2019上学期第十五周学习

1、登录处理类LoginServlet

net.wlq.shop.servlet;
/**
 * 功能：登录处理类
 * 作者：邓益春
 * 日期：2019年12月9日
 */

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import net.wlq.shop.bean.User;
import net.wlq.shop.service.UserService;

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 设置请求对象的字符编码
        request.setCharacterEncoding("utf-8");
        // 获取会话对象
        HttpSession session = request.getSession();
        // 获取用户名
        String username = request.getParameter("username");
        // 获取密码
        String password = request.getParameter("password");
        // 定义用户服务对象
        UserService userService = new UserService();
        // 执行登录方法，返回用户实体
        User user = userService.login(username, password);
        // 判断用户登录是否成功
        if (user != null) {
            // 设置session属性
            session.setMaxInactiveInterval(5 * 60);
            session.setAttribute("username", username);
            session.removeAttribute("loginMsg");
            // 根据用户权限跳转到不同页面
            if (user.getPopedom() == 0) {
                System.out.println("用户登陆成功，进入后台管理");
                response.sendRedirect(request.getContextPath() + "/backend/management.jsp");
            } else if (user.getPopedom() == 1) {
                System.out.println("用户登陆成功，进入前台显示类别");
                response.sendRedirect(request.getContextPath() + "/showCategory");
            }
        } else {
            System.out.println("用户名或密码错误，用户登陆失败");
            // 设置session属性loginMsg
            session.setAttribute("loginMsg", "用户名或密码错误！");
            response.sendRedirect(request.getContextPath() + "/login.jsp");
        }
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

LoginServlet进行测试：




2.注销处理类LogoutServlet

package net.wlq.shop.servlet;
/**
 * 功能：注销处理类
 * 作者：邓益春
 * 日期：2019年12月9日
 */

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/logout")
public class LogoutServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 让session失效
        request.getSession().invalidate();
        // 重定向到登录页面
        response.sendRedirect(request.getContextPath() + "/login.jsp");
        System.out.println("用户注销成功！");
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

先登陆成功后再注销

package net.wlq.shop.servlet;
/**
 * 功能：处理用户注册
 * 作者：邓益春
 * 日期：2019年12月9日
 */

import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLEncoder;
import java.sql.Timestamp;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import net.wlq.shop.bean.User;
import net.wlq.shop.service.UserService;

@WebServlet("/register")
public class RegisterServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 设置请求对象的字符编码
        request.setCharacterEncoding("utf-8");
        // 获取session对象
        HttpSession session = request.getSession();

        // 获取用户名
        String username = request.getParameter("username");
        // 获取密码
        String password = request.getParameter("password");
        // 获取电话号码
        String telephone = request.getParameter("telephone");
        // 设置注册时间（时间戳对象）
        Timestamp registerTime = new Timestamp(System.currentTimeMillis());
        // 设置用户为普通用户
        int popedom = 1;

        // 创建用户对象
        User user = new User();
        // 设置用户对象信息
        user.setUsername(username);
        user.setPassword(password);
        user.setTelephone(telephone);
        user.setRegisterTime(registerTime);
        user.setPopedom(popedom);

        // 创建UserService对象
        UserService userService = new UserService();
        // 调用UserService对象的注册方法
        int count = userService.addUser(user);

        // 判断是否注册成功
        if (count > 0) {
            // 设置session属性
            session.setAttribute("registerMsg", "恭喜，注册成功！");
            // 重定向到登录页面
            response.sendRedirect(request.getContextPath() + "/login.jsp");
            System.out.println("恭喜，注册成功，跳转到登陆页面！");
        } else {
            // 设置session属性
            session.setAttribute("registerMsg", "遗憾，注册失败！");
            // 重定向到注册页面
            response.sendRedirect(request.getContextPath() + "/frontend/register.jsp");
            System.out.println("遗憾，注册失败！,跳转到注册页面");
        }
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

测试：
)
确实在出现了控制台出现了：遗憾，注册失败！,跳转到注册页面，但是出现了没有捕获的异常：
com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for column ‘telephone’ at row 1,显示方式不是我们喜欢的，问题出现在模型层
修改UserDaoimpl.java
再次测试

package net.wlq.shop.servlet;
/**
 * 功能：显示类别控制程序
 * 作者：邓益春
 * 日期：2019年12月9日
 */

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import net.wlq.shop.bean.Category;
import net.wlq.shop.service.CategoryService;


@WebServlet("/showCategory")
public class ShowCategoryServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 创建类别服务对象
        CategoryService categoryService = new CategoryService();
        // 获取全部商品类别
        List<Category> categories = categoryService.findAllCategories();
        // 获取session对象
        HttpSession session = request.getSession();
        // 把商品类别列表以属性的方式保存到session里
        session.setAttribute("categories", categories);
        // 重定向到显示商品类别页面（showCategory.jsp）
        response.sendRedirect(request.getContextPath() + "/frontend/showCategory.jsp");
        for (Category category:categories){
            System.out.println(category);
        }
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

测试
显示商品处理类（ShowProductServlet）
`package net.wlq.shop.servlet;
/**

• 功能：显示商品列表的控制程序

• 通过业务层访问后台数据，
  

• 然后将数据返回给前台页面
  

• 作者：邓益春
• 日期：2019年12月9日
  */

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import net.wlq.shop.bean.Product;
import net.wlq.shop.service.CategoryService;
import net.wlq.shop.service.ProductService;

@WebServlet("/showProduct")
public class ShowProductServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    // 获取类别标识符
    int categoryId = Integer.parseInt(request.getParameter("categoryId"));
    // 创建商品类别服务对象
    CategoryService categoryService = new CategoryService();
    // 由类别标识符获取类别名
    String categoryName = categoryService.findCategoryById(categoryId).getName();
    // 创建商品服务对象
    ProductService productService = new ProductService();
    // 获取指定商品类别的商品列表
    List<Product> products = productService.findProductsByCategoryId(categoryId);
    // 获取session对象
    HttpSession session = request.getSession();
    // 把商品列表对象以属性的方式保存到session里
    session.setAttribute("products", products);
    // 重定向到显示商品信息页面
    response.sendRedirect(request.getContextPath() + "/frontend/showProduct.jsp?categoryName=" + categoryName);
    //
    for (int i =0;i<products.size();i++){
        System.out.println(products.get(i));
    }
}

protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    doGet(request, response);
}

}`
测试：

来源：CSDN

作者：hollp_to

链接：https://blog.csdn.net/hollp_to/article/details/103452367