数据库+js

算是具体例子的模板吧,功能还没全部完成，算是一个记录

goods管理

与数据库相连--Dbutil.java

package Good.Util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Dbutil {
 private static String className="com.mysql.jdbc.Driver";
 private static String url="jdbc:mysql://localhost:3306/eshop";
 private static String user="root";
 private static String password="";

 static {
  // (1)加载驱动：Class.forName(“”);
  try {
   Class.forName(className);
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  }
 }

 public static Connection getConnection(){
  // (2)获得连接驱动Connection
  Connection connection = null;
  try {
   connection = DriverManager.getConnection(url, user, password);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return connection;
 }

 /**
  * 关闭资源
  *
  * @param connection
  * @param statement
  * @param resultSet
  */
 public static void close(Connection connection, Statement statement, ResultSet resultSet) {
  if (resultSet != null) {
   try {
    resultSet.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
  if (statement != null) {
   try {
    statement.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
  if (connection != null) {
   try {
    connection.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
 }

 /**
  * 关闭资源
  *
  * @param connection
  * @param statement
  */
 public static void close(Connection connection, Statement statement) {
  if (statement != null) {
   try {
    statement.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
  if (connection != null) {
   try {
    connection.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
 }
}

写数据库中的类--Good.java

package Good.bean;

public class Good {
 private int id;
 private String name;
 private int number;
 private double price;
 private String depict;
 public Good() {
  
 }
 
 public Good(int id, String name, int number, double price, String depict) {
  super();
  this.id = id;
  this.name = name;
  this.number = number;
  this.price = price;
  this.depict = depict;
 }

 public int getId() {
  return id;
 }

 public void setId(int id) {
  this.id = id;
 }

 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

 public int getNumber() {
  return number;
 }

 public void setNumber(int number) {
  this.number = number;
 }

 public double getPrice() {
  return price;
 }

 public void setPrice(double price) {
  this.price = price;
 }

 public String getDepict() {
  return depict;
 }

 public void setDepict(String depict) {
  this.depict = depict;
 }

 @Override
 public String toString() {
  return "Good [id=" + id + ", name=" + name + ", number=" + number + ", price=" + price + ", depict=" + depict
    + "]";
 }
 
 
 

}

写Dao层--GoodDao.java

package Good.Dao;
import Good.bean.Good;
import jdk.nashorn.internal.ir.RuntimeNode.Request;
import Good.Util.Dbutil;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.sun.xml.internal.ws.api.config.management.policy.ManagementAssertion.Setting;

public class GoodDao {
 public static List list() {
  Connection connection = null;
  Statement statement = null;
  ResultSet resultSet = null;
  List list = new ArrayList<>();
  try {
   connection = Dbutil.getConnection();
   //3、写sql语句
   String sql = "select * from goods";
   //4、创建Statement（可以理解为一艘船，发送sql语句到服务器，如果是
   statement = connection.createStatement();
   //查询类的将结果集返回给浏览器，更新类返回的是影响的行数）
   //5、执行sql语句
   //     更新类：delete/update/insert   executeUpdate() 返回的是影响的行数
   //     查询类：select                           executeQuery()   返回的是结果集：ResultSet
   resultSet = statement.executeQuery(sql);
   
   while(resultSet.next()) {//遍历一行
    int id = resultSet.getInt("id");
    String name = resultSet.getString("name");
    int number = resultSet.getInt("number");
    double price = resultSet.getDouble("price");
    String depict = resultSet.getString("depict");
    Good goods = new Good(id, name, number, price, depict);
    list.add(goods);
   }
   for (Good goods : list) {
    System.out.println(goods);
   }
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   Dbutil.close(connection, statement, resultSet);
  }
  
  return list;
 }

 public static void deleteById(String id) {
  Connection connection = null;
  Statement statement = null;
  try {
   connection = Dbutil.getConnection();
   String sql = "delete from goods where id=" + id;
   statement = connection.createStatement();
   int count = statement.executeUpdate(sql);
   System.out.println("count: " + count);
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   Dbutil.close(connection, statement);
  }
 }

 public static Good find(String id) {
  Connection connection = null;
  Statement statement = null;
  ResultSet resultSet = null;
  Good good = new Good();
  try {
   System.out.println(id);
   connection = Dbutil.getConnection();
   String sql = "select * from goods where id="+id;
   statement = connection.createStatement();
   resultSet = statement.executeQuery(sql);
   
   while(resultSet.next()) {//遍历一行
    good.setId(resultSet.getInt("id"));
    good.setName(resultSet.getString("name"));
    good.setNumber(resultSet.getInt("number"));
    good.setPrice(resultSet.getDouble("price"));
    good.setDepict(resultSet.getString("depict"));
    System.out.println(good.getName());
   }
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   Dbutil.close(connection, statement, resultSet);
  }
  
  return good;
 }

 public static void change(String id, String name, String number, String price, String depict) {
  System.out.println("111"+number);
  System.out.println("111"+depict);
       
  Connection connection = null;
  Statement statement = null;
  ResultSet resultSet = null;
  try {
   System.out.println("修改！！");
   connection = Dbutil.getConnection();
   String sql = "UPDATE goods set name="+name+"number="+number+"price="+price+"depict="+depict+" where id="+id;
   statement = connection.createStatement();
   resultSet = statement.executeQuery(sql);
   System.out.println(number);
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   Dbutil.close(connection, statement, resultSet);
  }
 }

 
}

写与前端和Dao层相连的Servlet--Goodservlet

package Good.Servlet;

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 Good.Dao.GoodDao;
import Good.bean.Good;

/**
 * Servlet implementation class Goodservlet
 */
@WebServlet(urlPatterns={"/goods"})
public class Goodservlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
      
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Goodservlet() {
        super();
        // TODO Auto-generated constructor stub
    }

 /**
  * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 doPost(request, response); 
 }

 /**
  * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  String method = req.getParameter("method");
  System.out.println("method: " + method);
  if (method.equals("list")) {
   list(req, resp);
  } else if (method.equals("delete")) {
   delete(req, resp);
  } else if (method.equals("toEdit")) {
   toEdit(req, resp);
  }else if (method.equals("toFind")) {
   toFind(req, resp);
  }
 }
 
 private void toEdit(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  req.setCharacterEncoding("utf-8");
  String id=req.getParameter("id");
  String name=req.getParameter("name");
  String number=req.getParameter("number");
  String price=req.getParameter("price");
  String depict=req.getParameter("depict");
  System.out.println(depict);

  GoodDao.change(id,name,number,price,depict);
  list(req, resp);
 }
 
 private void toFind(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  String id=req.getParameter("id");
  Good good=GoodDao.find(id);
  req.setAttribute("good",good);
  //转发到界面展示
  req.getRequestDispatcher("Change.jsp").forward(req, resp);
  
 }

 /*
  * 删除
  */
 private void delete(HttpServletRequest req, HttpServletResponse resp) throws IOException {
  String id = req.getParameter("id");
  GoodDao.deleteById(id);
  resp.sendRedirect(req.getContextPath()+"/goods?method=list");
 }

 /*
  * 展示所有列表
  */
 private void list(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  List list = GoodDao.list();
  req.setAttribute("list", list);
  //转发到界面展示
  req.getRequestDispatcher("goods_list.jsp").forward(req, resp);
 }
}

前端页面1：进去的页面--NewFile.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>








商品管理
 

显示列表的页面--goods_list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8" import="java.util.*,Good.bean.*"%>
    <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

 <%
  List list = (List)request.getAttribute("list");
 %>
 
  
   
   
   
   
   
   
   
  
  <%
  if(list!=null){
   for(Good goods : list) {
  %>
   
    
    
    
    
    
    
    
   
  <% 
   }}
  
  %>
 

id	名字	库存	价格	描述	修改	删除
<%=goods.getId() %>	<%=goods.getName() %>	<%=goods.getNumber() %>	<%=goods.getPrice() %>	<%=goods.getDepict() %>	修改	删除

显示更新的页面--Change.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" import="java.util.*,Good.bean.*"%>

 <%
     request.setCharacterEncoding("utf-8");
     Good good=(Good)request.getAttribute("good");
     int id=good.getId();
     String name=good.getName();
     int number=good.getNumber();
     double price=good.getPrice();
     String depict=good.getDepict();
 %>
 
  
   
   
   
    name="id" id="id" >
    
    
    
    
    
    
    <%System.out.print("Change里显示"+depict);%>
    
   
   
  
 

id：<%=id%>

名称：

库存：

价格：

评价：