JAVA web中的一些代码应用_web中的代码-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_45378285/article/details/106750283

分开jsp页面

在html中不能写jsp的代码
${pageContext.resquest.ContextPath}相当于/chatper06
jsp的动作元素
jsp:forward</jsp:forward>

写一个index.jsp,跳到首页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>$Title$</title>
</head>
<body>
<jsp:forward page="client/index.jsp"></jsp:forward>
</body>
</html>

foot.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<div id="divfoot">
	<table width="100%" border="0" cellspacing="0">
		<tr>
			<td rowspan="2" style="width: 10%"><img
				src="${pageContext.request.contextPath}/client/images/logo.png"
				width="195" height="50" style="margin-left: 175px" />
			</td>
			<td style="padding-top: 5px; padding-left: 50px"><a href="#">
					<font color="#747556"><b>CONTACT US</b> </font> </a>
			</td>
		</tr>
		<tr>
			<td style="padding-left: 50px"><font color="#CCCCCC"> <b>COPYRIGHT
						2015 &copy; BookStore All Rights RESERVED.</b> </font>
			</td>
		</tr>
	</table>
</div>

head.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<div id="divhead">
	<table cellspacing="0" class="headtable">
		<tr>
			<td>
				<a href="index.jsp">
					<img src="${pageContext.request.contextPath}/client/images/logo.png" width="200" height="60" border="0" /> 
				</a>
			</td>
			<td style="text-align:right">
				<img src="${pageContext.request.contextPath}/client/images/cart.gif" width="26" height="23" style="margin-bottom:-4px" />&nbsp;<a href="#">购物车</a> 
				| <a href="#">帮助中心</a> 
				| <a href="#">我的帐户</a>
				| <a href="${pageContext.request.contextPath}/client/register.jsp">新用户注册</a>							
			 
			</td>		
		</tr>
	</table>
</div>

index.jsp

<%@ 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>首页</title>
<link rel="stylesheet" href="${pageContext.request.contextPath}/client/css/main.css" type="text/css" />
<!-- 导入首页轮播图css和js脚本 -->
<link type="text/css" href="${pageContext.request.contextPath}/client/css/autoplay.css" rel="stylesheet" />
<script type="text/javascript" src="${pageContext.request.contextPath}/client/js/autoplay.js"></script>
</head>
<body class="main">
<!-- 1.网上书城顶部 start -->
	  <%@include file="head.jsp"%>
<!-- 网上书城顶部  end -->

<!-- 2.网上书城菜单列表  start -->
	<%@include file="menu_search.jsp" %>
<!-- 网上书城菜单列表  end -->

<!-- 3.网上书城首页轮播图  start -->
	<div id="box_autoplay">
    	<div class="list">
        	<ul>
            	<li><img src="${pageContext.request.contextPath}/client/ad/index_ad1.jpg" width="900" height="335" /></li>
            	<li><img src="${pageContext.request.contextPath}/client/ad/index_ad2.jpg" width="900" height="335" /></li>
            	<li><img src="${pageContext.request.contextPath}/client/ad/index_ad3.jpg" width="900" height="335" /></li>
            	<li><img src="${pageContext.request.contextPath}/client/ad/index_ad4.jpg" width="900" height="335" /></li>
            	<li><img src="${pageContext.request.contextPath}/client/ad/index_ad5.jpg" width="900" height="335" /></li>
        	</ul>
    	</div>
	</div>
<!-- 网上书城首页轮播图  end -->
<!-- 4.公告板和本周热卖  start -->
    <div id="divcontent">
		<table width="900px" border="0" cellspacing="0">
			<tr>
				<td width="497">
				
					<img src="${pageContext.request.contextPath}/client/images/billboard.gif" width="497" height="38" />
					<table cellspacing="0" class="ctl">
						<tr>
							<td width="485" height="29">
				                            尊敬的网上书城用户， 　　<br>
							　　为了让大家有更好的购物体验，3月25日起，当日达业务关小黑屋回炉升级！<br>具体开放时间请留意公告，感谢大家的支持与理解，祝大家购物愉快！<br>
							        3月23日<br>
							        传智播客 网上书城系统管理部<br>
							</td>
						</tr>
					</table>
				</td>
				<td style="padding:5px 15px 10px 40px">
					<table width="100%" border="0" cellspacing="0">
						<tr>
							<td>
								<img src="${pageContext.request.contextPath}/client/images/hottitle.gif" width="126" height="29" />
							</td>
						</tr>
					</table>
					<table width="100%" border="0" cellspacing="0">
						<tr>						
				             <td style="width:80; text-align:center">
								<a href="#">
								<img src="${pageContext.request.contextPath}/client/bookcover/105.jpg" width="102" height="130" border="0" />
								</a>
								<br /> 							
							</td>		
							<td style="width:80; text-align:center">
								<a href="#">
								<img src="${pageContext.request.contextPath}/client/bookcover/106.jpg" width="102" height="130" border="0" />
								</a>
								<br /> 							
							</td>			
						</tr>
					</table>
				</td>
			</tr>
		</table>
	</div>
<!-- 公告板和本周热卖  end -->		
<!--5. 网上书城底部 start -->
      <%@ include file="foot.jsp" %>
<!-- 网上书城底部  end -->
</body>
</html>

menu_search.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<div id="divmenu">
		<a href="#">文学</a> 
		<a href="#">生活</a> 
		<a href="#">计算机</a> 
		<a href="#">外语</a> 
		<a href="#">经管</a>
		<a href="#">励志</a> 
		<a href="#">社科</a> 
		<a href="#">学术</a> 
		<a href="#">少儿</a>
		<a href="#">艺术</a> 
		<a href="#">原版</a> 
		<a href="#">科技</a> 
		<a href="#">考试</a> 
		<a href="#">生活百科</a> 
		<a href="#" style="color:#FFFF00">全部商品目录</a>		
</div>
<div id="divsearch">
<form action="#" id="searchform">
	<table width="100%" border="0" cellspacing="0">
		<tr>
			<td style="text-align:right; padding-right:220px">
				Search 
				<input type="text" name="textfield" class="inputtable" id="textfield" value="请输入书名"
				onmouseover="this.focus();"
				onclick="my_click(this, 'textfield');"
				onBlur="my_blur(this, 'textfield');"/> 
				<a href="#">
					<img src="${pageContext.request.contextPath}/client/images/serchbutton.gif" border="0" style="margin-bottom:-4px" onclick="search()"/> 
				</a>
			</td>
		</tr>
	</table>
</form>
</div>

<%@ 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>用户注册</title>
<link rel="stylesheet" href="${pageContext.request.contextPath}/client/css/main.css" type="text/css" />
<script type="text/javascript" src="${pageContext.request.contextPath}/client/js/form.js"></script>
</head>
<body class="main">
<!-- 1.网上书城顶部 start -->
       <%@include file="head.jsp"%>
<!-- 网上书城顶部  end -->
<!--2. 网上书城菜单列表  start -->
       <%@include file="menu_search.jsp" %>
<!-- 网上书城菜单列表  end -->
<!-- 3.网上书城用户注册  start -->
	<div id="divcontent" align="center">
		<form action="${pageContext.request.contextPath}/client/registersuccess.jsp" method="post" onsubmit="return checkForm();">
			<table width="850px" border="0" cellspacing="0">
				<tr>
					<td style="padding: 30px"><h1>新会员注册</h1>
						<table width="70%" border="0" cellspacing="2" class="upline">
							<tr>
								<td style="text-align: right; width: 20%">会员邮箱：</td>
								<td style="width: 40%">
								<input type="text" class="textinput"  id="email" name="email" onkeyup="checkEmail();"/>
								</td>
								<td colspan="2"><span id="emailMsg"></span><font color="#999999">请输入有效的邮箱地址</font></td>
							</tr>
							<tr>
								<td style="text-align: right">会员名：</td>
								<td><input type="text" class="textinput"  id="username" name="username" onkeyup="checkUsername();"/>
								</td>
								<td colspan="2"><span id="usernameMsg"></span><font color="#999999">字母数字下划线1到10位, 不能是数字开头</font></td>
							</tr>
							<tr>
								<td style="text-align: right">密码：</td>
								<td><input type="password" class="textinput"  id="password" name="password" onkeyup="checkPassword();"/></td>
								<td><span id="passwordMsg"></span><font color="#999999">密码请设置6-16位字符</font></td>
							</tr>
							<tr>
								<td style="text-align: right">重复密码：</td>
								<td>
								<input type="password" class="textinput"  id="repassword" name="repassword" onkeyup="checkConfirm();"/>
								</td>
								<td><span id="confirmMsg"></span>&nbsp;</td>
							</tr>
							<tr>
								<td style="text-align: right">性别：</td>
								<td colspan="2">&nbsp;&nbsp;
                                <input type="radio" name="gender" value="男" checked="checked" /> 男
									&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
									<input type="radio" name="gender" value="女" /> 女
								</td>
								<td>&nbsp;</td>
							</tr>
							<tr>
								<td style="text-align: right">联系电话：</td>
								<td colspan="2">
								<input type="text" class="textinput"
									style="width: 350px" name="telephone" />
								</td>
								<td>&nbsp;</td>
							</tr>
							<tr>
								<td style="text-align: right">个人介绍：</td>
								<td colspan="2">
								<textarea class="textarea" name="introduce"></textarea>
								</td>
								<td>&nbsp;</td>
							</tr>
						</table>

						<table width="70%" border="0" cellspacing="0">
							<tr>
								<td style="padding-top: 20px; text-align: center">
									<input type="image" src="images/signup.gif" name="submit" border="0"/>
								</td>
							</tr>
						</table>
					</td>
				</tr>
			</table>
		</form>
	</div>
    <!-- 网上书城用户注册  end -->
<!--4. 网上书城下方显示 start -->
     <%@ include file="foot.jsp" %>
<!-- 网上书城下方显示 start -->
</body>
</html>

registersuccess.jsp

<%@ 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>success page</title>
</head>
<body>
<center>
	<font color="green" size="7">注册成功</font>
	</center>
</body>
</html>

使用Filter的简单自动登录

因为Cookie可以实现用户的自动登录功能
使用到的文件：index.jsp；login.jsp；AutoLoginFilter: LoginServlet;LogoutServlet.配置文件web.xml
index.jsp;User

index.jsp


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
  <head>
    <title>显示用户登录信息</title>
  </head>
  <body>
  <br/>
  <center>
    <h3>欢迎光临</h3>
  </center>
  <br/>
  <br/>
  <c:choose>
    <c:when test="${sessionScope.user.null}">
      <a href="${pageContext.request.contextPath}/login.jsp">用户登录</a>
    </c:when>
    <c:otherwise>
      欢迎您：${sessionScope.user.username}!
      <a href="${pageContext.request.contextPath}/LogoutServlet">注销</a>
    </c:otherwise>
  </c:choose>
  </body>
</html>

login.jsp


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <meta charset="UTF-8">
    <title>登录</title>
    <center><h3>用户登录</h3></center>
</head>
<body>
<form action="${pageContext.request.contextPath}/LoginServlet" method="post">
    <table border="1" width="600px" cellpadding="0" cellspacing="0" align="center">
        <tr>
            <td height="30" align="center">用户名：</td>
            <td>&nbsp;&nbsp; <input type="text" name="username">${errerMsg}</td>
        </tr>
        <tr>
            <td height="30" align="center">密   &nbsp;码:</td>
            <td>&nbsp;&nbsp;
                <input type="password" name="password"></td>
        </tr>
        <tr>
            <td height="35" align="center">自动登录时间</td>
            <td>
                <input type="radio" name="autologin" value="${60*60*24*31}">一个月
                <input type="radio" name="autologin" value="${60*60*24*31*3}">三个月
                <input type="radio" name="autologin" value="${60*60*24*31*6}">六个月
                <input type="radio" name="autologin" value="${60*60*24*31*12}">一年
            </td>
        </tr>
        <tr>
            <td height="30" colspan="2" align="center">
                <input type="submit" value="登录"/>
                &nbsp;&nbsp;&nbsp;
                <input type="reset" value="重置">
            </td>
        </tr>
    </table>
</form>
</body>
</html>

AutoLoginFilter

package com.yue.chapter08.Servlet;

import com.yue.chapter08.pojo.User;

import javax.servlet.*;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

public class AutoLoginFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //获得一个名为autologin的cookie
        HttpServletRequest req = (HttpServletRequest) servletRequest;
        Cookie[] cookies = req.getCookies();
        String autologin = null;
        for(int i= 0 ;cookies != null && i < cookies.length; i++){
            if("autologin".equals(cookies[i].getName())){
                //找到指定的cookie
                autologin = cookies[i].getValue();
                break;
            }
        }
        if(autologin != null){
            //做自动登录
            String[] split = autologin.split("-");
            String username = split[0];
            String password = split[1];
            //检查用户名和密码
            if("itcast".equals(username) && "123456".equals(password)){
                //登录成功，将用户状态user对象装入seesion域中
                User user = new User();
                user.setPassword(password);
                user.setUsername(username);
                req.getSession().setAttribute("user",user);
            }
        }
        filterChain.doFilter(req,servletResponse);

    }

    @Override
    public void destroy() {

    }
}

loginServlet

package com.yue.chapter08.Servlet;

import com.yue.chapter08.pojo.User;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获得用户名和密码
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //检查用户名和密码
        if("itcast".equals(username)&&"123456".equals(password)){
            //登录状态
            //将用户状态user对象加入Session域中
            User user = new User();
            user.setUsername(username);
            user.setPassword(password);
            req.getSession().setAttribute("user",user);
            //发送自动登录的cookie
            String autologin = req.getParameter("autologin");
            if(autologin != null){
                //注意cookie中的密码要加密
                Cookie autologin1 = new Cookie("autologin", username + "_" + password);
                autologin1.setMaxAge(Integer.parseInt(autologin));
                autologin1.setPath(req.getAuthType());
                resp.addCookie(autologin1);
            }
            resp.sendRedirect(req.getContextPath()+"/index.jsp");
        }else {
            req.setAttribute("errerMsg","用户名或密码错误");
            RequestDispatcher requestDispatcher = req.getRequestDispatcher("login.jsp");
            requestDispatcher.forward(req,resp);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

LogoutServlet

package com.yue.chapter08.Servlet;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class LogoutServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //用户注销
        req.getSession().removeAttribute("user");
        //从客户端删除自动登录的cookie
        //重新设置一个cookie去覆盖它
        Cookie autologin = new Cookie("autologin", "");
        autologin.setMaxAge(0);
        autologin.setPath(req.getContextPath());
        resp.addCookie(autologin);
        resp.sendRedirect(req.getContextPath()+ "/index.jsp");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

User

package com.yue.chapter08.pojo;

public class User {
    private String username;
    private String password;

    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;
    }


}

web.xml

 <filter>
        <filter-name>AutoLoginFilter</filter-name>
        <filter-class>com.yue.chapter08.Servlet.AutoLoginFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>AutoLoginFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <servlet>
        <servlet-name>LoginServlet</servlet-name>
        <servlet-class>com.yue.chapter08.Servlet.LoginServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LoginServlet</servlet-name>
        <url-pattern>/LoginServlet</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>LogoutServlet</servlet-name>
        <servlet-class>com.yue.chapter08.Servlet.LogoutServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LogoutServlet</servlet-name>
        <url-pattern>/LogoutServlet</url-pattern>
    </servlet-mapping>

使用Filter实现统一全站编码

根据请求的方式不同，对请求进行不同的中文乱码的方式不同，post的请求消息参数在消息体中，只需req.setCharacterEncoding("Utf-8);而对于get方法的请求：它的参数在url地址的后面，所以以采用不同的方式，

String v = req.getParmater(“username”);
使用String的构造方式进行处理中文乱码 new String(v.getBytes(“iso-8859-1”),“utf-8”);
这样就可以解决中文乱码问题
但是参数过多的话，就会导致麻烦，所以使用装配这设计模式，进行增强getParameter（）方法的方式

form.jsp

<%--
  Created by IntelliJ IDEA.
  User: 岳振彪
  Date: 2020/6/15
  Time: 21:55
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
   <center>
       <h3>用户登录</h3>
   </center>
</head>
<body style="text-align: center">
    <a href="<%=request.getContextPath()%>/CharacterServlet?username=晨晨&password=123">超链接</a>
    <form action="<%=request.getContextPath()%>/CharacterServelt" method="post">
        <table border="1" width="600px" cellpadding="0" cellspacing="0" align="center">
            <tr>
                <td height="30" align="center">用户名：</td>
                <td>&nbsp;&nbsp; <input type="text" name="username">${errerMsg}</td>
            </tr>
            <tr>
                <td height="30" align="center">密   &nbsp;码:</td>
                <td>&nbsp;&nbsp;
                    <input type="password" name="password"></td>
            </tr>
            <tr>
                <td height="30" colspan="2" align="center">
                    <input type="submit" value="登录"/>
                    &nbsp;&nbsp;&nbsp;
                    <input type="reset" value="重置">
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

CharacterFilter

package com.yue.chapter08.character;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CharacterFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse resp = (HttpServletResponse) servletResponse;
        resp.setContentType("text/html;utf-8");
        //拦截所有的请求，解决全站的中文乱码问题
        //指定request和response的编码
        String method = req.getMethod();
        if(method.equalsIgnoreCase("post")){
            req.setCharacterEncoding("utf-8");
        }
        //对request进行包装
        CharacterRequest characterRequest = new CharacterRequest(req);
        filterChain.doFilter(characterRequest,resp);

    }

    @Override
    public void destroy() {
    }

}

CharacterRequest

package com.yue.chapter08.character;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.UnsupportedEncodingException;

/*
* 继承默认包装类HttpServletRequestWrapper
* */
public class CharacterRequest extends HttpServletRequestWrapper {
    private HttpServletRequest req;
    public CharacterRequest(HttpServletRequest request) {
        super(request);
        this.req = request;
    }
    //子类继承父类，复写一些方法

    @Override
    public String getParameter(String name) {
        //调用被包装对象的getParameter(),获得请求参数
        String parameter = req.getParameter(name);
        if(parameter == null){
            return null;
        }
        //判断请求方式
        String method = req.getMethod();
        if(method.equalsIgnoreCase("get")){
            try {
                parameter = new String(parameter.getBytes("iso-8859-1"),"utf-8");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
        }
        //解决乱码后返回结果
        return parameter;
    }
}

CharacterServlet

package com.yue.chapter08.character;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CharacterServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println(req.getParameter("username"));
        System.out.println(req.getParameter("password"));
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doPost(req, resp);
    }
}

web.xml

<servlet>
        <servlet-name>CharacterServlet</servlet-name>
        <servlet-class>com.yue.chapter08.character.CharacterServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>CharacterServlet</servlet-name>
        <url-pattern>/CharacterServlet</url-pattern>
    </servlet-mapping>
    <filter>
        <filter-name>CharacterFilter</filter-name>
        <filter-class>com.yue.chapter08.character.CharacterFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CharacterFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

使用JDBC完成数据的增删改查

过程
写一个包装类Users
写一个工具类JdbcUtils,简约代码
UserDao类，对数据进行增删改查

Users

package com.yue.chapter09;

import java.util.Date;

public class Users {
    private int id;
    private String name;
    private String password;
    private Date birthday;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
}

JdbcUtils

package com.yue.chapter09;

import java.sql.*;

public class JdbcUtils {
    public static Connection getCon() throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost:3306/yun6";
        String user ="root";
        String password = "root";
        Connection conn = DriverManager.getConnection(url, user, password);
        return conn;
    }
    public static void release(ResultSet rs, Statement st,Connection conn) {
        if(rs != null){
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            rs = null;
        }
        if(st != null){
            try {
                st.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            st = null;
        }
        if(conn != null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            conn = null;
        }
    }
}

UserDao

package com.yue.chapter09;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;

public class UsersDao {
    public boolean inset(Users user){
        Connection coon = null;
        Statement st = null;
        try{
            //建立连接
             coon = JdbcUtils.getCon();
            //获得Statement对象
             st = coon.createStatement();
            //因为birthday在user中是urti,在数据库中是sql，进行转换
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
            String format = simpleDateFormat.format(user.getBirthday());
            //另一种
//            Date birthday = user.getBirthday();
//            String format1 = String.format("%tF", birthday);
            //因为使用的是statement对象，没有占位符，所以要使用拼接的方式，
            String sql = "insert into users(id,name,password,birthday)" +
                    "values("+ user.getId()+ ",'"+ user.getName() +"','"+ user.getPassword() +"','"+ format +"')";
            int i = st.executeUpdate(sql);
            if(i > 0){
                return true;
            }
            return false;
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            JdbcUtils.release(null,st,coon);
        }
        return false;
    }
    //查询所有的对象
    public ArrayList<Users> findAll(){
        Connection coon = null;
        Statement st = null;
        ResultSet rs = null;
        ArrayList<Users> users = new ArrayList<>();
        try {
            //奖励连接
           coon = JdbcUtils.getCon();
            //获取Statement
            st = coon.createStatement();
            //sql语句
            String sql = "select * from users";
            //查询，获取到结果集
            rs = st.executeQuery(sql);
            //对结果集的处理
            while (rs.next()){
                Users users1 = new Users();
                users1.setId(rs.getInt("id"));
                users1.setName(rs.getString("name"));
                users1.setPassword(rs.getString("password"));
                users1.setBirthday(rs.getDate("birthday"));
                users.add(users1);
            }
            return users;
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            JdbcUtils.release(rs,st,coon);
        }
        return null;
    }
    public Users findById(int id){
        Connection coon = null;
        PreparedStatement st = null;
        ResultSet rs = null;

        try {
            //奖励连接
            coon = JdbcUtils.getCon();
            //sql语句
            String sql = "select * from users where id=?";
            //获取Statement
          st = coon.prepareStatement(sql);
            //执行sql，为id赋值
            st.setInt(1,id);
            //查询，获取到结果集
            rs = st.executeQuery();
            //对结果集的处理
            if (rs.next()){
                Users users1 = new Users();
                users1.setId(rs.getInt("id"));
                users1.setName(rs.getString("name"));
                users1.setPassword(rs.getString("password"));
                users1.setBirthday(rs.getDate("birthday"));
                return users1;
            }

        }catch (Exception e){
            e.printStackTrace();
        }finally {
            JdbcUtils.release(rs,st,coon);
        }
        return null;
    }
    public boolean update(Users users){
        Connection coon = null;
        PreparedStatement st = null;
        try{
            //建立连接
            coon = JdbcUtils.getCon();
            //sql语句
            String sql = "update users set name =?,password=? where id=?";
            //获得Statement对象
            st = coon.prepareStatement(sql);
            //执行sql,为它赋值
            st.setString(1,users.getName());
            st.setString(2,users.getPassword());
            st.setInt(3,users.getId());
            int i = st.executeUpdate();
            if(i > 0){
                return true;
            }
            return false;
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            JdbcUtils.release(null,st,coon);
        }
        return false;
    }
    public boolean delete(int id){
        Connection coon = null;
        PreparedStatement st = null;
        try{
            //建立连接
            coon = JdbcUtils.getCon();
            //sql语句
            String sql = "delete  from users where id =?";
            //获得Statement对象
            st = coon.prepareStatement(sql);
            //执行sql,为它赋值

            st.setInt(1,id);
            int i = st.executeUpdate();
            if(i > 0){
                return true;
            }
            return false;
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            JdbcUtils.release(null,st,coon);
        }
        return false;
    }
}

测试

public class delete {
    public static void main(String[] args) {
        UsersDao usersDao = new UsersDao();
        boolean delete = usersDao.delete(2);
        System.out.println(delete);
    }
}
public class findId {
    public static void main(String[] args) {
        UsersDao usersDao = new UsersDao();
        Users byId = usersDao.findById(2);
        System.out.println(byId.getName());
    }
}
public class Insert {
    public static void main(String[] args) {
        //向用户中插入数据
        Users users = new Users();
        UsersDao usersDao = new UsersDao();
        users.setId(2);
        users.setName("ab");
        users.setPassword("456");
        users.setBirthday(new Date());
        boolean inset = usersDao.inset(users);
        System.out.println(inset);
    }
}
public class queryAll {
    public static void main(String[] args) {
        UsersDao usersDao = new UsersDao();
        ArrayList<Users> all = usersDao.findAll();
       for(int i= 0;i<all.size();i++){
           System.out.println(all.get(i).getName());
       }
    }
}
public class update {
    public static void main(String[] args) {
        UsersDao usersDao = new UsersDao();
        Users users = new Users();
        users.setId(1);
        users.setName("ee");
        users.setPassword("55");
        usersDao.update(users);
    }
}

使用DBUtils实现crud

步骤
在数据库中创建user表，用User类封装数据
创建一个工具类：C3p0Utils
创建一个dao类，DBUTilsDao
创建测试类：测试Dao的增删改查方法
QuerryRunner 类的使用方法
第一种
QueryRunner runner = new QueryRunner();
runner.query(connection,sql,处理器对象，params)
第二种
QueryRunner runner = new QueryRunner(dataSource对象);
runner.query(sql,处理器对象，params)
总结：
执行insert into,update,delete ,都使用update方法，返回int
执行select查询，调用query方法，放回List,Object,Map等对象。

C3p0Utils

package com.yue.chapter10;

import com.mchange.v2.c3p0.ComboPooledDataSource;

import javax.sql.DataSource;

public class C3p0Utils {
    public static DataSource ds = null;
    static {
        ds = new ComboPooledDataSource("itcast");
    }
    public static DataSource getDataSource(){
        return ds;
    }
}

DBUTilsDao

package com.yue.chapter10;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import java.sql.SQLException;
import java.util.List;

public class DBUTilsDao {
    public boolean insert(User user) throws SQLException {
        QueryRunner queryRunner = new QueryRunner(C3p0Utils.getDataSource());
        String sql = "insert into user(name,password) values(?,?)";
        int count = queryRunner.update(sql,user.getName(),user.getPassword());
        if(count > 0 ){
            return true;
        }
        return false;
    }
    public List<User> findAll() throws SQLException {
        QueryRunner queryRunner = new QueryRunner(C3p0Utils.getDataSource());
        String sql = "select * from user";
        List<User> query = queryRunner.query(sql, new BeanListHandler<User>(User.class));
        return query;
    }
    public User findById(int id) throws SQLException {
        QueryRunner queryRunner = new QueryRunner(C3p0Utils.getDataSource());
        String sql = "select * from user where id=?";
        User query = queryRunner.query(sql, new BeanHandler<User>(User.class), id);
        return query;
    }
    public Boolean update(User user)throws SQLException{
        QueryRunner queryRunner = new QueryRunner(C3p0Utils.getDataSource());
        String sql = "update user set name = ?,password = ? where id = ?";
        int i = queryRunner.update(sql, user.getName(), user.getPassword(), user.getId());
        if(i>0){
            return true;
        }
        return false;
    }
    public boolean delete (int id) throws SQLException {
        QueryRunner queryRunner = new QueryRunner(C3p0Utils.getDataSource());
        String sql = "delete from user where id =?";
        int i = queryRunner.update(sql, id);
        if(i>0){
            return true;
        }
        return false;
    }
}

User

package com.yue.chapter10;

public class User {
    private int id;
    private String name;
    private String password;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

c3p0-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
	<default-config>
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">
     		jdbc:mysql://localhost:3306/yun6
     	</property>
		<property name="user">root</property>
		<property name="password">root</property>
		<property name="checkoutTimeout">30000</property>
		<property name="initialPoolSize">10</property>
		<property name="maxIdleTime">30</property>
		<property name="maxPoolSize">100</property>
		<property name="minPoolSize">10</property>
		<property name="maxStatements">200</property>
	</default-config> 
	<named-config name="itcast">
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">
           	jdbc:mysql://localhost:3306/yun6
        </property>
		<property name="user">root</property>
		<property name="password">root</property>
		<property name="initialPoolSize">5</property>
		<property name="maxPoolSize">15</property>
	</named-config>
</c3p0-config>

测试的代码

public class deleteTest {
    private static DBUTilsDao dbuTilsDao  = new DBUTilsDao();
    private static void testInset() throws SQLException {
        boolean delete = dbuTilsDao.delete(2);
        System.out.println(delete);
    }

    public static void main(String[] args) throws SQLException {
        testInset();
    }
}
public class findAllTest {
    private static DBUTilsDao dbuTilsDao  = new DBUTilsDao();
    private static void testInset() throws SQLException {
        List<User> all = dbuTilsDao.findAll();
        System.out.println(all.size());
    }

    public static void main(String[] args) throws SQLException {
        testInset();
    }
}
public class findByIdTest {
    private static DBUTilsDao dbuTilsDao  = new DBUTilsDao();
    private static void testInset() throws SQLException {
        User user = dbuTilsDao.findById(2);
        System.out.println(user.getName()+user.getPassword());
    }

    public static void main(String[] args) throws SQLException {
        testInset();
    }
}
public class InsertTest {
    private static DBUTilsDao dbuTilsDao  = new DBUTilsDao();
    private static void testInset() throws SQLException {
        User user = new User();
        user.setName("xi");
        user.setPassword("156462");
        boolean insert = dbuTilsDao.insert(user);
        System.out.println(insert);
    }

    public static void main(String[] args) throws SQLException {
        testInset();
    }
}
public class updateTest {
    private static DBUTilsDao dbuTilsDao  = new DBUTilsDao();
    private static void testInset() throws SQLException {
        User user = new User();
        user.setId(2);
        user.setName("ooo");
        user.setPassword("0000000");
        dbuTilsDao.update(user);
    }

    public static void main(String[] args) throws SQLException {
        testInset();
    }
}

利用jsp model 完成注册

准备jsp页面：register.jsp注册页面；loginSuccess.jsp注册成功要跳转的页面
准别javabean:
UserBean:封装注册的基本参数,包含用户名，密码，邮箱
RegisterFormBean:封装注册参数，包含用户名密码确认密码邮箱；服务段校验：比如用户名是否为null，用户名是否是重复的，前端校验：校验数据是否完整，比如格式是否规范
数据库模拟文件：
controllerServlet文件处理注册请求

loginSuccess.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>login successfully</title>
    <style type="text/css">
        #main{
            width: 500px;
            height: auto;
        }
        #main div {
            width: 200px;
            height: auto;
        }
        ul{
            padding-top: 1px;
            padding-left: 1px;
            list-style: none;
        }
    </style>
</head>
<body>
<%
if (session.getAttribute("userBean") == null) {
%>
<jsp:forward page="register.jsp"/>
<%
return;
    }
%>
<div id="main">
    <div id="welcome">
    恭喜你登陆成功
    </div>
    <hr/>
    <div>您的信息</div>
    <div>
        <ul>
            <li>您的名字：${userBean.name}</li>
            <li>您的邮箱：${userBean.email}</li>
        </ul>
    </div>
</div>
</body>
</html>

register.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>用户注册</title>
    <style type="text/css">
        h3{
            margin-left: 100px;
        }
        #outer{
            width: 750px;
        }
        span{
            color: #ff0000;
        }
        div{
            height: 20px;
            margin-bottom: 10px;
        }
        .ch{
            width: 80px;
            text-align: right;
            float: left;
        }
        .ip{
            width: 500px;
            float: left;
        }
        .ip>input{
            margin-right: 20px;
        }
        #bt{
            margin-left: 50px;
        }
        #bt>input{
            margin-right: 30px;
        }
    </style>
</head>
<body>
<form action="ControllerServlet" method="post">
    <h3>用户注册</h3>
    <div id="outer">
        <div>
            <div class="ch">姓名：</div>
            <div class="ip">
                <input type="text" name="name" value="${formBean.name}">
                <span>${formBean.errors.name}${DBMes}</span>
            </div>
            <div>
                <div class="ch">密码：</div>
                <div class="ip">
                    <input type="text" name="password">
                    <span>${formBean.errors.password}</span>
                </div>
            </div>
            <div>
                <div class="ch">确认密码：</div>
                <div class="ip">
                    <input type="text" name="password2">
                    <span>${formBean.errors.password2}</span>
                </div>
            </div>
            <div>
                <div class="ch">邮箱：</div>
                <div class="ip">
                    <input type="text" name="email" value="${formBean.email}">
                    <span>${formBean.errors.email}</span>
                </div>
            </div>
            <div>
                <div id="bt">
                    <input type="reset" value="重置">
                    <input type="submit" value="注册">
                </div>
            </div>
        </div>
    </div>

</form>

</body>
</html>

ControllerServlet

package com.yue.chapter11;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class ControllerServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取用户信息注册时的参数0
        resp.setContentType("text/html;charset=utf-8");
        req.setCharacterEncoding("utf-8");
        String name = req.getParameter("name");
        String password = req.getParameter("password");
        String password2 = req.getParameter("password2");
        String email = req.getParameter("email");
        //将获取的参数封装到RegisterFormBean
        RegisterFormBean formBean = new RegisterFormBean();
        formBean.setEmail(email);
        formBean.setName(name);
        formBean.setPassword(password);
        formBean.setPassword2(password2);
        if(!formBean.validate()){
            req.setAttribute("formBean" ,formBean);
            req.getRequestDispatcher("/register.jsp").forward(req,resp);
            return;
        }
        //参数填写符合要求，将数据封装到UserBean中
        UserBean userBean = new UserBean();
        userBean.setName(name);
        userBean.setEmail(email);
        userBean.setPassword(password);
        //调用DBUtil的insertUser()方法，并返回一个boolean的类型
        boolean b = DBUtil.getInstance().insertUser(userBean);
        if(!b){
            req.setAttribute("DBMes","您注册的用户已存在");
            req.setAttribute("formBean",formBean);
            req.getRequestDispatcher("/register.jsp").forward(req,resp);
            return;
        }
        resp.getWriter().println("恭喜您注册成功，三秒后自动跳转");
        //将成功注册的用户添加到Session中
        req.getSession().setAttribute("userBean",userBean);
        resp.setHeader("refresh" ,"3;url=loginSuccess.jsp");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

DBUtil

package com.yue.chapter11;

import java.util.HashMap;

public class DBUtil {
    private static DBUtil instance = new DBUtil();
    public static DBUtil getInstance(){
        return instance;
    }
    //定义user的集合
    private HashMap<String,UserBean> users = new HashMap<String,UserBean>();
    private DBUtil(){
        //向数据库中添加数据
        UserBean userBean = new UserBean();
        userBean.setName("Jack");
        userBean.setPassword("1123456");
        userBean.setEmail("jack@456.afdkl");
        users.put("Jack",userBean);
        UserBean userBean1 = new UserBean();
        userBean1.setName("Jack");
        userBean1.setPassword("1123456");
        userBean1.setEmail("jack@456.afdkl");
        users.put("Jack",userBean1);
    }
    //获取数据库中的数据
    public UserBean getUser(String userName){
        UserBean userBean = users.get(userName);
        return userBean;
    }
    //向数据库中添加数据
    public boolean insertUser(UserBean userBean){
        if(userBean ==null){
            return false;
        }
        String name = userBean.getName();
        if(users.get(name)!=null){
            return false;
        }
        users.put(name,userBean);
        return true;
    }
}

RegisterFormBean

package com.yue.chapter11;

import java.util.HashMap;
import java.util.Map;

public class RegisterFormBean {
    private Map<String ,String> errors = new HashMap<String,String>();
    private String name;
    private String password;
    private String password2;
    private String email;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getPassword2() {
        return password2;
    }

    public void setPassword2(String password2) {
        this.password2 = password2;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
    String regx ="[a-zA-z0-9_-]+@[a-zA-z0-9_-]+(\\.[a-zA-z0-9_-]+)+";
    public boolean validate(){
        boolean flag = true;
        if(name == null || name.trim().equals("")){
            errors.put("name","请输入姓名");
            flag = false;
        }
        if(password == null || password.trim().equals("")){
            errors.put("password","请输入密码");
            flag = false;
        }else if(password.length()>12 || password.length()<6){
            errors.put("password","请输入6-12位密码");
            flag = false;
        }
        if(password != null && !password.equals(password2)){
            errors.put("password2","两次密码不一致");
            flag = false;
        }
        if(email == null || email.trim().equals("")){
            errors.put("email","请输入邮箱");
            flag = false;
        }else if(!email.matches(regx)){
            errors.put("email","邮箱格式不对");
            flag = false;
        }
        return false;
        }

    public Map<String, String> getErrors() {
        return errors;
    }

    public void setErrors(String err,String errMsg) {
        if(err!=null&&errMsg!=null){
            errors.put(err,errMsg);
        }
    }
}

UserBean

package com.yue.chapter11;

public class UserBean {
    private String  name;
    private String password;
    private String email;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}