圖書商城（基於Jsp+Servlet）

本文轉載自查看原文 2019-12-13 17:33 409 Servlet、Jsp

這個項目主要是加深一下對於servlet和jsp知識相關的了解以及簡單業務邏輯的處理。

用戶更新的邏輯：

1.點擊修改用戶的那一行可以獲取到用戶的id

2.跳轉到一個servlet，去查詢該用戶的基本信息

3.查詢到后去到一個回顯用戶修改之前的基本信息的頁面

4.用戶點擊修改完成，跳轉一個servlet中去獲取修改信息

5.信息修改格式是否正確去調用一個服務層的方法

6.正確到用戶列表那一欄，錯誤到用戶修改界面。

分頁的實現：

    /**
     * 查詢所有用戶
     * @return
     */
    public static List<User> selAllUser(int pageNow,int showNum,String keyword) {
        Connection conn=null;
        PreparedStatement pstm=null;
        List<User> users = new ArrayList<>();
        //聲明結果集
        ResultSet rs = null;
        //獲取連接對象
        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+"%");
                 //(當前頁數-1)*一頁要展示多少條記錄（當前頁最開始的下標）
                 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]表示總記錄條數、arr[1]表示總頁數
     * @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;

    }

文件上傳部分代碼：

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 {

        //創建Smartupload對象
        SmartUpload smartUpload = new SmartUpload();
        //初始化
        smartUpload.initialize(this.getServletConfig(),request,response);
        //上傳過程
        try {
            smartUpload.upload();
        } catch (SmartUploadException e) {
            e.printStackTrace();
        }
        //獲取上傳文件對象
        Files files=smartUpload.getFiles();
        //獲取第一個
        File file=files.getFile(0);

        //獲取上傳文件名
        String fileName=file.getFileName();
        System.out.println(fileName);

        try {
            smartUpload.save("images/product");
        } catch (SmartUploadException e) {
            e.printStackTrace();
        }
        //獲取上傳的請求對象
        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("產品名稱"+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('添加失敗');");
            out.write("location.href='admin_doproductadd';");
            out.write("</script>");
            out.close();
        }
    }

}

Dao層對jdbc的簡單封裝：

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();
        }
    }
}