************************************Buyer*************************************************** */class Buyer implements Comparable<Buyer> { private int id; private ArrayList<Product> products; private Seller seller;// private Intermediary intermediary;// private Buyer(int id) { this.id = id; init(); } private Buyer(int id, ArrayList<Product> products, Seller seller, Intermediary intermediary) { super(); this.id = id; this.products = products; this.seller = seller; this.intermediary = intermediary; init(); } private void init() { if (products == null) products = new ArrayList<Product>(); if (seller == null) seller = Seller.createSeller(0); if (intermediary == null) intermediary = Intermediary.createIntermediary(0); } public static Buyer createBuyer(int id) { return new Buyer(id); } public static Buyer createBuyer(int id, ArrayList<Product> products, Seller seller, Intermediary intermediary) { return new Buyer(id, products, seller, intermediary); } public void add(int id, String name, String descreption) {// add products.add(Product.createProduct(id, name, descreption)); } public void add(Product product) {// add seller's product to shoppincar if (product != null) products.add(product); else throw new UnsupportedOperationException(); } public boolean remove(int id) {// remove product from shopping car for (int i = 0; i < products.size(); i++) { if (products.get(i).getId() == id) { products.remove(id); return true; } } return false; } boolean remove(Product product) {// remove product from shopping car return products.remove(product); } public Product getProduct(int id) { for (Product product : products) { if (product.getId() == id) return product; } return null; } public void displayProductInShoppingCar() {// display products in`shopping // car for (Product product : products) { System.out.println(product); } } public void displayProductFromSeller() { seller.displayProductInStore(); } public void displaySellerFromIntermediary() { intermediary.displaySeller(); } public void buy(Product product) {// buy thing intermediary.trade(seller, this, product); } public int compareTo(Buyer buyer) { int temp = id > buyer.id ? 1 : (id == buyer.id ? 0 : -1); return temp; } public int getId() { return id; } public void setId(int id) { this.id = id; } public Seller getSeller() { return seller; } public void setSeller(Seller seller) { this.seller = seller; } public Intermediary getIntermediary() { return intermediary; } public void setIntermediary(Intermediary intermediary) { this.intermediary = intermediary; } public ArrayList<Product> getProducts() { return products; } public void setProducts(ArrayList<Product> products) { this.products = products; } public String toString() { return getClass().getSimpleName() + id; }}/** ***************************************Product*************************************************** */class Product { private final int id;// 每件商品ID是唯一的 private String name; private String description; private Product(int id) { super(); this.id = id; init(); } private Product(int id, String name, String description) { super(); this.id = id; this.name = name; this.description = description; init(); } private void init() { if (name == null) name = "name" + id; if (description == null) description = "description" + id; } public static Product createProduct(int id) { return new Product(id); } public static Product createProduct(int id, String name, String description) { return new Product(id, name, description); } public int getId() { return id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public String toString() { return getClass().getSimpleName() + id; }}
[解决办法]
不一定非要用static方法的，调用方法用类的实例去调用也是一样的效果的
[解决办法]
一定非要用static方法