此项目做的事一个课程管理系统，需要通过web做一个可以实现课程的增删改查的功能。
需要用到数据库，Servlet和jsp等（第一次使用Servlet和数据库连接，所以代码都比较低级，页面也比较粗糙，还没有实现Servlet处理后数据的回传，还未实现模糊查询）
程序所建的项目如下：
1.首先建立数据库链接
course/src/com.jdbc.util/BaseConnection.java
代码如下：
1 package com.jdbc.util;
2
3
4 import java.sql.Connection;
5 import java.sql.DriverManager;
6
7 public class BaseConnection {
8
9 public static Connection getConnection(){//用这个方法获取mysql的连接
10 Connection conn=null;
11 String driver = "com.mysql.jdbc.Driver";
12 String url = "jdbc:mysql://localhost:3306/sql?characterEncoding=utf8&useSSL=true";
13 String user = "root";
14 String password = "";//此处填写数据库连接密码
15 try{
16 Class.forName(driver);//加载驱动类
17 conn=DriverManager.
18 getConnection(url,user,password);//（url数据库的IP地址，user数据库用户名，password数据库密码）
19 }catch(Exception e){
20 e.printStackTrace();
21 }
22 return conn;
23 }
24
25 public static void main(String[] args) {
26 System.out.println("连接成功");
27 }
28 }
利用javabean建立一个课程类：
course/src/com.jdbc.bean/Course:
代码如下：
1 package com.jdbc.bean;
2
3 public class Course {
4
5 private String classname;
6 private String teacher;
7 private String place;
8
9 public String getClassname() {
10 return classname;
11 }
12 public void setClassname(String classname) {
13 this.classname = classname;
14 }
15 public String getTeacher() {
16 return teacher;
17 }
18 public void setTeacher(String teacher) {
19 this.teacher = teacher;
20 }
21 public String getPlace() {
22 return place;
23 }
24 public void setPlace(String place) {
25 this.place = place;
26 }
27
28
29
30 }
为了后期操作的方便我将一些增删改查的方法写到了一个类中，把他们封装为一个一个的具体的方法
course/src/com.jdbc.dao/JdbcMain.java
代码如下：
1 package com.jdbc.dao;
2
3
4 import java.sql.Connection;
5 import java.sql.PreparedStatement;
6 import java.sql.ResultSet;
7 import java.sql.SQLException;
8 import java.util.Scanner;
9
10 import com.jdbc.bean.Course;
11 import com.jdbc.util.BaseConnection;
12
13 public class JdbcMain {
14 static Scanner in = new Scanner(System.in);
15 public static void main(String[] args) {
16 // TODO 自动生成的方法存根
17
18
19 }
20
21
22 public static int add(Course cour)
23 {
24 Connection conn= BaseConnection.getConnection();
25
26 String sql = "insert into course values(?,?,?)";
27
28 int b = 0;
29 PreparedStatement ps=null;
30 try{
31
32 ps= conn.prepareStatement(sql);//把写好的sql语句传递到数据库，让数据库知道我们要干什么
33
34 ps.setString(1,cour.getClassname());
35
36 ps.setString(2,cour.getTeacher());
37
38 ps.setString(3, cour.getPlace());
39
40 int a=ps.executeUpdate();//这个方法用于改变数据库数据，a代表改变数据库的条数
41 if(a>0){
42 b++;
43 System.out.println("添加成功");
44
45 }else{
46 System.out.println("添加失败");
47
48 }
49 }catch(Exception e){
50 e.printStackTrace();
51 }try{
52 if(ps!=null){
53 ps.close();
54 }if(conn!=null){
55 conn.close();
56 }
57 }catch(Exception e2){
58 e2.printStackTrace();
59 }
60
61 return b;
62 }
63
64
65
66 public static int update(Course cour )
67 {
68 int b = 0;
69
70 Connection conn= BaseConnection.getConnection();
71 PreparedStatement ps=null;
72 String sql="update course set place=?,teacher=? where class=?";
73 try{
74 ps=conn.prepareStatement(sql);
75
76 ps.setString(1,cour.getPlace());
77 ps.setString(2,cour.getTeacher());
78 ps.setString(3,cour.getClassname());
79 int a=ps.executeUpdate();
80 if(a>0){
81 b++;
82 System.out.println("修改成功");
83 }else{
84 System.out.println("修改失败");
85 }
86 }catch(Exception e){
87 e.printStackTrace();
88 }finally{
89 try{
90 if(ps!=null){
91 ps.close();
92 }if(conn!=null){
93 conn.close();
94 }
95 }catch(Exception e2){
96 e2.printStackTrace();
97 }
98 }
99
100
101 return b;
102 }
103
104
105 public static int delete(String classname)
106
107 {
108 int b = 0;
109 Connection conn=BaseConnection.getConnection();
110 PreparedStatement ps=null;
111 String sql="delete from course where class =?";
112
113 try{
114 ps=conn.prepareStatement(sql);
115 ps.setString(1, classname);
116 int a=ps.executeUpdate();
117 if(a>0){
118 b++;
119 System.out.println("删除成功");
120 }else{
121 System.out.println("删除失败");
122 }
123 }catch(Exception e){
124 e.printStackTrace();
125 }finally{
126 try{
127 if(ps!=null){
128 ps.close();
129 }if(conn!=null){
130 conn.close();
131 }
132 }catch(Exception e2){
133 e2.printStackTrace();
134 }
135 }
136 return b;
137 }
138
139 public static Course find(String s)
140 {
141 Connection conn= BaseConnection.getConnection();
142 PreparedStatement ps=null;
143
144 ResultSet rs = null;
145
146 Course cour = new Course();
147
148 String sql="select * from course where class =?";
149
150 try {
151 ps=conn.prepareStatement(sql);
152
153 ps.setString(1, s);
154 rs=ps.executeQuery();
155 if(rs.next()){
156 cour.setClassname(rs.getString("class"));
157 cour.setTeacher(rs.getString("teacher"));
158 cour.setPlace(rs.getString("place"));
159
160 }
161
162
163
164 } catch (SQLException e) {
165 // TODO 自动生成的 catch 块
166 e.printStackTrace();
167 } finally{
168 try{
169 if(ps!=null){
170 ps.close();
171 }if(conn!=null){
172 conn.close();
173 }
174 if(rs!=null)
175 {
176 rs.close();
177 }
178 }catch(Exception e2){
179 e2.printStackTrace();
180 }
181 }
182
183 return cour;
184 }
185
186
187
188 }
下面建立主界面：
主界面主要就是在界面中介入了多个链接，通过对链接的点击，进行页面的跳转，实现不同的操作。
路径 /course/WebContent/admin/main.jsp
代码如下：
1 <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> 2 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 3 <!DOCTYPE html> 4 <html> 5 <head> 6 <meta charset="UTF-8"> 7 <title>主页面</title> 8 </head> 9 <body> 10 11 <a href="javascript:location.reload()">刷新页面</a></br> 12 <a href="add.jsp" target="iframe_a">增加课程</a></br> 13 <a href="delete.jsp" target="iframe_a">删除课程</a></br> 14 <a href="update.jsp" target="iframe_a">修改课程</a></br> 15 <a href="find.jsp" target="iframe_a">查询课程</a></br> 16 <a href="ShowAll.jsp" target="iframe_a">显示全部课程</a> 17 18 19 </body> 20 </html>
课程添加页面：
路径/course/WebContent/admin/add.jsp
代码如下：
1 <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
2 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
3 <html>
4 <head>
5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
6 <title>Insert title here</title>
7 </head>
8 <body>
9 <form action="${pageContext.request.contextPath}/Manage?method=add" method="post" id="add">
10
11 课程名称：<input name = "class" type = "text" ></br>
12 任课教师：<input name = "teacher" type = "text"></br>
13 上课地点：<input name = "place" type = "text"></br>
14 <input type="submit"value="保存" >
15
16 </form>
17 </body>
18 </html>
删除页面：主要操作就是通过课程名称找到课程位置，输出一下他的具体信息并将其删除
路径/course/WebContent/admin/delete.jsp
代码如下：
1 <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
2 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
3 <html>
4 <head>
5 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
6 <title>删除界面</title>
7 </head>
8 <body>
9 <form action="${pageContext.request.contextPath}/Manage?method=delete" method="post" id="delete">
10
11
12 输入您要删除的课程：<input type = "text" name = "class">
13
14 <input type="submit"value="提交" >
15 </form>
16 </body>
17 </html>
修改页面：通过课程名称进行搜索，并对课程信息进行修改，现在还存在的问题是都是通过课程名称找到的还能修改课程名称。
路径/course/WebContent/admin/update.jsp
代码如下：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>修改课程信息</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/Manage?method=update" method="post" id="update">
课程名称：<input name = "class" type = "text"></br>
任课教师：<input name = "teacher" type = "text"></br>
上课地点：<input name = "place" type = "text"></br>
<input type="submit"value="提交" >
</form>
</body>
</html>
查找界面:现在只实现了通过课程名称查找，还没有实现模糊查询
路径/course/WebContent/admin/find.jsp
代码如下：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>查找</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/Manage?method=find" method="post" id="find">
课程名称：<input name = "class" type = "text">
<input type="submit"value="提交" >
</form>
</body>
</html>
显示所有页面：输出数据库中的全部数据
路径/course/WebContent/admin/show.jsp
代码如下：
1 <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
2
3 <%@page import="com.jdbc.dao.JdbcMain"%>
4 <%@page import="com.jdbc.util.BaseConnection"%>
5 <%@page import="java.sql.PreparedStatement"%>
6 <%@page import="java.sql.ResultSet"%>
7 <%@page import="java.sql.SQLException"%>
8 <%@page import="java.sql.Connection"%>
9
10 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
11 <html>
12 <head>
13 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
14 <title>显示全部</title>
15 </head>
16 <body>
17 <form name = "form6" action = "main.jsp" method = "post">
18 <%
19
20 Connection conn= BaseConnection.getConnection();
21 PreparedStatement ps=null;
22 ResultSet rs = null;
23 String sql = "select * from course";
24 try {
25 ps=conn.prepareStatement(sql);
26 rs=ps.executeQuery();//执行数据库查询的方法，放到rs中
27
28
29 String classname = null;
30 String teacher = null;
31 String place = null;
32 while(rs.next()){
33
34 classname = rs.getString("class");
35
36 teacher = rs.getString("teacher");
37 place = rs.getString("place");
38
39 //输出结果
40 out.println(classname + "\t" + teacher + ‘\t‘ + place + "</br>");
41 }
42
43 } catch (SQLException e) {
44 // TODO 自动生成的 catch 块
45 e.printStackTrace();
46 }finally{
47 try{
48 if(ps!=null){
49 ps.close();
50 }if(conn!=null){
51 conn.close();
52 }if(rs!=null)
53 {
54 rs.close();
55 }
56 }catch(Exception e2){
57 e2.printStackTrace();
58 }
59 }
60
61
62
63
64
65
66 %>
67 <input type = "submit" value = "返回" >
68 </form>
69 </body>
70 </html>
根据界面出入的数据，都将其传入Servlet中然后对其进行处理，由于不会使用数据的回传，无法通过页面的形式给出提示信息，所以就用java的提示框进行对结果的提示了
Servlet路径/course/src/servelet/Manage.java
代码如下：
1 package servelet;
2
3 import java.io.IOException;
4 import java.io.UnsupportedEncodingException;
5 import java.sql.Connection;
6 import java.sql.PreparedStatement;
7 import java.sql.ResultSet;
8 import java.sql.SQLException;
9 import java.sql.Statement;
10
11 import javax.servlet.ServletException;
12 import javax.servlet.annotation.WebServlet;
13 import javax.servlet.http.HttpServlet;
14 import javax.servlet.http.HttpServletRequest;
15 import javax.servlet.http.HttpServletResponse;
16 import javax.swing.JOptionPane;
17 import javax.swing.plaf.metal.MetalIconFactory.PaletteCloseIcon;
18
19 import com.jdbc.bean.Course;
20 import com.jdbc.dao.JdbcMain;
21 import com.jdbc.util.BaseConnection;
22
23 /**
24 * Servlet implementation class Manage
25 */
26 @WebServlet("/Manage")
27 public class Manage extends HttpServlet {
28 private static final long serialVersionUID = 1L;
29
30 /**
31 * @see HttpServlet#HttpServlet()
32 */
33 public Manage() {
34 super();
35 // TODO Auto-generated constructor stub
36 }
37
38 /**
39 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
40 */
41 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
42 // TODO Auto-generated method stub
43 response.getWriter().append("Served at: ").append(request.getContextPath());
44
45 request.setCharacterEncoding("UTF-8");
46 String method = request.getParameter("method");
47
48
49 if("add".equals(method)) //添加课程
50 {
51
52
53 try {
54 add(request,response);
55 } catch (SQLException e) {
56 // TODO 自动生成的 catch 块
57 e.printStackTrace();
58 }
59
60 }else if("delete".equals(method)) //通过课程名称查找并删除对应的课程（必须是具体的课程名称，否则就显示未找到该课程，也就无法删除）
61 {
62 delete(request,response);
63 }else
64
65 if("find".equals(method)) //查找课程信息
66 {
67 find(request,response);
68 }else
69
70 if("update".equals(method)) //通过课程名称进行查找，并对其进行修改（由于只能通过课程查找）
71 {
72 update(request,response);
73 }
74
75 }
76
77
78
79
80 private void update(HttpServletRequest request, HttpServletResponse response) {
81 // TODO 自动生成的方法存根
82 Course cour = new Course();
83
84 String name = request.getParameter("class");
85 String teacher = request.getParameter("teacher");
86 String place = request.getParameter("place");
87
88 cour.setClassname(name);
89 cour.setTeacher(teacher);
90 cour.setPlace(place);
91 String teachers = "王建民刘立嘉刘丹王辉杨子光";
92 String places = "一教二教三教基教";
93 String pl = place.substring(0, 2);
94
95 if(teachers.indexOf(teacher) != -1)
96 {
97 if(places.indexOf(pl) != -1)
98 {
99 int res=JOptionPane.showConfirmDialog(JOptionPane.getRootFrame(), "提示","是否进行修改",JOptionPane.YES_NO_OPTION);
100 if(res==JOptionPane.YES_OPTION)
101 {
102
103 if (JdbcMain.update(cour)==1) {
104
105 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "成功修改", "操作成功" + name, JOptionPane.INFORMATION_MESSAGE);
106 response.setHeader("refresh", "0;url=admin/main.jsp"); //点击“是”后执行这个代码块
107 return ;
108 }else {
109 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "操作错误", "请重新操作", JOptionPane.ERROR_MESSAGE);
110 response.setHeader("refresh", "0;url=admin/update.jsp");
111 return ;
112 }
113 }else
114 {
115 response.setHeader("refresh", "0;url=admin/main.jsp"); //点击“否”后执行这个代码块
116 return ;
117 }
118 }else
119 {
120 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "上课地点错误", "操作错误", JOptionPane.ERROR_MESSAGE);
121 response.setHeader("refresh", "0;url=admin/update.jsp");
122 return ;
123 }
124 }else {
125 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),"没有这名教师" ,"操作错误",JOptionPane.ERROR_MESSAGE);
126 response.setHeader("refresh", "0;url=admin/update.jsp");
127 return ;
128 }
129
130
131 }
132
133 private void find(HttpServletRequest request, HttpServletResponse response) throws UnsupportedEncodingException {
134 // TODO 自动生成的方法存根
135 request.setCharacterEncoding("UTF-8");
136
137 Course cour = new Course();
138 cour = JdbcMain.find(request.getParameter("class"));
139 if (cour.getClassname() == null) {
140 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "未找到相应信息", "操作错误", JOptionPane.ERROR_MESSAGE);
141 response.setHeader("refresh", "0;url=admin/find.jsp");
142 }else {
143 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),"您要查找的是" + cour.getClassname() + cour.getTeacher() + cour.getPlace() , "操作成功", JOptionPane.INFORMATION_MESSAGE);
144 response.setHeader("refresh", "0;url=admin/main.jsp");
145 }
146
147
148
149 }
150
151 private void delete(HttpServletRequest request, HttpServletResponse response) throws UnsupportedEncodingException {
152 // TODO 自动生成的方法存根
153 request.setCharacterEncoding("UTF-8");
154 String classname = request.getParameter("class");
155 Course cour = new Course();
156 cour = null;
157 cour = JdbcMain.find(classname);
158 if(cour == null)
159 {
160 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "未找到此课程", "操作错误", JOptionPane.ERROR_MESSAGE);
161 response.setHeader("refresh", "0;url=admin/delete.jsp");
162 return ;
163 }
164
165 int res=JOptionPane.showConfirmDialog(JOptionPane.getRootFrame(), "请确认", "确认删除"+ cour.getClassname() + cour.getTeacher() + cour.getPlace(), JOptionPane.YES_NO_OPTION);
166 if(res == JOptionPane.YES_OPTION)
167 {
168 if(JdbcMain.delete(classname)==1)
169 {
170 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "操作成功", "成功删除" + cour.getClassname(), JOptionPane.INFORMATION_MESSAGE);
171 response.setHeader("refresh", "0;url=admin/main.jsp");
172 return ;
173 }else {
174 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "操作错误", "请重新操作", JOptionPane.ERROR_MESSAGE);
175 response.setHeader("refresh", "0;url=admin/delete.jsp");
176 return ;
177 }
178 }else {
179 response.setHeader("refresh", "0;url=admin/main.jsp");
180 return ;
181 }
182
183
184
185
186 }
187
188
189
190 private void add(HttpServletRequest request, HttpServletResponse response) throws IOException, SQLException {
191 // TODO 自动生成的方法存根
192 request.setCharacterEncoding("UTF-8");
193 Course cour = new Course();
194
195 String classname = request.getParameter("class");
196 String teacher = request.getParameter("teacher");
197 String place = request.getParameter("place");
198
199 cour.setClassname(classname);
200 cour.setTeacher(teacher);
201 cour.setPlace(place);
202
203
204 Connection con = BaseConnection.getConnection();
205 PreparedStatement ps = null;
206 ResultSet rs = null;
207 String sql = "select * from course";
208
209 try {
210 ps=con.prepareStatement(sql);
211 rs=ps.executeQuery();
212 while(rs.next()){
213 if(classname.equals(rs.getString("classname")))
214 {
215
216 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "课程名称重复", "操作错误", JOptionPane.ERROR_MESSAGE);
217 response.setHeader("refresh", "0;url=admin/add.jsp");
218
219 return;
220
221 }
222
223
224 }
225
226 } catch (SQLException e) {
227 // TODO 自动生成的 catch 块
228 e.printStackTrace();
229 }finally{
230 try{
231 if(ps!=null){
232 ps.close();
233 }if(con!=null){
234 con.close();
235 }if(rs!=null)
236 {
237 rs.close();
238 }
239 }catch(Exception e2){
240 e2.printStackTrace();
241 }
242 }
243
244
245 String teachers = "王建民刘立嘉刘丹王辉杨子光";
246 String places = "一教二教三教基教";
247 String pl = place.substring(0, 2);
248
249 if(teachers.indexOf(teacher) != -1)
250 {
251 if(places.indexOf(pl) != -1)
252 {
253 int res=JOptionPane.showConfirmDialog(JOptionPane.getRootFrame(), "您要添加的是：" + classname + teacher + place , "是否继续", JOptionPane.YES_NO_OPTION);
254 if(res==JOptionPane.YES_OPTION){
255 if (JdbcMain.add(cour) == 1) {
256
257 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "添加成功", "操作成功" + cour.getClassname(), JOptionPane.INFORMATION_MESSAGE);
258 response.setHeader("refresh", "0;url=admin/main.jsp");
259 return ;
260 }else
261 {
262 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "请重新操作", "操作错误", JOptionPane.ERROR_MESSAGE);
263 response.setHeader("refresh", "0;url=admin/add.jsp");
264 }
265 //点击“是”后执行这个代码块
266 }else{
267 System.out.println("选择否后执行的代码"); //点击“否”后执行这个代码块
268 return;
269 }
270
271
272 }else
273 {
274 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(), "上课地点错误", "操作错误", JOptionPane.ERROR_MESSAGE);
275 response.setHeader("refresh", "0;url=admin/add.jsp");
276 return ;
277 }
278 }else
279 {
280 JOptionPane.showMessageDialog(JOptionPane.getRootFrame(),"没有这名教师" ,"操作错误",JOptionPane.ERROR_MESSAGE);
281 response.setHeader("refresh", "0;url=admin/add.jsp");
282 return ;
283 }
284 }
285
286 /**
287 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
288 */
289 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
290 // TODO Auto-generated method stub
291 doGet(request, response);
292 }
293
294 }
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原文地址：https://www.cnblogs.com/1gaoyu/p/10087128.html
时间： 2024-08-18 17:51:43