java web第一次课堂测试1
Posted 武神酱丶
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要求如图:
本程序包括四个文件,一个显示界面的jsp文件,一个dao层文件,一个servlet层文件 一个连接数据库的文件
下面依次附上代码:
前端界面:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>注册界面</title> <script type="text/javascript"> /*表单校验*/ function check() { f=0; var re = /^[\\w\\u4e00-\\u9fa5]{6,8}$/; //判断字符串是否为数字和字母组合 var myPattern = new RegExp("^[a-zA-Z]"); // 以英文字母开头 var username = document.getElementById("username").value; //alert(username.length); if(!(username.length>5&&username.length<13)){ alert("用户名长度错误!");return false; } else if(!(re.test(username))){ alert("用户名组成内容错误!");return false; }else if(!(myPattern.exec(username))){ alert("用户名开头必须是字母!");return false; } var password = document.getElementById("password").value; var pas= /\\w/; if(password.length<8){f++;alert("密码长度必须大于8位!");return false;} if(!(pas.test(password))){ alert("密码应由数字和字母组成!");return false; } var xuehao = document.getElementById("xuehao").value; if(xuehao.length!=8){ alert("学号必须为8位!");return false; } if(xuehao[0]==\'2\'&&xuehao[1]==\'0\'&&xuehao[2]==\'1\'&&xuehao[3]==\'8\'){f++;} else{ alert("学号必须以2018开头!");return false; } var mail = document.getElementById("mail").value; if(/^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+/.test(mail)){f++;} else{ alert("邮箱格式错误!");return false; } if(f>1){ alert("恭喜您已入住铁大软工大家(da)庭(keng)!"); return true; } else{ return false; } } </script> </head> <STYLE TYPE="text/css"> <!-- BODY {background-image:URL(1.png); background-position:center; background-repeat:no-repeat; background-atachment:fixed; } table{margin:auto} --> </STYLE> <body > <form action="UserServlet?method=add" method="post" onsubmit="return check()"><br/><br/><br/><br/><br/><br/><br/> <table frame= "box"> <tr> <td>登入账号:</td> <td><input type="text" id="username" name="username" value="" ></td> <td>账号应为6到12位的英文或数字,下划线组成,且由英文开头.<td> </tr> <tr> <td>登入密码:</td> <td> <input type="password" id="password" name="password" value="" ></td> <td>密码应由大于8位的数字和英文组成.<td> </tr> <tr> <td>性 别:</td> <td> <select id="sex" name="sex" > <option>--请选择--</option> <option value="男">男</option> <option value="女">女</option> </select> </td> </tr> <tr> <td>姓 名:</td> <td> <input type="text" name="name" value="" ></td> </tr> <tr> <td>学 号:</td> <td> <input type="text" name="xuehao" id="xuehao" value="" ></td> <td>学号应为2018开头的八位数字.<td> <tr> <td>电子邮件:</td> <td> <input type="text" id="mail" name="mail" value="" ></td> <td>电子邮件应符合其格式.<td> </tr> <tr> <td>所在学院:</td> <td> <input type="text" id="xueyuan" name="xueyuan" value="" ></td> </tr> <tr> <td>所在系:</td> <td> <input type="text" id="xi" name="xi" value="" ></td> </tr> <tr> <td>所在班级:</td> <td> <input type="text" id="ban" name="ban" value="" ></td> </tr> <tr> <td>入学年份(届):</td> <td> <select id="year" name="year"> <option>--请选择--</option> <option value="2018">2018</option> <option value="2017">2019</option> <option value="2016">2018</option> <option value="2015">2019</option> <option value="2014">2018</option> </select> </td> </tr> <tr> <td>生源地:</td> <td> <select name="address"> <option value ="河北省">河北省</option> <option value ="北京市">北京市</option> <option value ="天津市">天津市</option> <option value ="武安市">武安市</option> </select> </td> </tr> <tr> <td>备注:</td> <td> <input type="text" id="beizhu" name="beizhu" value="" ></td> </tr> <tr> <td><td> <td> <button type="submit" >添 加</button></td> </tr> </table> </form> </body> </html>
servlet层文件:
package Servlet; import java.io.IOException; import java.io.IOException; import java.sql.Connection; import java.sql.PreparedStatement; import dao.Dao; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class UserServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public UserServlet() { super(); // TODO Auto-generated constructor stub } Dao dao = new Dao(); protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("utf-8"); String method = req.getParameter("method"); System.out.println(method); if ("add".equals(method)) { System.out.println("ok"); String user = req.getParameter("username"); String password = req.getParameter("password"); String sex = req.getParameter("sex"); String name = req.getParameter("name"); String xuehao = req.getParameter("xuehao"); String mail = req.getParameter("mail"); String school = req.getParameter("xueyuan"); String xi = req.getParameter("xi"); String banji = req.getParameter("ban"); String nianfen = req.getParameter("year"); String place = req.getParameter("address"); String beizhu = req.getParameter("beizhu"); boolean pd=Dao.add(user, password, sex, name, xuehao, mail, school, xi, banji, nianfen, place, beizhu); if(pd) { req.setAttribute("message", "注册成功"); req.getRequestDispatcher("register.jsp").forward(req,resp); }else { req.setAttribute("message", "注册失败,请重新注册"); req.getRequestDispatcher("register.jsp").forward(req,resp); } } } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.getWriter().append("Served at: ").append(request.getContextPath()); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } }
dao层文件:
package dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import database.DB; public class Dao { public static boolean add(String username,String password,String sex,String name,String xuehao,String mail,String school,String xi,String banji,String nianfen,String place,String beizhu) { Connection conn = null; PreparedStatement pstmt = null; boolean pd = false; System.out.println("add run!"); try { //获取连接 conn = DB.getConn(); //编写语句 String sql = "insert into student values(?,?,?,?,?,?,?,?,?,?,?,?)"; //预编译 pstmt = conn.prepareStatement(sql); //设置数据 pstmt.setString(1, username); pstmt.setString(2, password); pstmt.setString(3, sex); pstmt.setString(4, name); pstmt.setString(5, xuehao); pstmt.setString(6, mail); pstmt.setString(7, school); pstmt.setString(8, xi); pstmt.setString(9, banji); pstmt.setString(10, nianfen); pstmt.setString(11, place); pstmt.setString(12, beizhu); //执行 int res = pstmt.executeUpdate(); //判断 if(res>0) { pd=true; }else { pd=false; } } catch (Exception e) { e.printStackTrace(); }finally { DB.close(pstmt,conn); } return pd; } }
连接数据库的文件:
1 package database; 2 import java.sql.Connection; 3 import java.sql.DriverManager; 4 import java.sql.PreparedStatement; 5 import java.sql.ResultSet; 6 import java.sql.SQLException; 7 import java.sql.Statement; 8 9 public class DB {public static String db_url = "jdbc:mysql://localhost:3306/student?useSSL=false&serverTimezone=UTC&characterEncoding=UTF-8"; 10 11 public static String db_user = "root"; 12 public static String db_pass = "abc456"; 13 14 public static Connection getConn () { 15 Connection conn = null; 16 17 try { 18 Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动 19 conn = DriverManager.getConnection(db_url, db_user, db_pass); 20 } catch (Exception e) { 21 e.printStackTrace(); 22 } 23 24 return conn; 25 } 26 27 /** 28 * 关闭连接 29 * @param state 30 * @param conn 31 */ 32 public static void close (Statement state, Connection conn) { 33 if (state != null) { 34 try { 35 state.close(); 36 } catch (SQLException e) { 37 e.printStackTrace(); 38 } 39 } 40 41 if (conn != null) { 42 try { 43 conn.close(); 44 } catch (SQLException e) { 45 e.printStackTrace(); 46 } 47 } 48 } 49 50 public static void close (ResultSet rs, Statement state, Connection conn) { 51 if (rs != null) { 52 try { 53 rs.close(); 54 } catch (SQLException e) { 55 e.printStackTrace(); 56 } 57 } 58 59 if (state != null) { 60 try { 61 state.close(); 62 } catch (SQLException e) { 63 e.printStackTrace(); 64 } 65 } 66 67 if (conn != null) { 68 try { 69 conn.close(); 70 } catch (SQLException e) { 71 e.printStackTrace(); 72 } 73 } 74 } 75 76 public static void main(String[] args) throws SQLException { 77 Connection conn = getConn(); 78 PreparedStatement pstmt = null; 79 ResultSet rs = null; 80 String sql ="select * from USER"; 81 pstmt = conn.prepareStatement(sql); 82 rs = pstmt.executeQuery(); 83 if(rs.next()){ 84 System.out.println("空"); 85 }else{ 86 System.out.println("不空"); 87 } 88 } 89 90 91 }
运行结果截图:
点击添加按钮后数据库数据界面:
由此可见,运行已成功
设计思路:
1.设计前端界面,并用jsp文件书写判别语句。用表格存储数据。
2.将表格存储的数据发送到servlet层,
3.servlet层发送到dao层进行数据库添加。
4.dao层调用DB层进行数据库连接。
遇到的问题:
在编写这个程序时,遇到了极其多的问题
最先出现的问题是,在进行创建web项目的时候,忘记了某个选项,导致少了web.xml文件,使得servlet层无法找到。
在进行查阅资料后,重新配置了servlet,但在添加后却没有发现jar包文件。在百度后发现需要把jar包放到tomcat下的lib文件夹才能调用。
解决了这个问题后,发现又提示数据库的编码方式不对,原来是没有设置好数据库的编码方式为UTF-8,在重新设置后,终于可用了。
通过这次过程,我意识到一些事情:
首先,就是在做东西前一定要理清思路,这次的问题就在于我做东西虎头虎脑的,没有理清在编写软件中的流程和细节问题。
再其次,就是对一些细小的事情并没有在意,导致最后发生很大的错误。
总的来说,这次学到了html中表格的写法,jsp的判断方法,数据库的连接方法。
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