一、题目：WEB界面链接数据库
1.考试要求：
1登录账号：要求由6到12位字母、数字、下划线组成，只有字母可以开头；（1分）
2登录密码：要求显示“• ”或“*”表示输入位数，密码要求八位以上字母、数字组成。（1分）
3性别：要求用单选框或下拉框实现，选项只有“男”或“女”；（1分）
4学号：要求八位数字组成，前四位为“2018”开头，输入自己学号；（1分）
5姓名：输入自己的姓名；
5电子邮箱：要求判断正确格式xxxx@xxxx.xxxx；（1分）
6点击“添加”按钮，将学生个人信息存储到数据库中。（3分）
7可以演示连接上数据库。（2分）
二、设计思路：
1、首先在users.jsp代码中，用HTML写一个添加表单即可
2、在DBUtil.java文件编写中对数据库进行连接和关闭的操作
3、在Dao.java文件中编写向数据库中插入数据的SQL语句，以及判断Servelet.java中传递的数据是否为空。
4、在 users.jsp 文件中对表单用javascript进行form表单校验，将满足所有添加要求的数据传入Servelet.java中，用post方式传递。
5、在Selvlet.java 文件调用DBUtil.java文件和Dao.java文件，得到Dao.java中判断Servelet.java中传递的数据是否为空的函数，并进行二次表单校验。
6、Servelet.java中若数据合理，调用DBUtil.java的方法，连接数据库将数据通过参数的形式传递给在Dao.java文件中向数据库中插入数据的SQL语句，将数据添加到数据库。若添加成功，给出提示信息并返回users.jsp代码中action跳转的Servlet?method=add页面。若添加失败，给出提示信息并返回users.jsp代码中action跳转的Servlet?method=add页面。
三、源代码
1、Dao.java文件
1 package Dao; 2
3 import java.sql.Connection; 4 import java.sql.Statement; 5
6 import DBUtil.DBUtil; 7
8 import Entity.User; 9
10 public class Dao { 11
12 public boolean add(User user) { 13 //将数据插入数据库的SQL语句
14 String sql = "insert into uses1 (username,password,sex,name,stuname,email,xueyuan,xi,banji,year,address,addtext) values('"+ user.getUsername() + "','"+ user.getPassword() +"','"+ user.getSex() +"','"+user.getName() +"','"+ user.getStuname() +"','"+user.getEmail()+"','"+ user.getXueyuan() +"','"+user.getXi()+"','"+user.getBanji()+"','"+user.getYear()+"','"+user.getAddress()+"','"+user.getAddtext()+"')"; 15 // 创建数据库链接
16 Connection conn = DBUtil.getConn(); 17 Statement state = null; 18 boolean f = false; 19 int a = 0; 20
21 try { 22 state = conn.createStatement(); 23 a=state.executeUpdate(sql); 24 } catch (Exception e) { 25 e.printStackTrace(); 26 } finally { 27 // 关闭z 连接
28 DBUtil.close(state, conn); 29 } 30
31 if (a > 0) { 32 f = true; 33 } 34 return f; 35
36 } 37
38
39 }
2、DBUtil.java文件
1 package DBUtil; 2
3
4
5 import java.sql.Connection; 6 import java.sql.DriverManager; 7 import java.sql.PreparedStatement; 8 import java.sql.ResultSet; 9 import java.sql.SQLException; 10 import java.sql.Statement; 11
12 /**
13 * @author Hu 14 * 15 */
16 public class DBUtil { 17
18 public static String db_url = "jdbc:mysql://localhost:3306/user?serverTimezone=UTC";//登录数据库
19 public static String db_user = "root"; 20 public static String db_pass = "123"; 21
22 public static Connection getConn () { 23 Connection conn = null; 24
25 try { 26 Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动
27 conn = DriverManager.getConnection(db_url, db_user, db_pass); 28 } catch (Exception e) { 29 e.printStackTrace(); 30 } 31
32 return conn; 33 } 34 /**
35 * 关闭与数据库的连接 36 * @param state 37 * @param conn 38 */
39 public static void close (Statement state, Connection conn) { 40 if (state != null) { 41 try { 42 state.close(); 43 } catch (SQLException e) { 44 e.printStackTrace(); 45 } 46 } 47
48 if (conn != null) { 49 try { 50 conn.close(); 51 } catch (SQLException e) { 52 e.printStackTrace(); 53 } 54 } 55 } 56
57 public static void close (ResultSet rs, Statement state, Connection conn) { 58 if (rs != null) { 59 try { 60 rs.close(); 61 } catch (SQLException e) { 62 e.printStackTrace(); 63 } 64 } 65
66 if (state != null) { 67 try { 68 state.close(); 69 } catch (SQLException e) { 70 e.printStackTrace(); 71 } 72 } 73
74 if (conn != null) { 75 try { 76 conn.close(); 77 } catch (SQLException e) { 78 e.printStackTrace(); 79 } 80 } 81 } 82 public static void main(String[] args) throws SQLException { 83 Connection conn = getConn(); 84 PreparedStatement pstmt = null; 85 ResultSet rs = null; 86 String sql ="select * from users"; 87 pstmt = conn.prepareStatement(sql); 88 rs = pstmt.executeQuery(); 89 if(rs.next()){ 90 System.out.println("空"); 91 }else{ 92 System.out.println("不空"); 93 } 94 } 95 }
3、User.java(用户属性类)文件
1 package Entity; 2
3 public class User { 4
5 private String username; 6 private String password; 7 private String sex; 8 private String name; 9 private String stuname; 10 private String email; 11 private String xueyuan; 12 private String xi; 13 private String banji; 14 private String year; 15 private String address; 16 private String addtext; 17
18 public String getUsername() { 19 return username; 20 } 21
22 public void setUsername(String username) { 23 this.username = username; 24 } 25
26 public String getPassword() { 27 return password; 28 } 29
30 public void setPassword(String password) { 31 this.password = password; 32 } 33
34 public String getSex() { 35 return sex; 36 } 37
38 public void setSex(String sex) { 39 this.sex = sex; 40 } 41
42 public String getName() { 43 return name; 44 } 45
46 public void setName(String name) { 47 this.name = name; 48 } 49
50 public String getStuname() { 51 return stuname; 52 } 53
54 public void setStuname(String stuname) { 55 this.stuname = stuname; 56 } 57
58 public String getEmail() { 59 return email; 60 } 61
62 public void setEmail(String email) { 63 this.email = email; 64 } 65
66 public String getXueyuan() { 67 return xueyuan; 68 } 69
70 public void setXueyuan(String xueyuan) { 71 this.xueyuan = xueyuan; 72 } 73
74 public String getXi() { 75 return xi; 76 } 77
78 public void setXi(String xi) { 79 this.xi = xi; 80 } 81
82 public String getBanji() { 83 return banji; 84 } 85
86 public void setBanji(String banji) { 87 this.banji = banji; 88 } 89
90 public String getYear() { 91 return year; 92 } 93
94 public void setYear(String year) { 95 this.year = year; 96 } 97
98 public String getAddress() { 99 return address; 100 } 101
102 public void setAddress(String address) { 103 this.address = address; 104 } 105
106 public String getAddtext() { 107 return addtext; 108 } 109
110 public void setAddtext(String addtext) { 111 this.addtext = addtext; 112 } 113
114 public User() {} 115
116 public User(String username,String password,String sex,String name,String stuname,String email,String xueyuan, String xi,String banji,String year,String address,String addtext) { 117
118
119 this.username=username; 120 this.password=password; 121 this.sex=sex; 122 this.name=name; 123 this.stuname=stuname; 124 this.email=email; 125 this.xueyuan=xueyuan; 126 this.xi=xi; 127 this.banji=banji; 128 this.year=year; 129 this.address=address; 130 this.addtext=addtext; 131
132 } 133
134
135 }
4、Servlet.java文件
1 package Servlet; 2
3 import java.io.IOException; 4
5 import javax.servlet.ServletException; 6 import javax.servlet.annotation.WebServlet; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse; 10
11 import Dao.Dao; 12
13 import Entity.User; 14
15
16
17
18 @WebServlet("/Servlet") 19 public class Servlet extends HttpServlet { 20 private static final long serialVersionUID = 1L; 21
22
23 public Servlet() { 24 super(); 25
26 } 27 protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 28 req.setCharacterEncoding("utf-8"); 29 String method = req.getParameter("method"); 30 if ("add".equals(method)) { 31 add(req, resp); 32 } 33 } 34
35
36 public void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ 37 req.setCharacterEncoding("utf-8"); 38 String username = req.getParameter("username"); 39 String password = req.getParameter("password"); 40 String sex = req.getParameter("sex"); 41 String name = req.getParameter("name"); 42 String stuname = req.getParameter("stuname"); 43 String email = req.getParameter("email"); 44 String xueyuan = req.getParameter("xueyuan"); 45 String xi= req.getParameter("xi"); 46 String banji= req.getParameter("banji"); 47 String year= req.getParameter("year"); 48 String address= req.getParameter("address"); 49 String addtext= req.getParameter("addtext"); 50 //调用用户属性类
51 User user = new User(username,password,sex,name,stuname,email,xueyuan,xi,banji,year,address,addtext); 52 //接受判断函数返回值
53 Dao dao =new Dao(); 54 boolean f=dao.add(user); 55 //提示信息
56 if(f) { 57 req.setAttribute("message", "注册成功！"); 58 req.getRequestDispatcher("users.jsp").forward(req,resp); 59 } 60 else { 61 req.setAttribute("message", "已有账号，重复登录！"); 62 req.getRequestDispatcher("users.jsp").forward(req,resp); 63 } 64 } 65 }
5、users.jsp文件
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 <script>
9 //表单校验
10 function check() { 11 flag=0; 12 var rep = /^[\w\u4e00-\u9fa5]{6,8}$/; //判断字符串是否为数字和字母组合
13 var myPattern = new RegExp("^[a-zA-Z]"); // 以英文字母开头
14 var username = document.getElementById("username").value; 15 //alert(username.length);
16 if(!(username.length>5&&username.length<13)){ 17 alert("用户名长度错误！");return false; 18 } 19 else if(!(rep.test(username))){ 20 alert("用户名组成内容错误！");return false; 21 }else if(!(myPattern.exec(username))){ 22 alert("用户名开头必须是字母！");return false; 23 } 24 var password = document.getElementById("password").value; 25 if(password.length<8){ 26 alert("密码长度错误"); 27 return false; 28 } 29
30 var stuname = document.getElementById("stuname").value; 31 if(stuname.length!=8){ 32 alert("学号长度错误！"); 33 return false; 34 } 35 if(stuname [0]=='2'&&stuname[1]=='0'&&stuname[2]=='1'&&stuname[3]=='8'){ 36 flag++; 37 } 38 else{ 39 alert("学号格式错误！"); 40 return false; 41 } 42
43 var email = document.getElementById("email").value; 44 if(/^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+/.test(email)){ 45 flag++; 46 } 47 else{ 48 alert("邮箱格式错误！"); 49 return false; 50 } 51 //标志法判断是否添加成功
52 if(flag>1){ 53 alert("添加成功"); 54 return true; 55 } 56 else{ 57 alert("添加失败"); 58 return false; 59 } 60 } 61 </script>
62 </head>
63
64 <body>
65
66
67
68 <table border="0px" cellpadding="10px" cellspacing="0px"
69 style="width: 50%;margin:auto;background:rgb(195,195,195)" bordercolor="red" >
70 <form action="Servlet?method=add" method="post"
71 onsubmit="return check()">
72 <caption>当前位置：添加学生信息</caption>
73
74
75 <tr>
76 <td>登录账号:</td>
77 <td><input type="text" name="username" id="username"></td>
78 </tr>
79 <tr>
80 <td>登录密码:</td>
81 <td><input type="password" name="password" id="password" ></td>
82 </tr>
83 <tr>
84 <td>性别:</td>
85 <td>
86 <select name="sex">
87 <option value="男">男</option>
88 <option value="女">女</option>
89 </select>
90 </td>
91 </tr>
92 <tr>
93 <td>姓名:</td>
94 <td><input type="text" name="name"></td>
95 </tr>
96 <tr>
97 <td>学号:</td>
98 <td><input type="text" name="stuname" id="stuname"></td>
99 </tr>
100 <tr>
101 <td>电子邮箱:</td>
102 <td><input type="text" name="email" id="email"></td>
103 </tr>
104 <tr>
105 <td>所在学院:</td>
106 <td><input type="text" name="xueyuan"></td>
107 </tr>
108 <tr>
109 <td>所在系:</td>
110 <td><input type="text" name="xi"></td>
111 </tr>
112 <tr>
113 <td>所在班级:</td>
114 <td><input type="text" name="banji"></td>
115 </tr>
116 <tr>
117 <td>入学年份(届):</td>
118 <td>
119 <select name="year">
120 <option value="1998">1998</option>
121 <option value="1999">1999</option>
122 <option value="2000">2000</option>
123 <option value="2001">2001</option>
124 <option value="2002">2002</option>
125 <option value="2003">2003</option>
126 <option value="2004">2004</option>
127 <option value="2005">2005</option>
128 <option value="2006">2006</option>
129 <option value="2007">2007</option>
130 <option value="2008">2008</option>
131 <option value="2009">2009</option>
132 <option value="2010">2010</option>
133 <option value="2011">2011</option>
134 <option value="2012">2012</option>
135 <option value="2013">2013</option>
136 <option value="2014">2014</option>
137 <option value="2015">2015</option>
138 <option value="2016">2016</option>
139 <option value="2017">2017</option>
140 <option value="2018">2018</option>
141 <option value="2019">2019</option>
142 </select>
143 </td>
144 </tr>
145 <tr>
146 <td>生源地:</td>
147 <td><input type="text" name="address"></td>
148 </tr>
149 <tr>
150 <td>
151 备注: 152 </td>
153 <td>
154 <input type="text" name="addtext" >
155 </td>
156 </tr>
157 <tr>
158 <th colspan="2">
159 <input type="submit" value="添加">
160 </th>
161 </tr>
162 </form>
163 </table>
164 </body>
165 </html>
四、程序测试
