web项目log日志查看分析->流程理解
1.DEBUG [2017-07-10 11:38:41,705][] org.springframework.web.servlet.DispatcherServlet:865 - DispatcherServlet with name 'dispatcherServlet' processing POST request for [/profit/queryProfitAccountList]
注:spring mvc的的DispatcherServlet dispatcherservlet会日志打印传进来的每个请求的url和http方法,并日志debug输出打印
2.AbstractHandlerMethodMapping dispatcherservlet处理分发请求后,当然就要handlermapping查找controller的方法了,如下打印:
2.DEBUG [2017-07-10 11:38:41,705][] org.springframework.web.servlet.handler.AbstractHandlerMethodMapping:310 - Looking up handler method for path /profit/queryProfitAccountList
debug打印“Looking up handler method for path /profit/queryProfitAccountList
3.DEBUG [2017-07-10 11:38:41,705][] org.springframework.web.servlet.handler.AbstractHandlerMethodMapping:317 - Returning handler method [public java.util.Map<java.lang.String, java.lang.Object> com.pingan.property.icore.pap.aggregation.profit.controller.ProfitController.queryProfitAccounts(com.pingan.property.icore.pap.aggregation.profit.dto.QueryProfitAccountReqDTO)]
AbstractHandlerMethodMapping
handlermapping查找到url对应的controller和方法,并log打印出来controller类名和处理方法名,并打印出整个方法的形参和返回值 4.DEBUG [2017-07-10 11:38:41,706][] org.springframework.beans.factory.support.AbstractBeanFactory:251 - Returning cached instance of singleton bean 'profitController'
找到controller了(即handler),那么就从spring ioc里拿出来这个单例的bean呗,就有了AbstractBeanFactory类去取bean。 5.接下来就要调用
AbstractMessageConverterMethodArgumentResolver进行入参的json格式转换了。
将json string转为DTO,
再返回输出的时候将DTO转换为json字符串
DEBUG [2017-07-10 11:38:41,719][] org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver:197 - Read [class com.pingan.property.icore.pap.aggregation.profit.dto.QueryProfitAccountReqDTO] as "application/json;charset=UTF-8" with [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@19200eab]
6.马上要sql语句操纵的时候,
org.mybatis.spring.SqlSessionUtils SqlSessionUtils
mybatis会打印创建sqlsession的log
DEBUG [2017-07-10 11:38:41,719][] org.mybatis.spring.SqlSessionUtils:97 - Creating a new SqlSession 7.然后可以mybatis设置sqlsession是否同步
DEBUG [2017-07-10 11:38:41,719][] org.mybatis.spring.SqlSessionUtils:148 - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@391b61a4] was not registered for synchronization because synchronization is not active
8.创建sqlsession后,mybatis就要从
org.springframework.jdbc.datasource.DataSourceUtils
datasource里取出一个jdbc connection了
DEBUG [2017-07-10 11:38:41,720][] org.springframework.jdbc.datasource.DataSourceUtils:110 - Fetching JDBC Connection from DataSource 9.jdbc connection拿出来后,就要对connection进行事务处理判断了。
spring 默认也会打印出来关于这个connection的数据库连接串信息
DEBUG [2017-07-10 11:38:41,723][] org.mybatis.spring.transaction.SpringManagedTransaction:87 - JDBC Connection [74708194, URL=jdbc:oracle:thin:@t0eshop.dbstg.paic.com.cn:1597:t0eshop, UserName=PAPOPR, Oracle JDBC driver] will not be managed by Spring
10.spring jdbc connection拿到后,也进行了事务判断,接下来mybatis就要打印sql语句log了。
mybatis负责打印sql语句log的用到的类是org.apache.ibatis.logging.jdbc.BaseJdbcLogger。
DEBUG [2017-07-10 11:38:41,724][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Preparing: SELECT uuid FROM uid_cert_mobile WHERE mobile_no=? AND is_valid = ?
DEBUG [2017-07-10 11:38:41,724][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Parameters: 13565050505(String), Y(String)
DEBUG [2017-07-10 11:38:41,727][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - <== Total: 1 11.sql局域执行完,mybatis打印log显示关闭这条connection
org.mybatis.spring.SqlSessionUtils
DEBUG [2017-07-10 11:38:41,728][] org.mybatis.spring.SqlSessionUtils:191 - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@391b61a4]
12.实际mybatis关闭sqlsession是调用spring jdbc的return connection到datsource
org.springframework.jdbc.datasource.DataSourceUtils
DEBUG [2017-07-10 11:38:41,728][] org.springframework.jdbc.datasource.DataSourceUtils:327 - Returning JDBC Connection to DataSource
13.return完spring的jdbc connection给spring jdbc datasource后,就要统一返回dto转成成json字符串返回了啊。
又要用到spring mvc的
AbstractMessageConverterMethodProcessor。
注意:这里有个区别,一个是read一个是write。
read是在http request进来的时候将json字符串转换为dto并作为参数传给controller。
write是controller返回dto后,将dto转换为json字符串,为write
DEBUG [2017-07-10 11:39:35,135][] org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor:234 - Written [{profitAccountList=[com.pingan.property.icore.pap.aggregation.profit.dto.ProfitAccountDTO@755c5763, com.pingan.property.icore.pap.aggregation.profit.dto.ProfitAccountDTO@a2bfab5, com.pingan.property.icore.pap.aggregation.profit.dto.ProfitAccountDTO@6bc29bbb]}] as "application/json" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@19200eab]
14.既然controller已处理完,且已转换为json,就要返回给dispatcherservlet 给modelandview了
DEBUG [2017-07-10 11:39:35,135][] org.springframework.web.servlet.DispatcherServlet:1044 - Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
15.请求处理完后,spring mvc的FrameworkServlet会打印出请求处理完的log语句。
至此,一个request请求完毕
DEBUG [2017-07-10 11:39:35,135][] org.springframework.web.servlet.FrameworkServlet:1000 - Successfully completed request
完整的log打印如下:
DEBUG [2017-07-10 11:39:30,791][] org.springframework.web.servlet.DispatcherServlet:865 - DispatcherServlet with name 'dispatcherServlet' processing POST request for [/profit/queryProfitAccountList]
DEBUG [2017-07-10 11:39:30,791][] org.springframework.web.servlet.handler.AbstractHandlerMethodMapping:310 - Looking up handler method for path /profit/queryProfitAccountList
DEBUG [2017-07-10 11:39:30,791][] org.springframework.web.servlet.handler.AbstractHandlerMethodMapping:317 - Returning handler method [public java.util.Map<java.lang.String, java.lang.Object> com.pingan.property.icore.pap.aggregation.profit.controller.ProfitController.queryProfitAccounts(com.pingan.property.icore.pap.aggregation.profit.dto.QueryProfitAccountReqDTO)]
DEBUG [2017-07-10 11:39:30,791][] org.springframework.beans.factory.support.AbstractBeanFactory:251 - Returning cached instance of singleton bean 'profitController'
INFO [2017-07-10 11:39:30,792][] com.pingan.property.icore.pap.access.interceptor.EntranceInterceptor:46 - *************** EntranceInterceptor preHandle() begin ****************
INFO [2017-07-10 11:39:30,793][] com.pingan.property.icore.pap.access.um.controller.UMApiAuthService:36 - pap->properties读取到umpwd is3mxVy95H
INFO [2017-07-10 11:39:30,793][] com.pingan.property.icore.pap.access.interceptor.EntranceInterceptor:115 - umAuthUser authorization header is: Basic Vl9QQTAxM19QQTE4X0VNQUxMOjdrSjV0ZkUy
INFO [2017-07-10 11:39:30,793][] com.pingan.property.icore.pap.access.interceptor.EntranceInterceptor:118 - umAuthUser decoded namePwd is: V_PA013_PA18_EMALL:7kJ5tfE2
INFO [2017-07-10 11:39:30,794][] com.pingan.property.icore.pap.access.um.controller.GuavaCachedService:60 - key : V_PA013_PA18_EMALL:7kJ5tfE2,在缓存中不存在,需要调用外部接口获取值
INFO [2017-07-10 11:39:30,794][] com.pingan.property.icore.pap.access.um.controller.GuavaCachedService:65 - userName = V_PA013_PA18_EMALL, passwd = 7kJ5tfE2
INFO [2017-07-10 11:39:30,803][] com.pingan.property.icore.pap.access.interceptor.EntranceInterceptor:125 - pap->用户的cookie : 1
INFO [2017-07-10 11:39:30,803][] com.pingan.property.icore.pap.access.interceptor.EntranceInterceptor:63 - pap-> um switch->1
INFO [2017-07-10 11:39:30,803][] com.pingan.property.icore.pap.access.interceptor.EntranceInterceptor:65 - ************** EntranceInterceptor preHandle() end*********************
DEBUG [2017-07-10 11:39:30,803][] org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver:197 - Read [class com.pingan.property.icore.pap.aggregation.profit.dto.QueryProfitAccountReqDTO] as "application/json;charset=UTF-8" with [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@19200eab]
INFO [2017-07-10 11:39:30,804][] com.pingan.property.icore.pap.aggregation.profit.controller.ProfitController:75 - 查询权益账户信息传入参数:req=QueryProfitAccountReqDTO [mobileNo=13565050505, profitType=null, uuid=null]
DEBUG [2017-07-10 11:39:30,804][] org.mybatis.spring.SqlSessionUtils:97 - Creating a new SqlSession
DEBUG [2017-07-10 11:39:30,804][] org.mybatis.spring.SqlSessionUtils:148 - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@457c4787] was not registered for synchronization because synchronization is not active
DEBUG [2017-07-10 11:39:30,805][] org.springframework.jdbc.datasource.DataSourceUtils:110 - Fetching JDBC Connection from DataSource
DEBUG [2017-07-10 11:39:30,808][] org.mybatis.spring.transaction.SpringManagedTransaction:87 - JDBC Connection [1699135185, URL=jdbc:oracle:thin:@t0eshop.dbstg.paic.com.cn:1597:t0eshop, UserName=PAPOPR, Oracle JDBC driver] will not be managed by Spring
DEBUG [2017-07-10 11:39:30,808][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Preparing: SELECT uuid FROM uid_cert_mobile WHERE mobile_no=? AND is_valid = ?
DEBUG [2017-07-10 11:39:30,809][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Parameters: 13565050505(String), Y(String)
DEBUG [2017-07-10 11:39:30,812][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - <== Total: 1
DEBUG [2017-07-10 11:39:30,813][] org.mybatis.spring.SqlSessionUtils:191 - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@457c4787]
DEBUG [2017-07-10 11:39:30,813][] org.springframework.jdbc.datasource.DataSourceUtils:327 - Returning JDBC Connection to DataSource
INFO [2017-07-10 11:39:30,813][] com.pingan.property.icore.pap.common.util.PAPLogger:77 - 查询权益账户信息传入参数:req=com.pingan.property.icore.pap.profit.dto.AccountDTO@3cf11332
INFO [2017-07-10 11:39:30,813][] com.pingan.property.icore.pap.common.util.PAPLogger:77 - 查询权益账户信息传入参数:req=com.pingan.property.icore.pap.profit.dto.AccountDTO@3cf11332
DEBUG [2017-07-10 11:39:30,813][] org.mybatis.spring.SqlSessionUtils:97 - Creating a new SqlSession
DEBUG [2017-07-10 11:39:30,814][] org.mybatis.spring.SqlSessionUtils:148 - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1a4ea0e6] was not registered for synchronization because synchronization is not active
DEBUG [2017-07-10 11:39:30,814][] org.springframework.jdbc.datasource.DataSourceUtils:110 - Fetching JDBC Connection from DataSource
DEBUG [2017-07-10 11:39:30,817][] org.mybatis.spring.transaction.SpringManagedTransaction:87 - JDBC Connection [1026133079, URL=jdbc:oracle:thin:@t0eshop.dbstg.paic.com.cn:1597:t0eshop, UserName=PAPOPR, Oracle JDBC driver] will not be managed by Spring
DEBUG [2017-07-10 11:39:30,818][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Preparing: select ID_PROFIT_ACCOUNT, UUID, PROFIT_TYPE, AVAILABLE_NUM, HISTORY_NUM, CREATED_DATE, CREATED_BY, UPDATED_DATE, UPDATED_BY, IS_VALID from PROFIT_ACCOUNT where UUID = ? and PROFIT_TYPE = ? and IS_VALID = 'Y'
DEBUG [2017-07-10 11:39:30,818][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Parameters: 52007A8473E72EE6E054000B5DE0B7FC(String), 1(String)
DEBUG [2017-07-10 11:39:30,822][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - <== Total: 1
DEBUG [2017-07-10 11:39:30,822][] org.mybatis.spring.SqlSessionUtils:191 - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1a4ea0e6]
DEBUG [2017-07-10 11:39:30,822][] org.springframework.jdbc.datasource.DataSourceUtils:327 - Returning JDBC Connection to DataSource
INFO [2017-07-10 11:39:30,822][] com.pingan.property.icore.pap.common.util.PAPLogger:77 - 查询权益账户信息传入参数:req=com.pingan.property.icore.pap.profit.dto.AccountDTO@3cf11332
DEBUG [2017-07-10 11:39:30,823][] org.mybatis.spring.SqlSessionUtils:97 - Creating a new SqlSession
DEBUG [2017-07-10 11:39:30,823][] org.mybatis.spring.SqlSessionUtils:148 - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@6dc91d15] was not registered for synchronization because synchronization is not active
DEBUG [2017-07-10 11:39:30,823][] org.springframework.jdbc.datasource.DataSourceUtils:110 - Fetching JDBC Connection from DataSource
DEBUG [2017-07-10 11:39:30,826][] org.mybatis.spring.transaction.SpringManagedTransaction:87 - JDBC Connection [1502997277, URL=jdbc:oracle:thin:@t0eshop.dbstg.paic.com.cn:1597:t0eshop, UserName=PAPOPR, Oracle JDBC driver] will not be managed by Spring
DEBUG [2017-07-10 11:39:30,827][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Preparing: select ID_PROFIT_ACCOUNT, UUID, PROFIT_TYPE, AVAILABLE_NUM, HISTORY_NUM, CREATED_DATE, CREATED_BY, UPDATED_DATE, UPDATED_BY, IS_VALID from PROFIT_ACCOUNT where UUID = ? and PROFIT_TYPE = ? and IS_VALID = 'Y'
DEBUG [2017-07-10 11:39:30,827][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Parameters: 52007A8473E72EE6E054000B5DE0B7FC(String), 2(String)
DEBUG [2017-07-10 11:39:30,831][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - <== Total: 1
DEBUG [2017-07-10 11:39:30,831][] org.mybatis.spring.SqlSessionUtils:191 - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@6dc91d15]
DEBUG [2017-07-10 11:39:30,831][] org.springframework.jdbc.datasource.DataSourceUtils:327 - Returning JDBC Connection to DataSource
INFO [2017-07-10 11:39:30,832][] com.pingan.property.icore.pap.common.util.PAPLogger:77 - 查询权益账户信息传入参数:req=com.pingan.property.icore.pap.profit.dto.AccountDTO@3cf11332
DEBUG [2017-07-10 11:39:30,832][] org.mybatis.spring.SqlSessionUtils:97 - Creating a new SqlSession
DEBUG [2017-07-10 11:39:30,832][] org.mybatis.spring.SqlSessionUtils:148 - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@36332959] was not registered for synchronization because synchronization is not active
DEBUG [2017-07-10 11:39:30,832][] org.springframework.jdbc.datasource.DataSourceUtils:110 - Fetching JDBC Connection from DataSource
DEBUG [2017-07-10 11:39:30,836][] org.mybatis.spring.transaction.SpringManagedTransaction:87 - JDBC Connection [1200181500, URL=jdbc:oracle:thin:@t0eshop.dbstg.paic.com.cn:1597:t0eshop, UserName=PAPOPR, Oracle JDBC driver] will not be managed by Spring
DEBUG [2017-07-10 11:39:30,836][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Preparing: select ID_PROFIT_GP_ACCOUNT, UUID, AVAILABLE_NUM, HISTORY_NUM, CREATED_DATE, CREATED_BY, UPDATED_DATE, UPDATED_BY, IS_VALID from PROFIT_GP_ACCOUNT where UUID = ? and IS_VALID = 'Y'
DEBUG [2017-07-10 11:39:30,836][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - ==> Parameters: 52007A8473E72EE6E054000B5DE0B7FC(String)
DEBUG [2017-07-10 11:39:30,840][] org.apache.ibatis.logging.jdbc.BaseJdbcLogger:181 - <== Total: 1
DEBUG [2017-07-10 11:39:30,840][] org.mybatis.spring.SqlSessionUtils:191 - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@36332959]
DEBUG [2017-07-10 11:39:30,841][] org.springframework.jdbc.datasource.DataSourceUtils:327 - Returning JDBC Connection to DataSource
DEBUG [2017-07-10 11:39:30,841][] org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor:234 - Written [{profitAccountList=[com.pingan.property.icore.pap.aggregation.profit.dto.ProfitAccountDTO@620ddcad, com.pingan.property.icore.pap.aggregation.profit.dto.ProfitAccountDTO@14b61ef2, com.pingan.property.icore.pap.aggregation.profit.dto.ProfitAccountDTO@3b6084dc]}] as "application/json" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@19200eab]
DEBUG [2017-07-10 11:39:30,842][] org.springframework.web.servlet.DispatcherServlet:1044 - Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
DEBUG [2017-07-10 11:39:30,842][] org.springframework.web.servlet.FrameworkServlet:1000 - Successfully completed request
web项目log日志查看分析->流程理解的更多相关文章
- iOS及时log日志查看工具 (iConsole)
github下载地址:https://github.com/nicklockwood/iConsole 偶然看到的一个iOS及时log日志查看工具,通过该工具,我们可以在任何想看日志的时候,通过手势呼 ...
- 64位系统web项目导出excel问题分析及解决方法汇总
最近在web项目中做了一个导出Excel功能.在导出的时候报错:检索 COM 类工厂中 CLSID 为 {00024500-0000-0000-C000-000000000046} 的组件时失败. 一 ...
- web项目中日志管理工具的使用
在web项目中,很多时候会用到日志管理工具,常见的日志管理用具有:JDK logging(配置文件:logging.properties) 和log4j(配置文件:log4j.properties) ...
- web项目开启日志打印
原文链接:http://blog.csdn.net/qq_37936542/article/details/79045188 参考文章地址:点击打开链接,写的很清晰 一:导入log4j包或依赖 ...
- web项目Log4j日志输出路径配置问题
问题描述:一个web项目想在一个tomcat下运行多个实例(通过修改war包名称的实现),然后每个实例都将日志输出到tomcat的logs目录下实例名命名的文件夹下进行区分查看每个实例日志,要求通过尽 ...
- Android 项目Log日志输出优化
概述 Android开发过程中经常需要向控制台输出日志信息,有些人还在用Log.i(tag,msg)的形式或者system.out.println(msg)方式吗?本篇文章对日志信息输出进行优化,以达 ...
- web项目的日志打印位置设置
1, 若在项目中放logback.groovy文件(如: src/test/resource下),则日志会打印到控制台上. logback.groovy 内容如下: // // Built on Fr ...
- Ubuntu下的log日志查看器
1.lnav:Linux 下一个基于控制台的高级日志文件查看器 https://www.cnblogs.com/michealLang/p/9761886.html http://www.imooc. ...
- 腾讯云和阿里云部署web 项目tomcat 日志 中文变成问号
在部署项目到云上的时候,遇到了tomcat logs 日志中文变问号的问题,今天终于得到解决了 这是中文变成问号的的截图 打开到tomcat bin 目录的文件夹 找到catalina.sh 文件 ...
随机推荐
- codevs1163访问艺术馆(树形dp)
1163 访问艺术馆 时间限制: 1 s 空间限制: 128000 KB 题目等级 : 大师 Master 题目描述 Description 皮尔是一个出了名的盗画者,他经过数月的精心准备, ...
- [Swift通天遁地]三、手势与图表-(8)制作股市中常用的蜡烛图表
★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★➤微信公众号:山青咏芝(shanqingyongzhi)➤博客园地址:山青咏芝(https://www.cnblogs. ...
- Sqoop 产生背景(一)
Sqoop 的产生主要源于: 1.目前很多使用hadoop技术的企业,有大量的数据存储在传统关系型数据库中. 2.早期由于工具的缺乏,hadoop与传统数据库之间的数据传输非常困难. 1)传统数据库中 ...
- Java—解压zip文件
import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import ja ...
- (转)Vue 爬坑之路(四)—— 与 Vuex 的第一次接触
在 Vue.js 的项目中,如果项目结构简单, 父子组件之间的数据传递可以使用 props 或者 $emit 等方式 http://www.cnblogs.com/wisewrong/p/62660 ...
- 国内外知名IT科技博客
国内 1.36氪(www.36kr.com): 目前国内做的最风生水起的科技博客,以介绍国内外互联网创业新闻为主的博客网站,自己建立有36Tree互联网创业融投资社区.36氪的名字源于元素周期 表的第 ...
- [转][IPC通信]基于管道的popen和pclose函数
标准I/O函数库提供了popen函数,它启动另外一个进程去执行一个shell命令行. 这里我们称调用popen的进程为父进程,由popen启动的进程称为子进程. popen函数还创建一个管道用于父子进 ...
- [Windows Server 2012] 安装护卫神·主机管理系统
★ 欢迎来到[护卫神·V课堂],网站地址:http://v.huweishen.com★ 护卫神·V课堂 是护卫神旗下专业提供服务器教学视频的网站,每周更新视频.★ 本节我们将带领大家:安装护卫神·主 ...
- Java我来了
七天的C#集训,第一天接触Java,觉得很多相似的地方,尝试用eclipse码了几句(有些差别,毕竟没有写C#那么流畅),总体来说觉得还不错,对自己接下来要求是,更加熟练并且牢记Java的命令,更加深 ...
- Redis事物及锁的运用
redis与mysql事物比较如下: 下面是一个redis事物运用于买票的demo