用户模块
要登陆后才能购买，因此我们先写购买模块.
设计实体
private String id;
private String username;
private String password;
private String email;
private String cellphone;
private String address;
//各种setter、getter
设计数据库表
CREATE TABLE user (
id VARCHAR(40) PRIMARY KEY,
username VARCHAR(20) NOT NULL,
cellphone VARCHAR(20) NOT NULL,
address VARCHAR(40) NOT NULL,
email VARCHAR(30),
password VARCHAR(30) NOT NULL
);
编写DAO
/**
* 用户的登录注册模块
* 1：登陆
* 2：注册
* 3：根据id查找具体的用户
*/
public class UserDaoImpl {
public void register(User user) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "INSERT INTO user (id,username,cellphone,address,email,password) VALUES(?,?,?,?,?,?)";
try {
queryRunner.update(sql, new Object[]{user.getId(),user.getUsername(), user.getCellphone(), user.getAddress(), user.getEmail(), user.getPassword()});
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
public User login(String username, String password) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT * FROM user WHERE username = ? AND password=?";
try {
return (User) queryRunner.query(sql, new Object[]{username, password}, new BeanHandler(User.class));
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
public User find(String id) {
QueryRunner queryRunner = new QueryRunner(Utils2DB.getDataSource());
String sql = "SELECT * FROM user WHERE id=?";
try {
return (User) queryRunner.query(sql, id, new BeanHandler(User.class));
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
测试DAO
public class UserDemo {
UserDaoImpl userDao = new UserDaoImpl();
@Test
public void add() {
User user = new User();
user.setId("1");
user.setUsername("zhong");
user.setPassword("123");
user.setCellphone("10085");
user.setAddress("广州萝岗");
user.setEmail("40368324234234@QQ.com");
userDao.register(user);
}
@Test
public void find() {
String id = "1";
User user = userDao.find(id);
System.out.println(user.getEmail());
}
@Test
public void login() {
String username = "zhong";
String password = "123";
User user = userDao.login(username, password);
System.out.println(user.getAddress());
}
}
抽取DAO
public interface UserDao {
void register(User user);
User login(String username, String password);
User find(String id);
}
编写Service
private UserDao userDao = DaoFactory.getInstance().createDao("zhongfucheng.dao.impl.UserDaoImpl", UserDao.class);
public void registerUser(User user) {
userDao.register(user);
}
public User loginUser(String username,String password) {
return userDao.login(username, password);
}
public User findUser(String id) {
return userDao.find(id);
}
前台样式
- head.jsp
<div id="User">
用户名：<input type="text" name="username">
密码：<input type="password" name="password">
<button name="login">登陆</button>
<button name="register">注册</button>
</div>
- head.css
#body {
position: relative;
}
#user {
position: absolute;
margin-top: 130px;
margin-left: 1364px;
}
- 效果：
实现登陆注册功能
当点击登陆按钮的时候，把数据带过去给Servlet，让Servlet调用BusinessService方法，实现登陆。注册同理.....因此，我们需要用到JavaScript代码
- head.jsp
<c:if test="${user==null}" >
<div id="User">
用户名：<input type="text" id="username">
密码：<input type="password" id="password">
<button name="login" onclick="login()">登陆</button>
<button name="register" onclick="register()">注册</button>
</div>
</c:if>
<c:if test="${user!=null}" >
<div id="User">
欢迎您：${user.username} <a href="${pageContext.request.contextPath}/UserServlet?method=Logout">注销</a>
</div>
</c:if>
- javaScript代码
<script type="text/javascript">
function login() {
//得到输入框的数据
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
//跳转到相对应的Servlet上
window.location.href = "${pageContext.request.contextPath}/UserServlet?method=login&username=" + username + "&password=" + password;
}
function register() {
//跳转到注册页面
window.location.href = "${pageContext.request.contextPath}/client/register.jsp";
}
</script>
- UserServlet
String method = request.getParameter("method");
BussinessServiceImpl service = new BussinessServiceImpl();
if (method.equals("login")) {
try {
//得到页面传递过来的数据
String username = request.getParameter("username");
String password = request.getParameter("password");
User user = service.loginUser(username, password);
request.getSession().setAttribute("user",user);
request.getRequestDispatcher("/client/head.jsp").forward(request, response);
} catch (Exception e) {
request.setAttribute("message", "登陆失败了！");
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
} else if (method.equals("register")) {
try {
//得到JSP传递过来的数据，封装成Bean对象
User user = WebUtils.request2Bean(request, User.class);
user.setId(WebUtils.makeId());
service.registerUser(user);
request.setAttribute("message", "注册成功了！");
} catch (Exception e) {
e.printStackTrace();
request.setAttribute("message", "注册失败了！");
}
request.getRequestDispatcher("/message.jsp").forward(request, response);
} else if (method.equals("Logout")) {
//销毁session
request.getSession().invalidate();
//回到首页
request.getRequestDispatcher("/client/head.jsp").forward(request, response);
}
购买模块
在显示图书的时候，顺便添加购买的超链接
<li><a href="#">购买</a></li>
设计购物车实体
如果不清楚为什么这样设计，可参考我之前的博文：http://blog.csdn.net/hon_3y/article/details/56481439#t5
- Cart实体
public class Cart {
private Map<String, CartItem> map = new HashMap<>();
private double price;
//提供把商品添加到购物的功能
public void addBook2Cart(Book book) {
//得到对应的购物项
CartItem cartItem = map.get(book.getId());
//如果是null，说明购物车还没有该购物项
if (cartItem == null) {
cartItem = new CartItem();
cartItem.setQuantity(1);
cartItem.setBook(book);
cartItem.setPrice(book.getPrice());
//把购物项加到购物车中
map.put(book.getId(), cartItem);
} else {
//如果购物车有该购物项了，那么将购物项的数量+1
cartItem.setQuantity(cartItem.getQuantity() + 1);
}
}
//购物车的价钱是购物项价钱的总和
public double getPrice() {
double totalPrice = 0;
for (Map.Entry<String, CartItem> me : map.entrySet()) {
CartItem cartItem = me.getValue();
totalPrice += cartItem.getPrice();
}
return totalPrice;
}
public Map<String, CartItem> getMap() {
return map;
}
public void setMap(Map<String, CartItem> map) {
this.map = map;
}
public void setPrice(double price) {
this.price = price;
}
}
设计购物项实体
public class CartItem {
private Book book;
private double price;
private int quantity;
public double getPrice() {
return this.book.getPrice() * this.quantity;
}
public void setPrice(double price) {
this.price = price;
}
public Book getBook() {
return book;
}
public void setBook(Book book) {
this.book = book;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
}
处理用户想要买的书籍Servlet
<li><a href="${pageContext.request
.contextPath}/BuyServlet?book_id=${book.id}">购买</a></li>
- BuyServlet
BussinessServiceImpl service = new BussinessServiceImpl();
//先检查该用户是否登陆了。
User user = (User) request.getSession().getAttribute("user");
if (user == null) {
request.setAttribute("message", "您还没登陆，请登陆了再来购买");
request.getRequestDispatcher("/message.jsp").forward(request, response);
return ;
}
//如果登陆了...
//得到该用户的购物车
Cart cart = (Cart) request.getSession().getAttribute("cart");
if (cart == null) {
cart = new Cart();
request.getSession().setAttribute("cart", cart);
}
//得到用户想买的书籍
String book_id = request.getParameter("book_id");
Book book = service.findBook(book_id);
//把书籍添加到购物车中
service.buyBook(cart, book);
request.setAttribute("message", "该商品已添加到购物车中");
request.getRequestDispatcher("/message.jsp").forward(request,response);