图书商城（基于Jsp+Servlet）

这个项目主要是加深一下对于servlet和jsp知识相关的了解以及简单业务逻辑的处理。

用户更新的逻辑：

1.点击修改用户的那一行可以获取到用户的id

2.跳转到一个servlet，去查询该用户的基本信息

3.查询到后去到一个回显用户修改之前的基本信息的页面

4.用户点击修改完成，跳转一个servlet中去获取修改信息

5.信息修改格式是否正确去调用一个服务层的方法

6.正确到用户列表那一栏，错误到用户修改界面。

分页的实现：

    /**

     * 查询所有用户

     * @return

     */

    public static List<User> selAllUser(int pageNow,int showNum,String keyword) {

        Connection conn=null;

        PreparedStatement pstm=null;

        List<User> users = new ArrayList<>();

        //声明结果集

        ResultSet rs = null;

        //获取连接对象

        try {

             conn = BaseDao.getConn();

             String sql="";

             if(keyword!=null){

                 sql="select * from user where USERNAME like ? order by USERBIRTHDAY limit ?,?";

                 pstm=conn.prepareStatement(sql);

                 pstm.setString(1,"%"+keyword+"%");

                 //(当前页数-1)*一页要展示多少条记录（当前页最开始的下标）

                 pstm.setInt(2,(pageNow-1)*showNum);

                 pstm.setInt(3,showNum);

             }else{

                 sql="select * from user order by USERBIRTHDAY limit ?,?";

                 pstm=conn.prepareStatement(sql);

                 pstm.setInt(1,(pageNow-1)*showNum);

                 pstm.setInt(2,showNum);

             }

             rs=pstm.executeQuery();

             while(rs.next()){

                 User user = new User(

                         rs.getString("USERID"),

                         rs.getString("USERNAME"),

                         rs.getString("USERPASSWORD"),

                         rs.getString("USERSEX"),

                         rs.getString("USERBIRTHDAY"),

                         rs.getString("USERIDENITYCODE"),

                         rs.getString("USEREMAIL"),

                         rs.getString("USERMOBILE"),

                         rs.getString("USERADDRESS"),

                         rs.getInt("USERSTATUS")

                 );

                 users.add(user);

             }

        } catch (SQLException e) {

            e.printStackTrace();

        }finally {

            BaseDao.closeall(rs,pstm,conn);

        }

        return users;

    }

    /**

     * arr[0]表示总记录条数、arr[1]表示总页数

     * @param showNum

     * @return arr

     */

    public static int[] totalPage(int showNum,String keyword){

    int []arr = {0,0};

    Connection conn = null;

    PreparedStatement pstm=null;

    ResultSet rs=null;

        try {

            conn=BaseDao.getConn();

            String sql="";

            if(keyword!=null){

                sql = "select count(*) from user where USERNAME like ?";

                pstm = conn.prepareStatement(sql);

                pstm.setString(1, "%"+keyword+"%");

            }else{

                sql="select count(*) from user";

                pstm=conn.prepareStatement(sql);

            }

            rs=pstm.executeQuery();

            while(rs.next()){

                arr[0]=rs.getInt(1);

                if(arr[0]%showNum==0){

                    arr[1]=arr[0]/showNum;

                }else{

                    arr[1]=(arr[0]/showNum)+1;

                }

            }

        } catch (SQLException e) {

            e.printStackTrace();

        }finally {

            BaseDao.closeall(rs,pstm,conn);

        }

    return arr;

    }

文件上传部分代码：

package com.zyb.servlet.product;

import com.jspsmart.upload.*;

import com.zyb.pojo.product;

import com.zyb.service.ProductService;

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 java.io.IOException;

import java.io.Writer;

@WebServlet("/manage/admin_doproductadd")

public class DoProductAdd extends HttpServlet {

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

        //创建Smartupload对象

        SmartUpload smartUpload = new SmartUpload();

        //初始化

        smartUpload.initialize(this.getServletConfig(),request,response);

        //上传过程

        try {

            smartUpload.upload();

        } catch (SmartUploadException e) {

            e.printStackTrace();

        }

        //获取上传文件对象

        Files files=smartUpload.getFiles();

        //获取第一个

        File file=files.getFile(0);

        //获取上传文件名

        String fileName=file.getFileName();

        System.out.println(fileName);

        try {

            smartUpload.save("images/product");

        } catch (SmartUploadException e) {

            e.printStackTrace();

        }

        //获取上传的请求对象

        Request req=smartUpload.getRequest();

        String name=req.getParameter("productName");

        //name=new String(name.getBytes("gbk"),"gbk");

        String id=req.getParameter("parentId");

        String price=req.getParameter("productPrice");

        String desc=req.getParameter("productDesc");

        //desc=new String(desc.getBytes("gbk"),"utf-8");

        String stock=req.getParameter("productStock");

        System.out.println("产品名称"+name);

        product p = new product(

          0,

          name,

          desc,

          Integer.parseInt(price),

          Integer.parseInt(stock),

          Integer.parseInt(id.split("-")[0] ),

          Integer.parseInt(id.split("-")[1] ),

          fileName

        );

        Writer out=response.getWriter();

        int mark = ProductService.insertProduct(p);

        if(mark>0){

            out.write("<script>");

            out.write("alert('添加成功');");

            out.write("location.href='admin_productsel';");

            out.write("</script>");

            out.close();

        }else{

            out.write("<script>");

            out.write("alert('添加失败');");

            out.write("location.href='admin_doproductadd';");

            out.write("</script>");

            out.close();

        }

    }

}

Dao层对jdbc的简单封装：

package com.zyb.dao;

import java.sql.*;

public class BaseDao {

    static {

        try {

            Class.forName("com.mysql.cj.jdbc.Driver");

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

    }

    public static Connection getConn() throws SQLException {

        Connection conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/shop?useSSL=false&serverTimezone=UTC","root","root");

        return conn;

    }

    public static int exeCRUD(String sql,Object []params){

        int cnt=0;

        PreparedStatement pstm=null;

        Connection conn = null;

        try {

            conn= BaseDao.getConn();

            pstm = conn.prepareStatement(sql);

            for(int i=0; i<params.length; i++) {

                pstm.setObject(i+1, params[i]);

            }

            cnt = pstm.executeUpdate();

        } catch (SQLException e) {

            e.printStackTrace();

        }finally {

            BaseDao.closeall(null, pstm, conn);

        }

        return cnt;

    }

    public static void closeall(ResultSet rs, PreparedStatement ps, Connection conn) {

        try {

            if(rs!=null)

                rs.close();

            if(ps!=null)

                ps.close();

            if(conn!=null)

                conn.close();

        } catch (SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

}