初次Java web項目的建立以及與數據庫的連接

題目要求：

 

 

 

1登錄賬號：要求由6到12位字母、數字、下划線組成，只有字母可以開頭；（1分）

2登錄密碼：要求顯示“• ”或“*”表示輸入位數，密碼要求八位以上字母、數字組成。（1分）

3性別：要求用單選框或下拉框實現，選項只有“男”或“女”；（1分）

4學號：要求八位數字組成，前四位為“2018”開頭，輸入自己學號；（1分）

5姓名：輸入自己的姓名；

5電子郵箱：要求判斷正確格式[e-mail]；（1分）

6點擊“添加”按鈕，將學生個人信息存儲到數據庫中。（3分）

7可以演示連接上數據庫。（2分）

思路：

先建立一個web項目，制作網頁。然后在src目錄下建立四個包。

第一個包，bean包，包括userbean類，代碼如下，主要進行，數據的聲明，和get()、set()、有參構造方法和無參構造方法

 

package com.user.bean;

public class UserBean {
    private String id;
    private String pass;
    private String sex;
    private String name;
    private String xue;
    private String e_mail;
    private String yuan;
    private String xi;
    private String ban;
    private String nian;
    private String di;
    private String bei;

    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getPass() {
        return pass;
    }
    public void setPass(String pass) {
        this.pass = pass;
    }
    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 getXue() {
        return xue;
    }
    public void setXue(String xue) {
        this.xue = xue;
    }
    public String getE_mail() {
        return e_mail;
    }
    public void setE_mail(String e_mail) {
        this.e_mail = e_mail;
    }
    public String getYuan() {
        return yuan;
    }
    public void setYuan(String yuan) {
        this.yuan = yuan;
    }
    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 getDi() {
        return di;
    }
    public void setDi(String di) {
        this.di = di;
    }
    public String getBei() {
        return bei;
    }
    public void setBei(String bei) {
        this.bei = bei;
    }
    
    public UserBean() {}
    public UserBean(String Id,String Pass,String Sex,String Name,String Xue,String E_mail,String Yuan,String Xi,String Ban,String Nian,String Di,String Bei)
    {
        this.id=Id;
        this.pass=Pass;
        this.sex=Sex;
        this.name=Name;
        this.xue=Xue;
        this.e_mail=E_mail;
        this.yuan=Yuan;
        this.xi=Xi;
        this.ban=Ban;
        this.nian=Nian;
        this.di=Di;
        this.bei=Bei;
    }
}

 

第二個包，dao層封裝方法

package com.user.dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import com.user.bean.UserBean;
import com.util.DBUtil;

public class UserDao {
    public static void main(String[] args) {
//        List<UserBean> users=new ArrayList<UserBean>();
//        UserBean user=new UserBean();
//        user=list("1");
//        System.out.println(user.getId_zaibu());
//        checkLogin("root","root");
        
    }
    
    /**
     * 注冊
     * @param userBean
     */
    public void reg(UserBean userBean) {
        String sql = "insert into login(Id,Pass,Sex,Name,Xue,E_mail,Yuan,Xi,Ban,Nian,Di,Bei) values('"+userBean.getId()+"','"+userBean.getPass()+"','"+userBean.getSex()+"','"+userBean.getName()+"','"+userBean.getXue()+"','"+userBean.getE_mail()+"','"+userBean.getYuan()+"','"+userBean.getXi()+"','"+userBean.getBan()+"','"+userBean.getNian()+"','"+userBean.getDi()+"','"+userBean.getBei()+"')";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        try {
            state = conn.createStatement();
            state.executeUpdate(sql);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            DBUtil.close(state, conn);
        }
    }
}

第三個包，servlet層，連接頁面和數據庫；

package com.user.servlet;

import java.io.IOException;
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 javax.servlet.http.HttpSession;

import com.user.bean.UserBean;
import com.user.dao.UserDao;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
//        response.getWriter().append("Served at: ").append(request.getContextPath());
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        HttpSession session=req.getSession();
        
        String Id = req.getParameter("Id");
        String Pass = req.getParameter("Pass");
        String Name = req.getParameter("Name");
        String Sex = req.getParameter("Sex");
        String Xue = req.getParameter("Xue");
        String Di = req.getParameter("Di");
        String Yuan = req.getParameter("Yuan");
        String E_mail = req.getParameter("E_mail");
        String Xi = req.getParameter("Xi");
        String Ban = req.getParameter("Ban");
        String Nian = req.getParameter("Nian");
        String Bei = req.getParameter("Bei");

        UserDao adminDao = new UserDao();
        UserBean a=new UserBean();
        a.setId(Id);
        a.setPass(Pass);
        a.setName(Name);
        a.setXue(Xue);
        a.setSex(Sex);
        a.setDi(Di);
        a.setXi(Xi);
        a.setBan(Ban);
        a.setNian(Nian);
        a.setBei(Bei);
        a.setE_mail(E_mail);
        a.setYuan(Yuan);
        adminDao.reg(a);
        resp.sendRedirect(req.getContextPath() + "/Sussess.jsp");
    }
    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

第四個包，封裝工具層

package com.util;

public class Constants {
    public static final String SESSION_LOGIN_BEAN="loginbean";

}

package com.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 數據庫的工具類
 * @author zm
 *
 */
public class DBUtil {
    //eshop為數據庫名稱，db_user為數據庫用戶名db_password為數據庫密碼
public static String db_url ="jdbc:mysql://localhost:3306/daer?&useSSL=false&serverTimezone=UTC";
    public static String db_user = "root";
    public static String db_password = "root";
    public static Connection getConn() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(db_url, db_user, db_password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return 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();
            }
        }
    }
}

package com.util;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class StringUtil {

    /**
     * @param str
     * @return
     */
    public static int StringToInt(String str) {
        int result = 0;
        try {
            result = Integer.parseInt(str);
        } catch (NumberFormatException e) {
            result = 0;
            //e.printStackTrace();
        }
        return result;
    }
    /**
     * @param length
     * @return
     */
    public static String getRandomString(int length) { 
        String base = "abcdefghijklmnopqrstuvwxyz0123456789";   
        Random random = new Random();   
        StringBuffer sb = new StringBuffer();   
        for (int i = 0; i < length; i++) {   
            int number = random.nextInt(base.length());   
            sb.append(base.charAt(number));   
        }   
        return sb.toString();   
     }
    
    public static List<String> splitProperties (String properties){
        List<String> options = new ArrayList<String>();
        String option = null;
        String[] strings = properties.split(",");
        for (String string : strings) {
            if(!"0".equals(string)){
                option = string.charAt(3)+"";
                options.add(option);
                
            }
        }
        return options;
        
    }
    /**
     * @param str
     * @return
     */
    public static float strToFlo(String str) {
        float i = 0;
        try {
            i = Integer.parseInt(str);
        } catch (Exception e) {
        }
        return i;
    }
}

網頁界面：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>登錄</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style type="text/css">  
        .code   
        {   
            background-image:url(code.jpg);   
            font-family:Arial;   
            font-style:italic;   
            color:Red;   
            border:0;   
            padding:2px 3px;   
            letter-spacing:3px;   
            font-weight:bolder;   
        }   
        .unchanged   
        {   
            border:0;   
        }   
    </style>
    <script type="text/javascript">
    function validate()
    {
        
        var Id=document.forms["myForm"]["Id"].value;
        var reg= /^[A-Za-z0-9]{6,12}$/;
        
        if(!Id.match(reg))
            {
            alert("登陸賬號必須由六到十二英文字符或數字組成，以英文字母開頭");
            return false;
            }
        var Pass=document.forms["myForm"]["Pass"].value;
         reg= /^[A-Za-z0-9]{8,20}$/;
         if(!Pass.match(reg))
         {
         alert("密碼必須由八位以上英文字符或數字組成");
         return false;
         }
        
         var Xue=document.forms["myForm"]["Xue"].value;
         reg= /^[0-9]{8}$/;
         if(!Xue.match(reg))
         {
         alert("要求八位數字組成，前四位為“2018”開頭");
         return false;
         }
         var E_mail=document.forms["myForm"]["E_mail"].value;
         reg=/^([0-9A-Za-z\-_\.]+)@([0-9a-z]+\.[a-z]{2,3}(\.[a-z]{2})?)$/g;
             if(!E_mail.match(reg))
                 {
                 alert("郵箱請輸入正確格式");
                 return false;
                 }
    }
    
    </script>
</head>
<body >
            <form name="myForm" action="${pageContext.request.contextPath}/LoginServlet" onsubmit="return validate()" method="post" >
                    <label>登陸賬號</label>
                        <input  name="Id" type="text" value="" /><br>
                    <label >登陸密碼</label>
                        <input type="Pass" name="Pass" ><br>
                    <label >性別</label>
                    <input name="Sex" type="radio" value="女">女&nbsp;&nbsp;
                    <input name="Sex" type="radio" value="男">男<br>
                    <label >姓名</label>
                        <input  name="Name" type="text" value="" /><br>
                    <label >學號</label>
                        <input  name="Xue" type="text" value="" /><br>
                    <label >電子郵件</label>
                        <input  name="E_mail" type="text" value="" /><br>
                    <label >所在學院</label>
                        <input  name="Yuan" type="text" value="" /><br>
                    <label >所在系</label>
                        <input  name="Xi" type="text" value="" /><br>
                    <label >所在班級</label>
                        <input  name="Ban" type="text" value="" /><br>
                    <label >入學年份（屆）</label>
                        <select name="Nian">
                        <%for(int i=1998;i<2020;i++){ %>
                        <option value="<%=i%>"><%=i %></option>
                        <%} %>
                        </select><br>
                    <label >生源地</label>
                        <input  name="Di" type="textarea" value="" /><br>
                    <label >備注</label>
                        <textarea name="Bei" rows="20" cols="20"></textarea><br>
                        <button type="submit">注冊</button>
                        <button type="reset" >重置</button>
            </form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<script type="text/javascript">
alert("成功！");
</script>
</body>
</html>

sql語句：

/*
Navicat MySQL Data Transfer

Source Server         : MySQL
Source Server Version : 80015
Source Host           : localhost:3306
Source Database       : daer

Target Server Type    : MYSQL
Target Server Version : 80015
File Encoding         : 65001

Date: 2019-10-21 15:21:01
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for login
-- ----------------------------
DROP TABLE IF EXISTS `login`;
CREATE TABLE `login` (
  `Id` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `Pass` varchar(255) DEFAULT NULL,
  `Sex` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `Name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `Xue` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `E_mail` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `Yuan` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `Xi` varchar(255) DEFAULT NULL,
  `Ban` varchar(255) DEFAULT NULL,
  `Nian` varchar(255) DEFAULT NULL,
  `Di` varchar(255) DEFAULT NULL,
  `Bei` varchar(255) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of login
-- ----------------------------

 

運行結果如下：

 

 

 

 

 

 

 

 

 

 

以下分別是條件不滿足，和最后滿足添加成功以及數據庫保存的內容

 

 

 

 

 

 

 

 

 

 

 體會：以后做大項目的時候，尤其要注意分層完成，條理清晰，哪里出了問題可以去改，而且做完一個小類就要去測試，是否正確，不要等到所有內容全部完成，因為全部完成的話，代碼量很大，出問題了你也不知道如何去改，很費時間，相反，保證每個小項目都沒有錯，那么大的錯誤也不會有。初次做java web項目有些不熟悉，連數據庫也不太會，只有多多練習，別人的代碼不是你的代碼，別人告訴你的代碼，你不一定會，同樣，從網上找到的模板你不一定會，因此一定要自己寫代碼，寫明白，這樣才是自己真的會了，否則，你這次找別人要的代碼，下次也還會是，你永遠也不會進步，就像是愚公一樣，哪怕自己一次弄不明白，可以千次萬次，這樣也會進步，可就是不能去復制粘貼，別人的代碼，一知半解或者壓根都不明白，這才是最可怕的，表面上很厲害，但是真拿出來，自己又是不會，因此，要培養自己獨立動手思考還有改錯的能力