一,题目:
一、 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:;(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)
二思路
1,首先按要求编写出WEB网页。
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文件中编写对 sql 语句的拼接以及执行 sql 语句向数据库中添加东西的函数
DBUtil代码
package classtest; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /** * 数据库连接工具 * @author 李泽宇 * */ public class DBUtil { //联结字符串 //数据库名test public static String db_url = "jdbc:mysql://localhost:3306/test1?&useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC"; //数据库用户名 public static String db_user = "root"; //数据库密码名 public static String db_pass = "root"; public static Connection getConn () { //声明与数据库的连接并实例化为null Connection conn = null; try { //驱动程序名" Class.forName("com.mysql.cj.jdbc.Driver");//连接数据库 //具体地连接到数据库——联接字符串(数据库名),联接用户名,联接密码名 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(); } } } }
Grade代码
package classtest; public class Grade { private String username; private String password; private String sex; private String name; private String number; private String mail; private String xuexiao; private String xi; private String ban; public Grade(String username, String password, String sex, String name, String number, String mail, String xuexiao, String xi, String ban, String nian, String area, String base) { super(); this.username = username; this.password = password; this.sex = sex; this.name = name; this.number = number; this.mail = mail; this.xuexiao = xuexiao; this.xi = xi; this.ban = ban; this.nian = nian; this.area = area; this.base = base; } private String nian; private String area; private String base; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getNumber() { return number; } public void setNumber(String number) { this.number = number; } public String getMail() { return mail; } public void setMail(String mail) { this.mail = mail; } public String getXuexiao() { return xuexiao; } public void setXuexiao(String xuexiao) { this.xuexiao = xuexiao; } public String getXi() { return xi; } public void setXi(String xi) { this.xi = xi; } public String getBan() { return ban; } public void setBan(String ban) { this.ban = ban; } public String getNian() { return nian; } public void setNian(String nian) { this.nian = nian; } public String getArea() { return area; } public void setArea(String area) { this.area = area; } public String getBase() { return base; } public void setBase(String base) { this.base = base; } }
dao代码
package classtest; 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 classtest.Grade; import classtest.DBUtil;; public class dao { //添加 //添加入Grade表里 public boolean insert(Grade grade) { String sql="insert into test12(username,password,sex,name,number,mail,xuexiao,xi,ban,nian,area,base) values('"+grade.getUsername()+"','"+grade.getPassword()+"','"+grade.getSex()+"','"+grade.getName()+"','"+grade.getNumber()+"','"+grade.getMail()+"','"+grade.getXuexiao()+"','"+grade.getXi()+"','"+grade.getBan()+"','"+grade.getNian()+"','"+grade.getArea()+"','"+grade.getBase()+"')"; //insert语句: //insert INTO table_name (column1,column2,column3,...) VALUES (value1,value2,value3,...); //注意:insert这里 values(100,'李泽宇','"+bianliang+"'),数字可以直接上,字符串的话用 '',变量的话要用 '"++"' Connection conn=DBUtil.getConn();//数据库连接,加载驱动 Statement state=null;//数据库操作 try { state=conn.createStatement();//实例化Statement对象,方便对sql语句进行操作 state.executeUpdate(sql); //执行数据库更新操作用于执行INSERT、UPDATE或DELETE语句以及SQLDDL(数据定义语言)语句, //例如CREATETABLE和DROPTABLE,(创建表和删除表) }catch(Exception e)//当try语句中出现异常时,会执行catch中的语句 { e.printStackTrace();//捕获异常的语句 } finally //finally作为异常处理的一部分,它只能用在try/catch语句中,并且附带一个语句块,表示这段语句最终一定会被执行(不管有没有抛出异常),经常被用在需要释放资源的情况下。 { DBUtil.close(state, conn); //close释放资源 } return false; } //删除 //根据ID删除 public List<Grade> list() { String sql="select * from test12 order by uesrname ASC"; //select语句 //select * from tabel_name 这是查询所有,若要查询某一列 //select column1_name,column2_name,column3_name from table_name List<Grade>list=new ArrayList<>(); //给集合list创造(new)一个存储空间用于存放数据 Connection conn=DBUtil.getConn(); Statement state=null; ResultSet rs=null; try { state=conn.createStatement(); rs=state.executeQuery(sql); Grade grade=null; while(rs.next()) //这里表示,当rs.next()有值得时候,即收到查询结果 { String username=rs.getString("username"); //注意:这里用双引号,ID是表grade_student里的ID列 String password=rs.getString("password"); String sex=rs.getString("sex"); String name=rs.getString("name"); String number=rs.getString("number"); String mail=rs.getString("mail"); String xuexiao=rs.getString("xuexiao"); String xi=rs.getString("xi"); String ban=rs.getString("ban"); String nian=rs.getString("nian"); String area=rs.getString("area"); String base=rs.getString("base"); grade=new Grade(username,password,sex,name,number,mail,xuexiao,xi,ban,nian,area,base); list.add(grade); //表示,把bean里的数据存入到list当中 } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(state, conn); } return list; } //验证学生是否唯一 public boolean id(String username) { boolean flag = false; String sql = "select username from test12 where username = '" + username + "'"; Connection conn = DBUtil.getConn(); Statement state = null; ResultSet rs = null; try { state = conn.createStatement(); rs = state.executeQuery(sql); //要用statement类的executeQuery()方法来下达select指令以查询数据库, //executeQuery()方法会把数据库响应的查询结果存放在ResultSet类对象中供我们使用。 while (rs.next()) { flag = true; } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(rs, state, conn); } return flag; } }
service代码
package classtest; import java.util.List; import classtest.dao; import classtest.Grade; /** * CourseService * 服务层 * @author Hu * */ //service层相当于一个封装层,封装那些与业务相关的通用数据接口 public class service { dao cdao=new dao(); /** * 添加 * @param course * @return */ public boolean insert(Grade grade) { boolean f=false; if(!cdao.id(grade.getUsername())) { cdao.insert(grade); f=true; } return f; } //删除 //全部数据遍历 public List<Grade>list() { return cdao.list(); } }
servlet代码
package classtest; 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 classtest.Grade; import classtest.service; @WebServlet("/servlet") public class servlet extends HttpServlet //继承的是 HttpServlet方法,和网页交互的方法 { private static final long serialVersionUID = 1L; service service=new service(); //方法选择 protected void service(HttpServletRequest req,HttpServletResponse resp)throws ServletException, IOException { //req是Request(请求)的简写,指的是从jsp/html界面请求回数据,即 jsp/html → 底层 //resp是Response(回答)的简写,指的是发送给jsp/html的数据,,即 底层 → jsp/html req.setCharacterEncoding("utf-8");//设置从jsp或HTML中请求数据的值,也就是设置为中文,防止乱码 String method=req.getParameter("method");//getParameter()获取的是客户端设置的数据。 if ("insert".equals(method)) { insert(req, resp); } //增 else if ("list".equals(method)) { list(req, resp); } //查 } //添加 private void insert(HttpServletRequest req,HttpServletResponse resp)throws IOException, ServletException { //首先读取前端网页数据并将数据存入我创建的grade存储空间里,即 jsp/html → servlet req.setCharacterEncoding("utf-8"); //从网页获得数据 String username=req.getParameter("username"); String password=req.getParameter("password"); String sex=req.getParameter("sex"); //因为req.getParameter只能获得String类型的数据 //所以下面需要用Integer.parseInt(req.getParameter())来把String类型的数据转换成我们所需的int数据 String name=req.getParameter("name"); String number=req.getParameter("number"); String mail=req.getParameter("mail"); String xuexiao=req.getParameter("xuexiao"); String xi=req.getParameter("xi"); String ban=req.getParameter("ban"); String nian=req.getParameter("nian"); String area=req.getParameter("area"); String base=req.getParameter("base"); Grade login=new Grade(username,password,sex,name,number,mail,xuexiao,xi,ban,nian,area,base); //其次进行把grade里的数据与添加到数据库里,即 servlet → mysql数据库 //并跳转,req.getRequestDispatcher("add.jsp").forward(req, resp);这一步是跳转到前端jsp/html界面 if(service.insert(login)) //如果添加成功 { req.setAttribute("message", "添加成功"); //这里表示,在req的作用域中设置一个massage变量,变量内容是:添加成功 //然后,当跳转到它下一个界面时,这个作用域里的值可以通过Object message =request.getAttribute("message")拿出来使用 req.getRequestDispatcher("index.jsp").forward(req, resp); //处理完了,分发到下一个JSP页面或者下一个Action继续处理。 } else { req.setAttribute("message", "添加重复,请重新输入"); req.getRequestDispatcher("zhuce.jsp").forward(req, resp); } } //全部 private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); List<Grade> login_list = service.list(); req.setAttribute("login_list", login_list); req.getRequestDispatcher("list.jsp").forward(req,resp); } }
网页版zhuce界面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> </head> <body > <% Object message = request.getAttribute("message"); if(message!=null && !"".equals(message)){ %> <script type="text/javascript"> alert("<%=request.getAttribute("message")%>"); </script> <%} %> <font>当前位置:添加学生信息</font> <form action="servlet?method=insert" method="post" onsubmit="return check()"> 登录账号:<input type="text" id="username" name="username"><br /> 登录密码:<input type="password" id="password" name="password" ><br /> 性别:<input type="radio" name="sex" value="男">男 <input type="radio" name="sex" value="女">女<br /> 姓名:<input type="text" id="name" name="name"><br /> 学号:<input type="text" id="number" name="number"><br /> 电子邮件:<input type="text" id="mail" name="mail"> <br /> 所在学院<input type="text" id="xuexiao" name="xuexiao"><br /> 所在系:<input type="text" id="xi" name="xi"><br /> 所在班级:<input type="text" id="ban" name="ban"><br /> 入学年份:<select name="nian"> <option>请选择</option> <option>2017</option> <option>2018</option> <option>2019</option> </select>届<br /> 生源地:<input type="text" id="area" name="area"><br /> 备注: <textarea name="base"> </textarea><br /> <div> <button type="submit" >添 加</button> </div> </form> <script type="text/javascript"> function check() { var username = document.getElementById("username"); var password = document.getElementById("password"); var mail= document.getElementById("mail"); var number=document.getElementById("number"); //判断是否空 var res=/^[0-9a-zA-Z]*$/g; //必须是数字和英文组合 var length1=username.length; var myPattern = new RegExp("^[a-zA-Z]");//以英文字母开头 var usernamelength=document.getElementById("username").value.length; if(!((res.test(username.value))&&(myPattern.test(username.value))&&usernamelength>5&&usernamelength<=13)) { alert('用户名必须为字母数字为组成首字母大写'); username.focus(); return false; } var length=document.getElementById("password").value.length; if((res.test(password.value)&&length>=8)) { alert('由八位以上英文和数字组成'); password.focus(); return false; } if((number.value[0]!=2||number.value[1]!=0||number.value[2]!=1||number.value[3]!=8)||number.value.length!=8){ alert("学号格式不正确"); number.focus(); return false; } var kao=/^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+/; if(!(kao.test(mail.value))) {alert("邮箱格式不正确"); mail.focus(); return false;} } </script> </body> </html>