前面两节我们完成了数据库层DAO层和业务逻辑层Service层的编写,接下来我们要编写前端交互层Web层。在这一层中,我们要将前面两层结合在一起,从而实现前端与后端的友好交互。Web层主要采用Restful规范+Spring MVC+bootstrap+jQuery的框架实现。
1 前端交互流程设计
一般情况下,在设计一个系统时,有以下几个方面:
- 产品经理采集用户需求
- 产品经理根据需求设计开发文档
- 前端工程师根据开发文档完成前端页面的开发
- 后端工程师根据开发文档完成后端业务逻辑的开发
对于我们这个秒杀系统,整体的交互流程如下图所示:
2 学习Restful接口设计
REST(英文:Representational State Transfer,简称REST),指的是一组架构约束条件和原则。满足这些约束条件和原则的应用程序或设计就是 RESTful。REST本身并没有创造新的技术、组件或服务,而隐藏在RESTful背后的理念就是使用Web的现有特征和能力, 更好地使用现有Web标准中的一些准则和约束。
知乎大神Ivony有句话说的好:
Restful就是用URL定位资源,用HTTP动词(GET,POST,DELETE,DETC)描述操作。
针对我们这个系统,API的URL设计如下图所示:
2.1 整合配置SpringMVC框架
在WEB-INF下的web.xml文件中配置DispatcherServlet,详细代码如下:
<!-- 配置DispatcherServlet -->
<servlet>
<servlet-name>seckill-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置Spring MVC需要加载的配置文件
spring-dao.xml,spring-service.xml,spring-web.xml
整合顺序:Mybatis->spring->springMVC(其实spring和springMVC不用整合,他们是在一起的)
-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/spring-*.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>seckill-dispatcher</servlet-name>
<!-- 默认匹配所有的请求 -->
<url-pattern>/</url-pattern>
</servlet-mapping>
接着在spring包下创建一个spring-web.xml,内容如下:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 配置SpringMVC -->
<!-- 1:开启SpringMVC注解模式 -->
<!-- 简化配置:
(1)自动注册DefaultAnnotationHandlerMapping,AnnotationMethodHandlerAdapter
(2)提供一系列功能:数据绑定,数字和日期的format,xml和json默认读写支持
-->
<mvc:annotation-driven/>
<!-- 2:静态资源默认servlet配置
(1):加入对静态资源的处理:js,gif,png
(2):允许使用"/"做整体映射
-->
<mvc:default-servlet-handler/>
<!-- 3:配置jsp,显示ViewResolver -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/jsp"/>
<property name="suffix" value=".jsp"/>
</bean>
<!-- 4:扫描web相关的bean -->
<context:component-scan base-package="org.seckill.web"/>
</beans>
2.2 使用SpringMVC实现Restful接口
在org.seckill包下创建一个web包用于放web层Controller开发的代码,在该包下创建一个SeckillController.java,内容如下:
package org.seckill.web;
import org.seckill.bean.Seckill;
import org.seckill.dto.SeckillResult;
import org.seckill.dto.Exposer;
import org.seckill.dto.SeckillExecution;
import org.seckill.enums.SeckillStateEnum;
import org.seckill.exception.RepeatKillException;
import org.seckill.exception.SeckillCloseException;
import org.seckill.exception.SeckillException;
import org.seckill.service.SeckillService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import java.util.Date;
import java.util.List;
@Controller //类似于@Service @Component 目的是将当前Controller放进Spring容器中
@RequestMapping("/seckill") //url:/模块/资源/{id}/细分
public class SeckillController {
private final Logger logger= LoggerFactory.getLogger(this.getClass());
@Autowired
private SeckillService seckillService;
@RequestMapping(name="/list",method= RequestMethod.GET)
public String list(Model model){
//获取列表页
List<Seckill> list= seckillService.getSeckillList();
model.addAttribute("list",list);
//list.jsp+model=ModelAndView
return "lsit"; // /WEB-INF/jsp/"list".jsp
}
@RequestMapping(value = "/{seckillId}/detail",method = RequestMethod.GET)
public String detail(@PathVariable("seckillId") Long seckillId, Model model){
if(seckillId==null){
return "redirect:/seckill/list";
}
Seckill seckill=seckillService.getById(seckillId);
if(seckill==null){
return "forward:/seckill/list";
}
model.addAttribute("seckill",seckill);
return "detail";
}
@RequestMapping(value = "/{seckillId}/exposer",
method = RequestMethod.POST,
produces = {"application/json;charset=UTF-8"})
@ResponseBody
public SeckillResult<Exposer> exposer(Long seckillId){
SeckillResult<Exposer> result;
try {
Exposer exposer=seckillService.exportSeckillUrl(seckillId);
result=new SeckillResult<Exposer>(true,exposer);
} catch (Exception e) {
logger.error(e.getMessage(),e);
result=new SeckillResult<Exposer>(false,e.getMessage());
}
return result;
}
@RequestMapping(value = "/{seckillId}/{md5}/execution",
method = RequestMethod.POST,
produces = "{application/json;charset=UTF-8}")
@ResponseBody
public SeckillResult<SeckillExecution> execute(@PathVariable("seckillId")Long seckillId,
@PathVariable("md5")String md5,
@CookieValue(value = "killPhone",required = false) Long phone) {
//springmvc valid
if (phone == null) {
return new SeckillResult<SeckillExecution>(false, "未注册");
}
SeckillResult<SeckillExecution> result;
try {
SeckillExecution execution = seckillService.executeSeckill(seckillId, phone, md5);
return new SeckillResult<SeckillExecution>(true, execution);
} catch (RepeatKillException e) {
SeckillExecution execution=new SeckillExecution(seckillId, SeckillStateEnum.REPEAT_KILL);
return new SeckillResult<SeckillExecution>(false,execution);
} catch (SeckillCloseException e) {
SeckillExecution execution=new SeckillExecution(seckillId,SeckillStateEnum.END);
return new SeckillResult<SeckillExecution>(false,execution);
} catch (SeckillException e) {
logger.error(e.getMessage(), e);
SeckillExecution execution=new SeckillExecution(seckillId,SeckillStateEnum.INNER_ERROR);
return new SeckillResult<SeckillExecution>(false,execution);
}
}
@RequestMapping(value = "/time/now",method = RequestMethod.GET)
public SeckillResult<Long> time(){
Date now=new Date();
return new SeckillResult<Long>(true, now.getTime());
}
}
其中用到了一个SeckillResult泛型类,他的作用是将所有的Ajax请求返回类型,全部封装成json数据,放在dto包下,详细代码如下:
package org.seckill.dto;
//封装json结果
public class SeckillResult<T> {
private boolean success;
private T data;
private String error;
public SeckillResult(boolean success, T data) {
this.success = success;
this.data = data;
}
public SeckillResult(boolean success, String error) {
this.success = success;
this.error = error;
}
public boolean isSuccess() {
return success;
}
public void setSuccess(boolean success) {
this.success = success;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
public String getError() {
return error;
}
public void setError(String error) {
this.error = error;
}
}
到此,Controller的开发任务完成,下面要进行前端页面的开发工作。
3 基于bootstrap开发页面结构
前端页面不再赘述,相关细节见代码注释
webapp/resources/script/seckill.js
//存放主要交互逻辑的js代码
// javascript 模块化(package.类.方法)
var seckill = {
//封装秒杀相关ajax的url
URL: {
now: function () {
return '/seckill/time/now';
},
exposer: function (seckillId) {
return '/seckill/' + seckillId + '/exposer';
},
execution: function (seckillId, md5) {
return '/seckill/' + seckillId + '/' + md5 + '/execution';
}
},
//验证手机号
validatePhone: function (phone) {
if (phone && phone.length == 11 && !isNaN(phone)) {
return true;//直接判断对象会看对象是否为空,空就是undefine就是false; isNaN 非数字返回true
} else {
return false;
}
},
//详情页秒杀逻辑
detail: {
//详情页初始化
init: function (params) {
//手机验证和登录,计时交互
//规划我们的交互流程
//在cookie中查找手机号
var userPhone = $.cookie('userPhone');
//验证手机号
if (!seckill.validatePhone(userPhone)) {
//绑定手机 控制输出
var killPhoneModal = $('#killPhoneModal');
killPhoneModal.modal({
show: true,//显示弹出层
backdrop: 'static',//禁止位置关闭
keyboard: false//关闭键盘事件
});
$('#killPhoneBtn').click(function () {
var inputPhone = $('#killPhoneKey').val();
console.log("inputPhone: " + inputPhone);
if (seckill.validatePhone(inputPhone)) {
//电话写入cookie(7天过期)
$.cookie('userPhone', inputPhone, {expires: 7, path: '/seckill'});
//验证通过 刷新页面
window.location.reload();
} else {
//todo 错误文案信息抽取到前端字典里
$('#killPhoneMessage').hide().html('<label class="label label-danger">手机号错误!</label>').show(300);
}
});
}
//已经登录
//计时交互
var startTime = params['startTime'];
var endTime = params['endTime'];
var seckillId = params['seckillId'];
$.get(seckill.URL.now(), {}, function (result) {
if (result && result['success']) {
var nowTime = result['data'];
//时间判断 计时交互
seckill.countDown(seckillId, nowTime, startTime, endTime);
} else {
console.log('result: ' + result);
alert('result: ' + result);
}
});
}
},
handlerSeckill: function (seckillId, node) {
//获取秒杀地址,控制显示器,执行秒杀
node.hide().html('<button class="btn btn-primary btn-lg" id="killBtn">开始秒杀</button>');
$.get(seckill.URL.exposer(seckillId), {}, function (result) {
//在回调函数种执行交互流程
if (result && result['success']) {
var exposer = result['data'];
if (exposer['exposed']) {
//开启秒杀
//获取秒杀地址
var md5 = exposer['md5'];
var killUrl = seckill.URL.execution(seckillId, md5);
console.log("killUrl: " + killUrl);
//绑定一次点击事件
$('#killBtn').one('click', function () {
//执行秒杀请求
//1.先禁用按钮
$(this).addClass('disabled');//,<-$(this)===('#killBtn')->
//2.发送秒杀请求执行秒杀
$.post(killUrl, {}, function (result) {
if (result && result['success']) {
var killResult = result['data'];
var state = killResult['state'];
var stateInfo = killResult['stateInfo'];
//显示秒杀结果
node.html('<span class="label label-success">' + stateInfo + '</span>');
}
});
});
node.show();
} else {
//未开启秒杀(浏览器计时偏差)
var now = exposer['now'];
var start = exposer['start'];
var end = exposer['end'];
seckill.countDown(seckillId, now, start, end);
}
} else {
console.log('result: ' + result);
}
});
},
countDown: function (seckillId, nowTime, startTime, endTime) {
console.log(seckillId + '_' + nowTime + '_' + startTime + '_' + endTime);
var seckillBox = $('#seckill-box');
if (nowTime > endTime) {
//秒杀结束
seckillBox.html('秒杀结束!');
} else if (nowTime < startTime) {
//秒杀未开始,计时事件绑定
var killTime = new Date(startTime + 1000);//todo 防止时间偏移
seckillBox.countdown(killTime, function (event) {
//时间格式
var format = event.strftime('秒杀倒计时: %D天 %H时 %M分 %S秒 ');
seckillBox.html(format);
}).on('finish.countdown', function () {
//时间完成后回调事件
//获取秒杀地址,控制现实逻辑,执行秒杀
console.log('______fininsh.countdown');
seckill.handlerSeckill(seckillId, seckillBox);
});
} else {
//秒杀开始
seckill.handlerSeckill(seckillId, seckillBox);
}
}
}
webapp/WEB-INF/jsp/common/head.jsp
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta charset="utf-8">
<!-- 新 Bootstrap 核心 CSS 文件 -->
<link href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet">
<!-- 可选的Bootstrap主题文件(一般不使用) -->
<link href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap-theme.min.css" rel="stylesheet">
<!-- HTML5 Shim 和 Respond.js 用于让 IE8 支持 HTML5元素和媒体查询 -->
<!-- 注意: 如果通过 file:// 引入 Respond.js 文件,则该文件无法起效果 -->
<!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js"></script>
<script src="https://oss.maxcdn.com/libs/respond.js/1.3.0/respond.min.js"></script>
<![endif]-->
webapp/WEB-INF/jsp/common/tag.jsp
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
webapp/WEB-INF/jsp/list.jsp
<%@page contentType="text/html; charset=UTF-8" language="java" %>
<%@include file="common/tag.jsp"%>
<!DOCTYPE html>
<html>
<head>
<title>秒杀商品列表</title>
<%@include file="common/head.jsp" %>
</head>
<body>
<div class="container">
<div class="panel panel-default">
<div class="panel-heading text-center">
<h2>秒杀列表</h2>
</div>
<div class="panel-body">
<table class="table table-hover">
<thead>
<tr>
<th>名称</th>
<th>库存</th>
<th>开始时间</th>
<th>结束时间</th>
<th>创建时间</th>
<th>详情页</th>
</tr>
</thead>
<tbody>
<c:forEach items="${list}" var="sk">
<tr>
<td>${sk.name}</td>
<td>${sk.number}</td>
<td>
<fmt:formatDate value="${sk.startTime}" pattern="yyyy-MM-dd HH:mm:ss" />
</td>
<td>
<fmt:formatDate value="${sk.endTime}" pattern="yyyy-MM-dd HH:mm:ss" />
</td>
<td>
<fmt:formatDate value="${sk.createTime}" pattern="yyyy-MM-dd HH:mm:ss" />
</td>
<td><a class="btn btn-info" href="/seckill/${sk.seckillId}/detail" target="_blank">详情</a></td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
<!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->
<script src="http://apps.bdimg.com/libs/jquery/2.0.0/jquery.min.js"></script>
<!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
<script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</body>
</html>
webapp/WEB-INF/jsp/detail.jsp
<%@page contentType="text/html; charset=UTF-8" language="java" %>
<%@include file="common/tag.jsp" %>
<!DOCTYPE html>
<html>
<head>
<title>秒杀详情页</title>
<%@include file="common/head.jsp" %>
</head>
<body>
<div class="container">
<div class="panel panel-default text-center">
<div class="pannel-heading">
<h1>${seckill.name}</h1>
</div>
<div class="panel-body">
<h2 class="text-danger">
<%--显示time图标--%>
<span class="glyphicon glyphicon-time"></span>
<%--展示倒计时--%>
<span class="glyphicon" id="seckill-box"></span>
</h2>
</div>
</div>
</div>
<%--登录弹出层 输入电话--%>
<div id="killPhoneModal" class="modal fade">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<h3 class="modal-title text-center">
<span class="glyphicon glyphicon-phone"> </span>秒杀电话:
</h3>
</div>
<div class="modal-body">
<div class="row">
<div class="col-xs-8 col-xs-offset-2">
<input type="text" name="killPhone" id="killPhoneKey"
placeholder="填写手机号^o^" class="form-control">
</div>
</div>
</div>
<div class="modal-footer">
<%--验证信息--%>
<span id="killPhoneMessage" class="glyphicon"> </span>
<button type="button" id="killPhoneBtn" class="btn btn-success">
<span class="glyphicon glyphicon-phone"></span>
Submit
</button>
</div>
</div>
</div>
</div>
</body>
<%--jQery文件,务必在bootstrap.min.js之前引入--%>
<script src="http://apps.bdimg.com/libs/jquery/2.0.0/jquery.min.js"></script>
<script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<%--使用CDN 获取公共js http://www.bootcdn.cn/--%>
<%--jQuery Cookie操作插件--%>
<script src="http://cdn.bootcss.com/jquery-cookie/1.4.1/jquery.cookie.min.js"></script>
<%--jQuery countDown倒计时插件--%>
<script src="http://cdn.bootcss.com/jquery.countdown/2.1.0/jquery.countdown.min.js"></script>
<script src="/resource/script/seckill.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
//使用EL表达式传入参数
seckill.detail.init({
seckillId:${seckill.seckillId},
startTime:${seckill.startTime.time},//毫秒
endTime:${seckill.endTime.time}
});
})
</script>
</html>
至此,Web层的编写已经完成,整个秒杀系统也已完成。
下一节进行高并发的优化及实现。