库存管理系统

该代码只能实现商品的增删改查。
 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>首页</title>
 8 
 9 </head>
10 <body>
11     <div align="center">
12         
13         <div class="a">
14             <a href="add.jsp">商品信息添加</a>
15         </div>
16         <div class="a">
17             <a href="CourseServlet?method=list">商品信息修改</a>
18         </div>
19         <div class="a">
20             <a href="del.jsp">商品信息删除</a>
21         </div>
22         <div class="a">
23             <a href="search.jsp">商品信息查询</a>
24         </div>
25     </div>
26 </body>
27 </html>

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10     <%
11          Object message = request.getAttribute("message");
12          if(message!=null && !"".equals(message)){
13      
14     %>
15          <script type="text/javascript">
16               alert("<%=request.getAttribute("message")%>");
17          </script>
18     <%} %>
19 <div align="center">
20         <h1 style="color: black;">商品信息录入</h1>
21         <a href="index.jsp">返回主页</a>
22         <form action="CourseServlet?method=add" method="post" onsubmit="return check()">
23             <div class="a">
24                 商品名称<input type="text" id="name" name="name"/>
25             </div>
26             <div class="a">
27                 商品生产厂家<input type="text" id="chanjia" name="chanjia" />
28             </div>
29             <div class="a">
30                 商品型号<input type="text" id="number" name="number" />
31             </div>
32             <div class="a">
33                 商品规格<input type="text" id="guige" name="guige"/>
34             </div>
35             <div class="a">
36                 商品日期<input type="text" id="riqi" name="riqi"/>
37             </div>    
38             <div class="a">
39                 商品时间<input type="text" id="time" name="time"/>
40             </div>    
41             <div class="a">
42                 入库单位名称<input type="text" id="ruku" name="ruku"/>
43             </div>    
44             <div class="a">
45                 送货人姓名<input type="text" id="songhuo" name="songhuo"/>
46             </div>    
47             <div class="a">
48                 <button type="submit" class="b">保&nbsp;&nbsp;&nbsp;存</button>
49             </div>
50         </form>
51     </div>
52     <script type="text/javascript">
53         function check() {
54             var name = document.getElementById("name");;
55             var chanjia = document.getElementById("chanjia");
56             var number = document.getElementById("number");
57             var guige = document.getElementById("guige");
58         }
59 </body>
60 </html>

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>Insert title here</title>
 8 
 9 </head>
10 <body>
11     <%
12          Object message = request.getAttribute("message");
13          if(message!=null && !"".equals(message)){
14      
15     %>
16          <script type="text/javascript">
17               alert("<%=request.getAttribute("message")%>");
18          </script>
19     <%} %>
20     <div align="center">
21         <h1 style="color: black;">商品信息删除</h1>
22         <a href="index.jsp">返回主页</a>
23         <form action="CourseServlet?method=getcoursebyname" method="post" onsubmit="return check()">
24             <div class="a">
25                 商品名称<input type="text" id="name" name="name"/>
26             </div>
27             <div class="a">
28                 <button type="submit" class="b">查&nbsp;&nbsp;&nbsp;找</button>
29             </div>
30         </form>
31     </div>
32     <script type="text/javascript">
33         function check() {
34             var name = document.getElementById("name");;
35             
36             //非空
37             if(name.value == '') {
38                 alert('商品名称为空');
39                 name.focus();
40                 return false;
41             }
42         }
43     </script>
44 </body>
45 </html>

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>Insert title here</title>
 8 <style>
 9     .a{
10         margin-top: 20px;
11     }
12     .b{
13         font-size: 20px;
14         width: 160px;
15         color: white;
16         background-color: greenyellow;
17     }
18     .tb, td {
19         border: 1px solid black;
20         font-size: 22px;
21     }
22 </style>
23 </head>
24 <body>
25     <div align="center">
26         <h1 style="color: black;">商品信息删除</h1>
27         <a href="index.jsp">返回主页</a>
28         <table class="tb">
29             <tr>
30                 <td>商品名称</td>
31                 <td>${course.name}</td>
32             </tr>
33             <tr>
34                 <td>商品上产产家</td>
35                 <td>${course.chanjia}</td>
36             </tr>
37             <tr>
38                 <td>商品型号</td>
39                 <td>${course.number}</td>
40             </tr>
41             <tr>
42                 <td>商品规格</td>
43                 <td>${course.guige}</td>
44             </tr>
45             <tr>
46                 <td>商品日期</td>
47                 <td>${course.riqi}</td>
48             </tr>
49             <tr>
50                 <td>商品时间</td>
51                 <td>${course.time}</td>
52             </tr>
53             <tr>
54                 <td>入库单位名称</td>
55                 <td>${course.ruku}</td>
56             </tr>
57             <tr>
58                 <td>送货人姓名</td>
59                 <td>${course.songhuo}</td>
60             </tr>
61         </table>
62         <div class="a">
63             <a onclick="return check()" href="CourseServlet?method=del&id=${course.id}">删&nbsp;&nbsp;&nbsp;除</a>
64         </div>
65     </div>
66     <script type="text/javascript">
67         function check() {
68             if (confirm("真的要删除吗？")){
69                 return true;
70             }else{
71                 return false;
72             }
73         }
74     </script>
75 </body>
76 </html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>

</head>
<body>
    <%
         Object message = request.getAttribute("message");
         if(message!=null && !"".equals(message)){
     
    %>
         <script type="text/javascript">
              alert("<%=request.getAttribute("message")%>");
         </script>
    <%} %>
    <div align="center">
        <h1 style="color: black;">商品信息列表</h1>
        <a href="index.jsp">返回主页</a>
        <table class="tb">
            <tr>
                <td>id</td>
                <td>商品名称</td>
                <td>商品生产产家</td>
                <td>商品型号</td>
                <td>商品规格</td>
                <td>商品日期</td>
                <td>商品时间</td>
                <td>入库单位名称</td>
                <td>送货人姓名</td>
                <td align="center" colspan="2">操作</td>
            </tr>
            <c:forEach items="${courses}" var="item">
                <tr>
                    <td>${item.id}</td>
                    <td>${item.name}</td>
                    <td>${item.chanjia}</td>
                    <td>${item.number}</td>
                    <td>${item.guige}</td>
                    <td>${item.riqi}</td>
                    <td>${item.time}</td>
                    <td>${item.ruku}</td>
                    <td>${item.songhuo}</td>
                    <td><a href="CourseServlet?method=getcoursebyid&id=${item.id}">修改</a></td>
                </tr>
            </c:forEach>
        </table>
    </div>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>

</head>
<body>
    <div align="center">
        <h1 style="color: black;">商品信息查询</h1>
        <a href="index.jsp">返回主页</a>
        <form action="CourseServlet?method=search" method="post" onsubmit="return check()">
            <div class="a">
                商品名称<input type="text" id="name" name="name"/>
            </div>
            <div class="a">
                商品生产产家<input type="text" id="chanjia" name="chanjia" />
            </div>
            <div class="a">
                商品型号<input type="text" id="number" name="number" />
            </div>
            <div class="a">
                商品规格<input type="text" id="guige" name="guige" />
            </div>
            <div class="a">
                商品日期<input type="text" id="riqi" name="riqi" />
            </div>
            <div class="a">
                商品时间<input type="text" id="time" name="time" />
            </div>
            <div class="a">
                入库单位名称<input type="text" id="ruku" name="ruku" />
            </div>
            <div class="a">
                送货人姓名<input type="text" id="songhuo" name="songhuo" />
            </div>
            <div class="a">
                <button type="submit" class="b">查&nbsp;&nbsp;&nbsp;询</button>
            </div>
        </form>
    </div>
    <script type="text/javascript">
        function check() {
            var name = document.getElementById("name");;
            var chanjia = document.getElementById("chanjia");
            var number = document.getElementById("number");
            var guige = document.getElementById("guige");
            var riqi = document.getElementById("riqi");
            var time = document.getElementById("time");
            var ruku = document.getElementById("ruku");
            var songhuo = document.getElementById("songhuo");
            
            //非空
            if(name.value == '' && chanjia.value == '' && number.value == ''&& guige.value == ''&& riqi.value == ''&& time.value == ''&& ruku.value == ''&& songhuo.value == '') {
                alert('请填写一个条件');
                return false;
            }
        }
    </script>
</body>
</html>

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
 4 <!DOCTYPE html>
 5 <html>
 6 <head>
 7 <meta charset="UTF-8">
 8 <title>Insert title here</title>
 9 
10 </head>
11 <body>
12     <div align="center">
13         <h1 style="color: black;">商品信息列表</h1>
14         <a href="index.jsp">返回主页</a>
15         <table class="tb">
16             <tr>
17                 <td>id</td>
18                 <td>商品名称</td>
19                 <td>商品上产产家</td>
20                 <td>商品型号</td>
21                 <td>商品规格</td>
22                 <td>商品日期</td>
23                 <td>商品时间</td>
24                 <td>入库单位名称</td>
25                 <td>送货人姓名</td>
26             </tr>
27             <!-- forEach遍历出adminBeans -->
28             <c:forEach items="${courses}" var="item" varStatus="status">
29                 <tr>
30                     <td>${item.id}</td>
31                     <td><a>${item.name}</a></td>
32                     <td>${item.chanjia}</td>
33                     <td>${item.number}</td>
34                     <td>${item.guige}</td>
35                     <td>${item.riqi}</td>
36                     <td>${item.time}</td>
37                     <td>${item.ruku}</td>
38                     <td>${item.songhuo}</td>
39                 </tr>
40             </c:forEach>
41         </table>
42     </div>
43 </body>
44 </html>

下面是src包的代码

package com.hjf.dao;

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

import com.hjf.entity.Course;
import com.hjf.util.DBUtil;


public class CourseDao {

/**
* 添加
* @param course
* @return
*/
public boolean add(Course shangpin) {
String sql = "insert into shangpin(name, chanjia, number, guige, riqi, time, ruku, songhuo) values('" + shangpin.getName() + "','" + shangpin.getChanjia() + "','" + shangpin.getNumber() + "','" + shangpin.getGuige() + "','" + shangpin.getRiqi() + "','" + shangpin.getTime() + "','" + shangpin.getRuku() + "','" + shangpin.getSonghuo() + "')";
//创建数据库链接
Connection conn = DBUtil.getConn();
Statement state = null;
boolean f = false;
int a = 0;

try {
state = conn.createStatement();
state.executeUpdate(sql);
} catch (Exception e) {
e.printStackTrace();
} finally {
//关闭连接
DBUtil.close(state, conn);
}

if (a > 0) {
f = true;
}
return f;
}

/**
* 删除
* 
* @param id
* @return
*/
public boolean delete (int id) {
boolean f = false;
String sql = "delete from shangpin where id='" + id + "'";

Connection conn = DBUtil.getConn();
Statement state = null;
int a = 0;

try {
state = conn.createStatement();
a = state.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(state, conn);
}

if (a > 0) {
f = true;
}
return f;
}

/**
* 修改
* @param name
* @param pass
*/
public boolean update(Course shangpin) {
String sql = "update shangpin set name='" + shangpin.getName() + "', chanjia='" + shangpin.getChanjia() + "', number='" + shangpin.getNumber()+"', guige='"+shangpin.getGuige()+ "', riqi='" + shangpin.getRiqi() + "', time='" + shangpin.getTime() + "', ruku='" + shangpin.getRuku() + "', songhuo='" + shangpin.getSonghuo() +
"' where id='" + shangpin.getId() + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
boolean f = false;
int a = 0;

try {
state = conn.createStatement();
a = state.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(state, conn);
}

if (a > 0) {
f = true;
}
return f;
}

/**
* 验证课程名称是否唯一
* true --- 不唯一
* @param name
* @return
*/
public boolean name(String name) {
boolean flag = false;
String sql = "select name from shangpin where name = '" + name + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;

try {
state = conn.createStatement();
rs = state.executeQuery(sql);
while (rs.next()) {
flag = true;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}
return flag;
}

/**
* 通过ID得到课程信息
* @param id
* @return
*/
public Course getCourseById(int id) {
String sql = "select * from shangpin where id ='" + id + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
Course shangpin = null;

try {
state = conn.createStatement();
rs = state.executeQuery(sql);
while (rs.next()) {
String name = rs.getString("name");
String chanjia = rs.getString("chanjia");
String number = rs.getString("number");
String guige = rs.getString("guige");
String riqi = rs.getString("riqi");
String time = rs.getString("time");
String ruku = rs.getString("ruku");
String songhuo = rs.getString("songhuo");
shangpin = new Course(id, name, chanjia, number,guige,riqi, time, ruku, songhuo);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}

return shangpin;
}

/**
* 通过name得到Course
* @param name
* @return
*/
public Course getCourseByName(String name) {
String sql = "select * from shangpin where name ='" + name + "'";
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;
Course shangpin = null;

try {
state = conn.createStatement();
rs = state.executeQuery(sql);
while (rs.next()) {
int id = rs.getInt("id");
String chanjia = rs.getString("chanjia");
String number = rs.getString("number");
String guige = rs.getString("guige");
String riqi = rs.getString("riqi");
String time = rs.getString("time");
String ruku = rs.getString("ruku");
String songhuo = rs.getString("songhuo");
shangpin = new Course(id, name, chanjia, number,guige,riqi, time, ruku, songhuo);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}

return shangpin;
}

/**
* 查找
* @param name
* @param teacher
* @param classroom
* @return
*/
public List<Course> search(String name, String chanjia, String number,String guige,String riqi,String time,String ruku,String songhuo) {
String sql = "select * from shangpin where ";
if (name != "") {
sql += "name like '%" + name + "%'";
}
if (chanjia != "") {
sql += " chanjia like '%" + chanjia + "%'";
}
if (number != "") {
sql += " number like '%" + number + "%'";
}
if (guige != "") {
sql += " guige like '%" + guige + "%'";
}
if (riqi != "") {
sql += " guige like '%" + riqi + "%'";
}
if (time != "") {
sql += " guige like '%" + time + "%'";
}
if (ruku != "") {
sql += " guige like '%" + ruku + "%'";
}
if (songhuo != "") {
sql += " guige like '%" + songhuo + "%'";
}
List<Course> list = new ArrayList<>();
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;

try {
state = conn.createStatement();
rs = state.executeQuery(sql);
Course bean = null;
while (rs.next()) {
int id = rs.getInt("id");
String name2 = rs.getString("name");
String chanjia2 = rs.getString("chanjia");
String number2 = rs.getString("number");
String guige2 = rs.getString("guige");
String riqi2 = rs.getString("riqi");
String time2 = rs.getString("time");
String ruku2 = rs.getString("ruku");
String songhuo2 = rs.getString("songhuo");
bean = new Course(id, name2, chanjia2, number2,guige2,riqi2, time2, ruku2, songhuo2);
list.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}

return list;
}

/**
* 全部数据
* @param name
* @param teacher
* @param classroom
* @return
*/
public List<Course> list() {
String sql = "select * from shangpin";
List<Course> list = new ArrayList<>();
Connection conn = DBUtil.getConn();
Statement state = null;
ResultSet rs = null;

try {
state = conn.createStatement();
rs = state.executeQuery(sql);
Course bean = null;
while (rs.next()) {
int id = rs.getInt("id");
String name2 = rs.getString("name");
String chanjia2 = rs.getString("chanjia");
String number2 = rs.getString("number");
String guige2 = rs.getString("guige");
String riqi2 = rs.getString("riqi");
String time2 = rs.getString("time");
String ruku2 = rs.getString("ruku");
String songhuo2 = rs.getString("songhuo");
bean = new Course(id, name2, chanjia2, number2,guige2,riqi2, time2, ruku2, songhuo2);
list.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBUtil.close(rs, state, conn);
}

return list;
}

}

package com.hjf.entity;

public class Course {

private int id;
private String name;
private String chanjia;
private String number;
private String guige;
private String riqi;
private String time;
private String ruku;
private String songhuo;
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 String getChanjia() {
return chanjia;
}
public void setTeacher(String chanjia) {
this.chanjia = chanjia;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public String getGuige() {
return guige;
}
public void setGuige(String guige) {
this.guige= guige;
}
public String getRiqi() {
return riqi;
}
public void setRiqi(String riqi) {
this.riqi = riqi;
}
public String getTime() {
return time;
}
public void setTime(String time) {
this.time = time;
}
public String getRuku() {
return ruku;
}
public void setRuku(String ruku) {
this.ruku =ruku;
}
public String getSonghuo() {
return songhuo;
}
public void setSonghuo(String songhuo) {
this.songhuo =songhuo;
}
public Course() {}

public Course(int id, String name, String chanjia, String number,String guige,String riqi,String time,String ruku,String songhuo) {
this.id = id;
this.name = name;
this.chanjia = chanjia;
this.number = number;
this.guige=guige;
this.riqi=riqi;
this.time=time;
this.ruku=ruku;
this.songhuo=songhuo;
}

public Course(String name, String chanjia, String number,String guige,String riqi,String time,String ruku,String songhuo) {
this.name = name;
this.chanjia = chanjia;
this.number = number;
this.guige=guige;
this.riqi=riqi;
this.time=time;
this.ruku=ruku;
this.songhuo=songhuo;
}
}

package com.hjf.service;

import java.util.List;

import com.hjf.dao.CourseDao;
import com.hjf.entity.Course;

/**
* CourseService
* 服务层
* @author Hu
*
*/
public class CourseService {

CourseDao cDao = new CourseDao();

/**
* 添加
* @param course
* @return
*/
public boolean add(Course shangpin) {
boolean f = false;
if(!cDao.name(shangpin.getName())) {
cDao.add(shangpin);
f = true;
}
return f;
}

/**
* 删除
*/
public void del(int id) {
cDao.delete(id);
}

/**
* 修改
* @return
*/
public void update(Course shangpin) {
cDao.update(shangpin);
}

/**
* 通过ID得到一个Course
* @return
*/
public Course getCourseById(int id) {
return cDao.getCourseById(id);
}

/**
* 通过Name得到一个Course
* @return
*/
public Course getCourseByName(String name) {
return cDao.getCourseByName(name);
}

/**
* 查找
* @return
*/
public List<Course> search(String name, String chanjia, String number,String guige,String riqi,String time,String ruku,String songhuo) {
return cDao.search(name,chanjia,number,guige,riqi,time,ruku,songhuo);
}

/**
* 全部数据
* @return
*/
public List<Course> list() {
return cDao.list();
}
}

package com.hjf.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 com.hjf.entity.Course;
import com.hjf.service.CourseService;

@WebServlet("/CourseServlet")
public class CourseServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

CourseService service = new CourseService();

/**
* 方法选择
*/
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
String method = req.getParameter("method");

if ("add".equals(method)) {
add(req, resp);
} else if ("del".equals(method)) {
del(req, resp);
} else if ("update".equals(method)) {
update(req, resp);
} else if ("search".equals(method)) {
search(req, resp);
} else if ("getcoursebyid".equals(method)) {
getCourseById(req, resp);
} else if ("getcoursebyname".equals(method)) {
getCourseByName(req, resp);
} else if ("list".equals(method)) {
list(req, resp);
}
}

/**
* 添加
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
req.setCharacterEncoding("utf-8");
//获取数据
String name = req.getParameter("name");
String chanjia = req.getParameter("chanjia");
String number = req.getParameter("number");
String guige = req.getParameter("guige");
String riqi = req.getParameter("riqi");
String time = req.getParameter("time");
String ruku = req.getParameter("ruku");
String songhuo = req.getParameter("songhuo");
Course shangpin = new Course(name,chanjia,number, guige,riqi,time,ruku,songhuo);

//添加后消息显示
if(service.add(shangpin)) {
req.setAttribute("message", "添加成功");
req.getRequestDispatcher("add.jsp").forward(req,resp);
} else {
req.setAttribute("message", "课程名称重复，请重新录入");
req.getRequestDispatcher("add.jsp").forward(req,resp);
}
}

/**
* 全部
* @param req
* @param resp
* @throws ServletException
*/
private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");

List<Course> shangpin = service.list();
req.setAttribute("courses", shangpin);
req.getRequestDispatcher("list.jsp").forward(req,resp);
}

/**
* 通过ID得到Course
* @param req
* @param resp
* @throws ServletException
*/
private void getCourseById(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
int id = Integer.parseInt(req.getParameter("id"));
Course shangpin = service.getCourseById(id);
req.setAttribute("courses", shangpin);
req.getRequestDispatcher("detail2.jsp").forward(req,resp);
}

/**
* 通过名字查找
* 跳转至删除
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void getCourseByName(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
String name = req.getParameter("name");
Course shangpin = service.getCourseByName(name);
if(shangpin == null) {
req.setAttribute("message", "查无此商品！");
req.getRequestDispatcher("del.jsp").forward(req,resp);
} else {
req.setAttribute("courses", shangpin);
req.getRequestDispatcher("detail.jsp").forward(req,resp);
}
}

/**
* 删除
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void del(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
int id = Integer.parseInt(req.getParameter("id"));
service.del(id);
req.setAttribute("message", "删除成功！");
req.getRequestDispatcher("del.jsp").forward(req,resp);
}

/**
* 修改
* @param req
* @param resp
* @throws IOException
* @throws ServletException
*/
private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
int id = Integer.parseInt(req.getParameter("id"));
String name = req.getParameter("name");
String chanjia = req.getParameter("chanjia");
String number = req.getParameter("number");
String guige = req.getParameter("guige");
String riqi = req.getParameter("riqi");
String time = req.getParameter("time");
String ruku = req.getParameter("ruku");
String songhuo = req.getParameter("songhuo");
Course shangpin = new Course(name, chanjia,number, guige,riqi,time,ruku,songhuo);

service.update(shangpin);
req.setAttribute("message", "修改成功");
req.getRequestDispatcher("CourseServlet?method=list").forward(req,resp);
}

/**
* 查找
* @param req
* @param resp
* @throws ServletException
*/
private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
req.setCharacterEncoding("utf-8");
String name = req.getParameter("name");
String chanjia = req.getParameter("chanjia");
String number = req.getParameter("number");
String guige = req.getParameter("guige");
String riqi = req.getParameter("riqi");
String time = req.getParameter("time");
String ruku = req.getParameter("ruku");
String songhuo = req.getParameter("songhuo");
List<Course> shangpin = service.search(name, chanjia,number, guige,riqi,time,ruku,songhuo);
req.setAttribute("courses", shangpin);
req.getRequestDispatcher("searchlist.jsp").forward(req,resp);
}
}

package com.hjf.util;

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

/**
 * 数据库连接工具
 * @author Hu
 *
 */
public class DBUtil {
    
    public static String db_url = "jdbc:mysql://localhost:3306/shangpin?useUnicode=true&characterEncoding=utf8&useSSL=false";
    public static String db_user = "root";
    public static String db_pass = "123";
    
    public static Connection getConn () {
        Connection conn = null;
        
        try {
            Class.forName("com.mysql.jdbc.Driver");//加载驱动
            conn = DriverManager.getConnection(db_url, db_user, db_pass);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return conn;
    }
    
    /**
     * 关闭连接
     * @param state
     * @param conn
     */
    public static void close (Statement state, Connection conn) {
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void close (ResultSet rs, Statement state, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) throws SQLException {
        Connection conn = getConn();
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        String sql ="select * from course";
        pstmt = conn.prepareStatement(sql);
        rs = pstmt.executeQuery();
        if(rs.next()){
            System.out.println("空");
        }else{
            System.out.println("不空");
        }
    }
}