java web第一次课堂测试1
---恢复内容开始---
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：
package database;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DB {public static String db_url = "jdbc:mysql://localhost:3306/student?useSSL=false&serverTimezone=UTC&characterEncoding=UTF-8";
public static String db_user = "root";
public static String db_pass = "abc456";
public static Connection getConn () {
Connection conn = null;
try {
Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动
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();
}
}
}
public static void main(String[] args) throws SQLException {
Connection conn = getConn();
PreparedStatement pstmt = null;
ResultSet rs = null;
String sql ="select * from USER";
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
if(rs.next()){
System.out.println("空");
}else{
System.out.println("不空");
}
}
}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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