java web课程管理系统开发实例（从数据库连接到代码）
以下是几个简单知识：
JavaBean：用于传递数据，拥有与数据相关的逻辑处理
JSP：从Model接收数据并生成HTML
Servlet：接收HTTP请求并控制Model和View
jdbc：用于配置环境
前言：相关的软件下载和环境配置
1、下载并配置JDK。
2、下载eclipse。
3、下载并配置apache-tomcat（服务器）。
4、下载MySQL（数据库）。
5、下载Navicat for MySQL（数据库可视化工具），方便对数据库的操作。
6、下载jdbc用来实现eclipse中的项目与数据库实现连接。
（看网上教程就好）
一、【建立数据库】
库中设有课程，教师，教室三个值
二、【新建web项目】
打开eclipse，点击File—》New—》other—》Dynamic Web Project
点击Next
需要输入项目名，最好用英文填写，完成之后eclipse左侧会有刚刚创建的项目出现下图
在我的电脑中，打开你下载的jdbc（也就是mysql-connector-java-8.0.13）所在的文件夹中的
将mysql-connector-java-8.0.13文件复制
粘贴在eclipse中，你所建立的项目下的 WebContent/WEB-INF/lib 文件夹下，如下图
接下来便是jsp文件和java文件的写入了.
代码如下：
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 </style> 19 </head> 20 <body> 21 <% 22 Object message = request.getAttribute("message"); 23 if(message!=null && !"".equals(message)){ 24 25 %> 26 <script type="text/javascript"> 27 alert("<%=request.getAttribute("message")%>"); 28 </script> 29 <%} %> 30 <div align="center"> 31 <h1 style="color: red;">课程信息录入</h1> 32 <a href="index.jsp">返回主页</a> 33 <form action="CourseServlet?method=add" method="post" onsubmit="return check()"> 34 <div class="a"> 35 课程名称<input type="text" id="name" name="name"/> 36 </div> 37 <div class="a"> 38 任课教师<input type="text" id="teacher" name="teacher" /> 39 </div> 40 <div class="a"> 41 上课地点<input type="text" id="classroom" name="classroom" /> 42 </div> 43 <div class="a"> 44 <button type="submit" class="b">保 存</button> 45 </div> 46 </form> 47 </div> 48 <script type="text/javascript"> 49 function check() { 50 var name = document.getElementById("name");; 51 var teacher = document.getElementById("teacher"); 52 var classroom = document.getElementById("classroom"); 53 54 //非空 55 if(name.value == '') { 56 alert('课程名称为空'); 57 name.focus(); 58 return false; 59 } 60 if(teacher.value == '') { 61 alert('教师为空'); 62 teacher.focus(); 63 return false; 64 } 65 if(classroom.value == '') { 66 alert('上课地点为空'); 67 classroom.focus(); 68 return false; 69 } 70 71 //教师 72 if(teacher.value != '王建民' && teacher.value != '王辉' && teacher.value != '刘丹' && teacher.value != '刘立嘉' && teacher.value != '杨子光'){ 73 alert('教师名称错误'); 74 return false; 75 } 76 77 //教室 78 if(!/^基教/.test(classroom.value) && !/^一教/.test(classroom.value) && !/^二教/.test(classroom.value) && !/^三教/.test(classroom.value)) { 79 alert('上课地点错误'); 80 return false; 81 } 82 } 83 </script> 84 </body> 85 </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 </style> 19 </head> 20 <body> 21 <% 22 Object message = request.getAttribute("message"); 23 if(message!=null && !"".equals(message)){ 24 25 %> 26 <script type="text/javascript"> 27 alert("<%=request.getAttribute("message")%>"); 28 </script> 29 <%} %> 30 <div align="center"> 31 <h1 style="color: red;">课程信息删除</h1> 32 <a href="index.jsp">返回主页</a> 33 <form action="CourseServlet?method=getcoursebyname" method="post" onsubmit="return check()"> 34 <div class="a"> 35 课程名称<input type="text" id="name" name="name"/> 36 </div> 37 <div class="a"> 38 <button type="submit" class="b">查 找</button> 39 </div> 40 </form> 41 </div> 42 <script type="text/javascript"> 43 function check() { 44 var name = document.getElementById("name");; 45 46 //非空 47 if(name.value == '') { 48 alert('课程名称为空'); 49 name.focus(); 50 return false; 51 } 52 } 53 </script> 54 </body> 55 </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: red;">课程信息删除</h1> 27 <a href="index.jsp">返回主页</a> 28 <table class="tb"> 29 <tr> 30 <td>课程名称</td> 31 <td>${course.name}</td> 32 </tr> 33 <tr> 34 <td>任课教师</td> 35 <td>${course.teacher}</td> 36 </tr> 37 <tr> 38 <td>上课地点</td> 39 <td>${course.classroom}</td> 40 </tr> 41 </table> 42 <div class="a"> 43 <a onclick="return check()" href="CourseServlet?method=del&id=${course.id}">删 除</a> 44 </div> 45 </div> 46 <script type="text/javascript"> 47 function check() { 48 if (confirm("真的要删除吗？")){ 49 return true; 50 }else{ 51 return false; 52 } 53 } 54 </script> 55 </body> 56 </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 </style> 19 </head> 20 <body> 21 <% 22 Object message = request.getAttribute("message"); 23 if(message!=null && !"".equals(message)){ 24 25 %> 26 <script type="text/javascript"> 27 alert("<%=request.getAttribute("message")%>"); 28 </script> 29 <%} %> 30 <div align="center"> 31 <h1 style="color: red;">课程信息修改</h1> 32 <a href="index.jsp">返回主页</a> 33 <form action="CourseServlet?method=update" method="post" onsubmit="return check()"> 34 <div class="a"> 35 课程名称<input type="text" id="name" name="name" value="${course.name}"/> 36 </div> 37 <div class="a"> 38 任课教师<input type="text" id="teacher" name="teacher" value="${course.teacher}"/> 39 </div> 40 <div class="a"> 41 上课地点<input type="text" id="classroom" name="classroom" value="${course.classroom}"/> 42 </div> 43 <input type="hidden" id="id" name="id" value="${course.id}"/> 44 <div class="a"> 45 <button type="submit" class="b">修 改</button> 46 </div> 47 </form> 48 </div> 49 <script type="text/javascript"> 50 function check() { 51 var name = document.getElementById("name");; 52 var teacher = document.getElementById("teacher"); 53 var classroom = document.getElementById("classroom"); 54 55 //非空 56 if(name.value == '') { 57 alert('课程名称为空'); 58 name.focus(); 59 return false; 60 } 61 if(teacher.value == '') { 62 alert('教师为空'); 63 teacher.focus(); 64 return false; 65 } 66 if(classroom.value == '') { 67 alert('上课地点为空'); 68 classroom.focus(); 69 return false; 70 } 71 72 //教师 73 if(teacher.value != '王建民' && teacher.value != '王辉' && teacher.value != '刘丹' && teacher.value != '刘立嘉' && teacher.value != '杨子光'){ 74 alert('教师名称错误'); 75 return false; 76 } 77 78 //教室 79 if(!/^基教/.test(classroom.value) && !/^一教/.test(classroom.value) && !/^二教/.test(classroom.value) && !/^三教/.test(classroom.value)) { 80 alert('上课地点错误'); 81 return false; 82 } 83 } 84 </script> 85 </body> 86 </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>首页</title> 8 <style> 9 .a{ 10 font-size: 26px; 11 margin-top: 20px; 12 } 13 </style> 14 </head> 15 <body> 16 <div align="center"> 17 <h1 style="color: red;">课程基本信息管理系统</h1> 18 <div class="a"> 19 <a href="add.jsp">课程信息录入</a> 20 </div> 21 <div class="a"> 22 <a href="CourseServlet?method=list">课程信息修改</a> 23 </div> 24 <div class="a"> 25 <a href="del.jsp">课程信息删除</a> 26 </div> 27 <div class="a"> 28 <a href="search.jsp">课程信息查询</a> 29 </div> 30 </div> 31 </body> 32 </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 <style> 10 .a{ 11 margin-top: 20px; 12 } 13 .b{ 14 font-size: 20px; 15 width: 160px; 16 color: white; 17 background-color: greenyellow; 18 } 19 .tb, td { 20 border: 1px solid black; 21 font-size: 22px; 22 } 23 </style> 24 </head> 25 <body> 26 <% 27 Object message = request.getAttribute("message"); 28 if(message!=null && !"".equals(message)){ 29 30 %> 31 <script type="text/javascript"> 32 alert("<%=request.getAttribute("message")%>"); 33 </script> 34 <%} %> 35 <div align="center"> 36 <h1 style="color: red;">课程信息列表</h1> 37 <a href="index.jsp">返回主页</a> 38 <table class="tb"> 39 <tr> 40 <td>id</td> 41 <td>课程名称</td> 42 <td>任课教师</td> 43 <td>上课地点</td> 44 <td align="center" colspan="2">操作</td> 45 </tr> 46 <c:forEach items="${courses}" var="item"> 47 <tr> 48 <td>${item.id}</td> 49 <td>${item.name}</td> 50 <td>${item.teacher}</td> 51 <td>${item.classroom}</td> 52 <td><a href="CourseServlet?method=getcoursebyid&id=${item.id}">修改</a></td> 53 </tr> 54 </c:forEach> 55 </table> 56 </div> 57 </body> 58 </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 </style> 19 </head> 20 <body> 21 <div align="center"> 22 <h1 style="color: red;">课程信息查询</h1> 23 <a href="index.jsp">返回主页</a> 24 <form action="CourseServlet?method=search" method="post" onsubmit="return check()"> 25 <div class="a"> 26 课程名称<input type="text" id="name" name="name"/> 27 </div> 28 <div class="a"> 29 任课教师<input type="text" id="teacher" name="teacher" /> 30 </div> 31 <div class="a"> 32 上课地点<input type="text" id="classroom" name="classroom" /> 33 </div> 34 <div class="a"> 35 <button type="submit" class="b">查 询</button> 36 </div> 37 </form> 38 </div> 39 <script type="text/javascript"> 40 function check() { 41 var name = document.getElementById("name");; 42 var teacher = document.getElementById("teacher"); 43 var classroom = document.getElementById("classroom"); 44 45 //非空 46 if(name.value == '' && teacher.value == '' && classroom.value == '') { 47 alert('请填写一个条件'); 48 return false; 49 } 50 } 51 </script> 52 </body> 53 </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 <style> 10 .a{ 11 margin-top: 20px; 12 } 13 .b{ 14 font-size: 20px; 15 width: 160px; 16 color: white; 17 background-color: greenyellow; 18 } 19 .tb, td { 20 border: 1px solid black; 21 font-size: 22px; 22 } 23 </style> 24 </head> 25 <body> 26 <div align="center"> 27 <h1 style="color: red;">课程信息列表</h1> 28 <a href="index.jsp">返回主页</a> 29 <table class="tb"> 30 <tr> 31 <td>id</td> 32 <td>课程名称</td> 33 <td>任课教师</td> 34 <td>上课地点</td> 35 </tr> 36 <!-- forEach遍历出adminBeans --> 37 <c:forEach items="${courses}" var="item" varStatus="status"> 38 <tr> 39 <td>${item.id}</td> 40 <td><a>${item.name}</a></td> 41 <td>${item.teacher}</td> 42 <td>${item.classroom}</td> 43 </tr> 44 </c:forEach> 45 </table> 46 </div> 47 </body> 48 </html>
直接在上图中一起建立包和类
1 package com.hjf; 2 3 public class Course { 4 5 private int id; 6 private String name; 7 private String teacher; 8 private String classroom; 9 10 public int getId() { 11 return id; 12 } 13 public void setId(int id) { 14 this.id = id; 15 } 16 public String getName() { 17 return name; 18 } 19 public void setName(String name) { 20 this.name = name; 21 } 22 public String getTeacher() { 23 return teacher; 24 } 25 public void setTeacher(String teacher) { 26 this.teacher = teacher; 27 } 28 public String getClassroom() { 29 return classroom; 30 } 31 public void setClassroom(String classroom) { 32 this.classroom = classroom; 33 } 34 35 public Course() {} 36 37 public Course(int id, String name, String teacher, String classroom) { 38 this.id = id; 39 this.name = name; 40 this.teacher = teacher; 41 this.classroom = classroom; 42 } 43 44 public Course(String name, String teacher, String classroom) { 45 this.name = name; 46 this.teacher = teacher; 47 this.classroom = classroom; 48 } 49 }
1 package com.hjf; 2 3 import java.sql.Connection; 4 5 import java.sql.ResultSet; 6 import java.sql.SQLException; 7 import java.sql.Statement; 8 import java.util.ArrayList; 9 import java.util.List; 10 11 12 13 /** 14 * 课程Dao 15 * Dao层操作数据 16 * @author Hu 17 * 18 */ 19 public class CourseDao { 20 21 /** 22 * 添加 23 * @param course 24 * @return 25 */ 26 public boolean add(Course course) { 27 String sql = "insert into course(name, teacher, classroom) values('" + course.getName() + "','" + course.getTeacher() + "','" + course.getClassroom() + "')"; 28 Connection conn = DBUtil.getConn(); 29 Statement state = null; 30 boolean f = false; 31 int a = 0; 32 33 try { 34 state = conn.createStatement(); 35 state.executeUpdate(sql); 36 } catch (Exception e) { 37 e.printStackTrace(); 38 } finally { 39 DBUtil.close(state, conn); 40 } 41 42 if (a > 0) { 43 f = true; 44 } 45 return f; 46 } 47 48 /** 49 * 删除 50 * 51 * @param id 52 * @return 53 */ 54 public boolean delete (int id) { 55 boolean f = false; 56 String sql = "delete from course where id='" + id + "'"; 57 Connection conn = DBUtil.getConn(); 58 Statement state = null; 59 int a = 0; 60 61 try { 62 state = conn.createStatement(); 63 a = state.executeUpdate(sql); 64 } catch (SQLException e) { 65 e.printStackTrace(); 66 } finally { 67 DBUtil.close(state, conn); 68 } 69 70 if (a > 0) { 71 f = true; 72 } 73 return f; 74 } 75 76 /** 77 * 修改 78 * @param name 79 * @param pass 80 */ 81 public boolean update(Course course) { 82 String sql = "update course set name='" + course.getName() + "', teacher='" + course.getTeacher() + "', classroom='" + course.getClassroom() 83 + "' where id='" + course.getId() + "'"; 84 Connection conn = DBUtil.getConn(); 85 Statement state = null; 86 boolean f = false; 87 int a = 0; 88 89 try { 90 state = conn.createStatement(); 91 a = state.executeUpdate(sql); 92 } catch (SQLException e) { 93 e.printStackTrace(); 94 } finally { 95 DBUtil.close(state, conn); 96 } 97 98 if (a > 0) { 99 f = true; 100 } 101 return f; 102 } 103 104 /** 105 * 验证课程名称是否唯一 106 * true --- 不唯一 107 * @param name 108 * @return 109 */ 110 public boolean name(String name) { 111 boolean flag = false; 112 String sql = "select name from course where name = '" + name + "'"; 113 Connection conn = DBUtil.getConn(); 114 Statement state = null; 115 ResultSet rs = null; 116 117 try { 118 state = conn.createStatement(); 119 rs = state.executeQuery(sql); 120 while (rs.next()) { 121 flag = true; 122 } 123 } catch (SQLException e) { 124 e.printStackTrace(); 125 } finally { 126 DBUtil.close(rs, state, conn); 127 } 128 return flag; 129 } 130 131 /** 132 * 通过ID得到类 133 * @param id 134 * @return 135 */ 136 public Course getCourseById(int id) { 137 String sql = "select * from course where id ='" + id + "'"; 138 Connection conn = DBUtil.getConn(); 139 Statement state = null; 140 ResultSet rs = null; 141 Course course = null; 142 143 try { 144 state = conn.createStatement(); 145 rs = state.executeQuery(sql); 146 while (rs.next()) { 147 String name = rs.getString("name"); 148 String teacher = rs.getString("teacher"); 149 String classroom = rs.getString("classroom"); 150 course = new Course(id, name, teacher, classroom); 151 } 152 } catch (Exception e) { 153 e.printStackTrace(); 154 } finally { 155 DBUtil.close(rs, state, conn); 156 } 157 158 return course; 159 } 160 161 /** 162 * 通过name得到Course 163 * @param name 164 * @return 165 */ 166 public Course getCourseByName(String name) { 167 String sql = "select * from course where name ='" + name + "'"; 168 Connection conn = DBUtil.getConn(); 169 Statement state = null; 170 ResultSet rs = null; 171 Course course = null; 172 173 try { 174 state = conn.createStatement(); 175 rs = state.executeQuery(sql); 176 while (rs.next()) { 177 int id = rs.getInt("id"); 178 String teacher = rs.getString("teacher"); 179 String classroom = rs.getString("classroom"); 180 course = new Course(id, name, teacher, classroom); 181 } 182 } catch (Exception e) { 183 e.printStackTrace(); 184 } finally { 185 DBUtil.close(rs, state, conn); 186 } 187 188 return course; 189 } 190 191 /** 192 * 查找 193 * @param name 194 * @param teacher 195 * @param classroom 196 * @return 197 */ 198 public List<Course> search(String name, String teacher, String classroom) { 199 String sql = "select * from course where "; 200 if (name != "") { 201 sql += "name like '%" + name + "%'"; 202 } 203 if (teacher != "") { 204 sql += "teacher like '%" + teacher + "%'"; 205 } 206 if (classroom != "") { 207 sql += "classroom like '%" + classroom + "%'"; 208 } 209 List<Course> list = new ArrayList<>(); 210 Connection conn = DBUtil.getConn(); 211 Statement state = null; 212 ResultSet rs = null; 213 214 try { 215 state = conn.createStatement(); 216 rs = state.executeQuery(sql); 217 Course bean = null; 218 while (rs.next()) { 219 int id = rs.getInt("id"); 220 String name2 = rs.getString("name"); 221 String teacher2 = rs.getString("teacher"); 222 String classroom2 = rs.getString("classroom"); 223 bean = new Course(id, name2, teacher2, classroom2); 224 list.add(bean); 225 } 226 } catch (SQLException e) { 227 e.printStackTrace(); 228 } finally { 229 DBUtil.close(rs, state, conn); 230 } 231 232 return list; 233 } 234 235 /** 236 * 全部数据 237 * @param name 238 * @param teacher 239 * @param classroom 240 * @return 241 */ 242 public List<Course> list() { 243 String sql = "select * from course"; 244 List<Course> list = new ArrayList<>(); 245 Connection conn = DBUtil.getConn(); 246 Statement state = null; 247 ResultSet rs = null; 248 249 try { 250 state = conn.createStatement(); 251 rs = state.executeQuery(sql); 252 Course bean = null; 253 while (rs.next()) { 254 int id = rs.getInt("id"); 255 String name2 = rs.getString("name"); 256 String teacher2 = rs.getString("teacher"); 257 String classroom2 = rs.getString("classroom"); 258 bean = new Course(id, name2, teacher2, classroom2); 259 list.add(bean); 260 } 261 } catch (SQLException e) { 262 e.printStackTrace(); 263 } finally { 264 DBUtil.close(rs, state, conn); 265 } 266 267 return list; 268 } 269 270 }
1 package com.hjf; 2 3 import java.util.List; 4 5 /** 6 * CourseService 7 * 服务层 8 * @author Hu 9 * 10 */ 11 public class CourseService { 12 13 CourseDao cDao = new CourseDao(); 14 15 /** 16 * 添加 17 * @param course 18 * @return 19 */ 20 public boolean add(Course course) { 21 boolean f = false; 22 if(!cDao.name(course.getName())) { 23 cDao.add(course); 24 f = true; 25 } 26 return f; 27 } 28 29 /** 30 * 删除 31 */ 32 public void del(int id) { 33 cDao.delete(id); 34 } 35 36 /** 37 * 修改 38 * @return 39 */ 40 public void update(Course course) { 41 cDao.update(course); 42 } 43 44 /** 45 * 通过ID得到一个Course 46 * @return 47 */ 48 public Course getCourseById(int id) { 49 return cDao.getCourseById(id); 50 } 51 52 /** 53 * 通过Name得到一个Course 54 * @return 55 */ 56 public Course getCourseByName(String name) { 57 return cDao.getCourseByName(name); 58 } 59 60 /** 61 * 查找 62 * @return 63 */ 64 public List<Course> search(String name, String teacher, String classroom) { 65 return cDao.search(name, teacher, classroom); 66 } 67 68 /** 69 * 全部数据 70 * @return 71 */ 72 public List<Course> list() { 73 return cDao.list(); 74 } 75 }
1 package com.hjf; 2 3 import java.io.IOException; 4 5 6 import java.util.List; 7 8 import javax.servlet.ServletException; 9 import javax.servlet.annotation.WebServlet; 10 import javax.servlet.http.HttpServlet; 11 import javax.servlet.http.HttpServletRequest; 12 import javax.servlet.http.HttpServletResponse; 13 14 @WebServlet("/CourseServlet") 15 public class CourseServlet extends HttpServlet { 16 17 private static final long serialVersionUID = 1L; 18 19 CourseService service = new CourseService(); 20 21 /** 22 * 方法选择 23 */ 24 protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 25 req.setCharacterEncoding("utf-8"); 26 String method = req.getParameter("method"); 27 if ("add".equals(method)) { 28 add(req, resp); 29 } else if ("del".equals(method)) { 30 del(req, resp); 31 } else if ("update".equals(method)) { 32 update(req, resp); 33 } else if ("search".equals(method)) { 34 search(req, resp); 35 } else if ("getcoursebyid".equals(method)) { 36 getCourseById(req, resp); 37 } else if ("getcoursebyname".equals(method)) { 38 getCourseByName(req, resp); 39 } else if ("list".equals(method)) { 40 list(req, resp); 41 } 42 } 43 44 /** 45 * 添加 46 * @param req 47 * @param resp 48 * @throws IOException 49 * @throws ServletException 50 */ 51 private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException { 52 req.setCharacterEncoding("utf-8"); 53 String name = req.getParameter("name"); 54 String teacher = req.getParameter("teacher"); 55 String classroom = req.getParameter("classroom"); 56 Course course = new Course(name, teacher, classroom); 57 58 //添加后消息显示 59 if(service.add(course)) { 60 req.setAttribute("message", "添加成功"); 61 req.getRequestDispatcher("add.jsp").forward(req,resp); 62 } else { 63 req.setAttribute("message", "课程名称重复，请重新录入"); 64 req.getRequestDispatcher("add.jsp").forward(req,resp); 65 } 66 } 67 68 /** 69 * 全部 70 * @param req 71 * @param resp 72 * @throws ServletException 73 */ 74 private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 75 req.setCharacterEncoding("utf-8"); 76 List<Course> courses = service.list(); 77 req.setAttribute("courses", courses); 78 req.getRequestDispatcher("list.jsp").forward(req,resp); 79 } 80 81 /** 82 * 通过ID得到Course 83 * @param req 84 * @param resp 85 * @throws ServletException 86 */ 87 private void getCourseById(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 88 req.setCharacterEncoding("utf-8"); 89 int id = Integer.parseInt(req.getParameter("id")); 90 Course course = service.getCourseById(id); 91 req.setAttribute("course", course); 92 req.getRequestDispatcher("detail2.jsp").forward(req,resp); 93 } 94 95 /** 96 * 通过名字查找 97 * 跳转至删除 98 * @param req 99 * @param resp 100 * @throws IOException 101 * @throws ServletException 102 */ 103 private void getCourseByName(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 104 req.setCharacterEncoding("utf-8"); 105 String name = req.getParameter("name"); 106 Course course = service.getCourseByName(name); 107 if(course == null) { 108 req.setAttribute("message", "查无此课程！"); 109 req.getRequestDispatcher("del.jsp").forward(req,resp); 110 } else { 111 req.setAttribute("course", course); 112 req.getRequestDispatcher("detail.jsp").forward(req,resp); 113 } 114 } 115 116 /** 117 * 删除 118 * @param req 119 * @param resp 120 * @throws IOException 121 * @throws ServletException 122 */ 123 private void del(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 124 req.setCharacterEncoding("utf-8"); 125 int id = Integer.parseInt(req.getParameter("id")); 126 service.del(id); 127 req.setAttribute("message", "删除成功！"); 128 req.getRequestDispatcher("del.jsp").forward(req,resp); 129 } 130 131 /** 132 * 修改 133 * @param req 134 * @param resp 135 * @throws IOException 136 * @throws ServletException 137 */ 138 private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 139 req.setCharacterEncoding("utf-8"); 140 int id = Integer.parseInt(req.getParameter("id")); 141 String name = req.getParameter("name"); 142 String teacher = req.getParameter("teacher"); 143 String classroom = req.getParameter("classroom"); 144 Course course = new Course(id, name, teacher, classroom); 145 146 service.update(course); 147 req.setAttribute("message", "修改成功"); 148 req.getRequestDispatcher("CourseServlet?method=list").forward(req,resp); 149 } 150 151 /** 152 * 查找 153 * @param req 154 * @param resp 155 * @throws ServletException 156 */ 157 private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 158 req.setCharacterEncoding("utf-8"); 159 String name = req.getParameter("name"); 160 String teacher = req.getParameter("teacher"); 161 String classroom = req.getParameter("classroom"); 162 List<Course> courses = service.search(name, teacher, classroom); 163 req.setAttribute("courses", courses); 164 req.getRequestDispatcher("searchlist.jsp").forward(req,resp); 165 } 166 }
1 package com.hjf; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.ResultSet; 6 import java.sql.SQLException; 7 import java.sql.Statement; 8 9 /** 10 * 数据库连接工具 11 * @author Hu 12 * 13 */ 14 public class DBUtil { 15 16 public static String db_url = "jdbc:mysql://localhost:3306/course?useSSL=false&useUnicode=true&characterEncoding=UTF-8"; 17 public static String db_user = "root"; 18 public static String db_pass = "123"; 19 20 public static Connection getConn () { 21 Connection conn = null; 22 23 try { 24 Class.forName("com.mysql.jdbc.Driver");//加载驱动 25 conn = DriverManager.getConnection(db_url, db_user, db_pass); 26 } catch (Exception e) { 27 e.printStackTrace(); 28 } 29 30 return conn; 31 } 32 33 /** 34 * 关闭连接 35 * @param state 36 * @param conn 37 */ 38 public static void close (Statement state, Connection conn) { 39 if (state != null) { 40 try { 41 state.close(); 42 } catch (SQLException e) { 43 e.printStackTrace(); 44 } 45 } 46 47 if (conn != null) { 48 try { 49 conn.close(); 50 } catch (SQLException e) { 51 e.printStackTrace(); 52 } 53 } 54 } 55 56 public static void close (ResultSet rs, Statement state, Connection conn) { 57 if (rs != null) { 58 try { 59 rs.close(); 60 } catch (SQLException e) { 61 e.printStackTrace(); 62 } 63 } 64 65 if (state != null) { 66 try { 67 state.close(); 68 } catch (SQLException e) { 69 e.printStackTrace(); 70 } 71 } 72 73 if (conn != null) { 74 try { 75 conn.close(); 76 } catch (SQLException e) { 77 e.printStackTrace(); 78 } 79 } 80 } 81 82 }
关于为什么有的类需要单独一个包
为了不同项目间更好的对接.
附：
目录说明
com.astar
- config 用于放置配置文件，资源文件等。如Spring配置文件applicationContext.xml
- background 后台管理层结构
- common 项目中公用的文件，如下
- constant 常量
- enumeration 枚举类
- util 工具类
- dao 抽象接口及实现类，用于放置封装好的底层数据访问操作。如JPA的CURD
- service 抽象业务接口及实现类，用于调用同层dao目录中的DAO对象，便于被实现和继承
- controller 控制层，通过SpringMVC 实现请求处理，并转发。
- entity 实体层，用于放置项目中的公用实体
- filter 过滤层，放置过滤器
- center/finance/printer/keeper/editor 这是项目中的角色，每个角色作为一个独立层，便于分工和解耦，使每层中的业务功能内聚
- service 独立的，特有的业务
- dao 通过该层自己来处理DAO
