秒杀系统-web

 秒杀系统Web层主要涉及前端交互设计、Restful:url满足Restful设计规范、Spring MVC、bootstrap+jquery这四个方面的开发。秒杀系统的前端交互流程设计如下图6-3所示。

整合配置Spring MVC框架：
在web.xml中进行我们前端控制器DispatcherServlet的配置，配置springMVC需要加载的配置文件spring-dao.xml,spring-service.xml和spring-web.xml，详细配置如下。
web.xml：
<servlet>
    <servlet-name>seckill-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
         <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>
     <url-pattern>/</url-pattern>
</servlet-mapping>
spring-web.xml：
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
    <mvc:annotation-driven/>
    <mvc:default-servlet-handler/>
    <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>
    <context:component-scan base-package="org.seckill.web"/>
</beans>
完成Spring MVC的相关配置后，接下来就要基于Restful接口实现项目中的Controller开发。Controller中的每一个方法都对应我们系统中的一个资源URL，其设计应该遵循Restful接口的设计风格。在web包下创建一个SeckillController.java，内容如表6-11所示。

SeckillController.java：
@Controller
@RequestMapping("/seckill")
public class SeckillController {
    private final Logger logger = LoggerFactory.getLogger(this.getClass());
    @Autowired
    private SeckillService seckillService;
    @RequestMapping(value = "/list", method = RequestMethod.GET)
    public String list(Model model) {
        List<Seckill> list = seckillService.getSeckillList();
        model.addAttribute("list", list);
        //list.jsp + model = ModelAndView
        return "list";
    }
    @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(@PathVariable 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.executeSeckillProcedure(seckillId, phone, md5);
            return new SeckillResult<SeckillExecution>(true,execution);
        } catch (RepeatKillException e) {
            SeckillExecution execution = new SeckillExecution(seckillId, SeckillStatEnum.REPEAT_KILL);
            return new SeckillResult<SeckillExecution>(true,execution);
        } catch (SeckillCloseException e) {
           SeckillExecution execution = new SeckillExecution(seckillId, SeckillStatEnum.END);
            return new SeckillResult<SeckillExecution>(true,execution);
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            SeckillExecution execution = new SeckillExecution(seckillId, SeckillStatEnum.INNER_ERROR);
            return new SeckillResult<SeckillExecution>(true,execution);
        }
    }
    @RequestMapping(value = "/time/now",method = RequestMethod.GET)
    @ResponseBody
    public SeckillResult<Long> time(){
        Date now = new Date();
        return new SeckillResult(true,now.getTime());
    }
}
json数据的一个Vo类，即SeckillResult.java，在dto包中创建它，内容如下。
SeckillResult.java：
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;
    }
}