SecKillShop

主要实现一个商品秒杀的功能,梳理如何应对高并发的的技术的思路。

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所用技术

1.后端:SpringBoot、JSR303、MyBatis

2.前端:Thymeleaf、BootStrap、Jquery

3.中间件:RabbitMQ、Redis、Druid

项目搭建

1.搭建SpringBoot
1.添加maven
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>
2.集成thymeleaf
    1.导入依赖
        <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

    2.添加配置项:
      spring.thymeleaf.cache=false
      spring.thymeleaf.content-type=text/html
      spring.thymeleaf.enabled=true
      spring.thymeleaf.encoding=UTF-8
      spring.thymeleaf.mode=HTML5
      spring.thymeleaf.prefix=classpath:/templates/
      spring.thymeleaf.suffix=.html

    3.添加thymeleaf模版
      <!DOCTYPE HTML>
      <html xmlns:th="http://www.thymeleaf.org">
      <head>
        <title>hello</title>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
      </head>
      <body>
        <p th:text="'hello:'+${name}" ></p>
      </body>
      </html>
3.集成MyBatis
  1.添加依赖
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>1.3.1</version>
    </dependency>
  2.添加配置
    # mybatis
    mybatis.type-aliases-package=com.chengxiaoxiao.seckillshop.domain
    mybatis.configuration.map-underscore-to-camel-case=true
    mybatis.configuration.default-fetch-size=100
    mybatis.configuration.default-statement-timeout=3000
    mybatis.mapperLocations = classpath:com/chengxiaoxiao/seckillshop/dao/*.xml
4.添加MySql和Druid
    1.添加依赖
        <dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
          <groupId>com.alibaba</groupId>
          <artifactId>druid</artifactId>
          <version>1.0.5</version>
        </dependency>
    2.添加配置
        spring.datasource.url=jdbc:mysql://localhost:3306/miaosha?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT%2B8
        spring.datasource.username=root
        spring.datasource.password=123456
        spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
        spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
        spring.datasource.filters=stat
        spring.datasource.maxActive=2
        spring.datasource.initialSize=1
        spring.datasource.maxWait=60000
        spring.datasource.minIdle=1
        spring.datasource.timeBetweenEvictionRunsMillis=60000
        spring.datasource.minEvictableIdleTimeMillis=300000
        spring.datasource.validationQuery=select 'x'
        spring.datasource.testWhileIdle=true
        spring.datasource.testOnBorrow=false
        spring.datasource.testOnReturn=false
        spring.datasource.poolPreparedStatements=true
        spring.datasource.maxOpenPreparedStatements=20
        logging.leve.com.chengxiaoxiao.seckillshop=debug
5.安装redis
    1.官网:https://redis.io/download
   2.解压安装:
      1.解压文件:tar -zxvf redis-5.0.0.tar.gz
      2.移动到安装目录:mv redis-5.0.0 /usr/local/redis
      3.编译一下:make -j 4
        编译依赖gcc,安装如下:
          1.yum  install  gcc
          2.验证是否安装成功:rpm -qa |grep gcc
      4.make install
      5.修改配置文件
        vi redis.config
          1.修改可访问IP:修改bind 127.0.0.1  为bind 0.0.0.0
          2.修改后台启用:daemonize yes
          3.添加密码:requirepass
      6.运行:redis-server ./redis.conf
      7.重启:redis-cli     shutdown save
      8.命令行登录:auth password
      9.修改redis为系统服务
        1.cd utils
        2.  ./install_server.sh

        config:  /usr/local/redis/redis.config
        log:    /usr/local/redis/redis.log
        data:   /usr/local/redis/data
      10.查看后台进程是否存在
        1.查看进程:ps -ef |grep redis
        2.端口是否在监听:netstat -lntp | grep 6379
    3.添加依赖
          <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
          </dependency>

          <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.38</version>
          </dependency>
    4.添加配置:
          #redis            
          redis.host=192.168.220.128
          redis.port=6379
          redis.timeout=3
          redis.password=123456
          redis.poolMaxTotal=10
          redis.poolMaxIdle=10
          redis.poolMaxWait=3
6.防火墙开启端口
  1. 获取zone名称:firewall-cmd --get-active-zones
  2. 执行防火墙开启端口:firewall-cmd --zone=public --add-port=6379/tcp --permanent
  3. 重启防火墙:firewall-cmd --reload
  4. 查看端口是否开启:firewall-cmd --query-port=6379/tcp
  5. 查看服务:chkconfig --list | grep redis
7.添加集成MD5加密
  1. 添加依赖:
    <dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    </dependency>
    <dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.6</version>
    </dependency>

2.调用方法:

DigestUtils.md5Hex(src);
8.添加JSR303校验
1.添加依赖
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>
2.Controller中Vo上添加注解@Valid
3.自定义注解

1.添加注解类实现方法,注解类模板:


@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {IsMobileValidator.class })
public @interface IsMobile {
String message() default "手机号码格式错误";

Class<?>[] groups() default { };

Class<? extends Payload>[] payload() default { };

}


>2.添加注解校验规则类

public class IsMobileValidator implements ConstraintValidator<IsMobile, String> { @Override public void initialize(IsMobile constraintAnnotation) {

}

@Override
public boolean isValid(String s, ConstraintValidatorContext constraintValidatorContext) {
    return true;
}

}

2.使用
> Vo对应属性上增加注解,实现校验

#### 9.优化登录成功后,需要多次获取Cookie
> 1.自定义类,继承自WebMvcConfigurerAdapter,并添加@Configuration注解,使用参数解析器,重写addArgumentResolvers方法,添加自定义的解析器

> 2.自定义参数解析器,实现HandlerMethodArgumentResolver接口,重写supportsParameter和resolveArgument。

> 3.这样就可以直接在参数中增加对应的user,直接获取值了

# Jemter压力测试
> 1.官网:[http://jmeter.apache.org/](http://jmeter.apache.org/)

> 2.下载地址[http://jmeter.apache.org/download_jmeter.cgi](http://jmeter.apache.org/download_jmeter.cgi)

> 3.修改界面为中文:

        找到jmeter下的bin目录,打开jmeter.properties 文件
        第三十七行修改为
        language=zh_CN

> 3.基本步骤:

        1.添加线程组
        2.添加HTTP请求配置器:

# SpringBoot 打war包
> 1.添加依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
> 2.添加plugins

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
> 3.修改打包方式为war

    <packaging>war</packaging>

> 4.mainApplication需要继承SpringBootServletInitializer,并重写configure方法

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(MainApplication.class);
    }
> 5.项目根目录打包:mvn clean package
> 6.放tomcat目录下,启动(解决需要增加应用名)
    1.可以把context设置为空
    2.直接放到ROOT目录下

# 页面优化
一、页面缓存

   把页面渲染好的页面缓存放入redis

    实现代码:

    1.SpringBoot 2.0写法

    //取缓存
    WebContext ctx = new WebContext(request, response, request.getServletContext(), request.getLocale(), model.asMap());
    html = thymeleafViewResolver.getTemplateEngine().process("goodlist", ctx);
    if (!StringUtils.isEmpty(html)) {
        redisService.set(GoodsKey.getGoodList, "", html);
    }

    2.SpringBoot 1.0写法

    SpringWebContext context = new SpringWebContext(request,response,request.getServletContext(),request.getLocale(),model.asMap(),applicationContext);
    String html = thymeleafViewResolver.getTemplateEngine().process("goods_list",context);

二、对象缓存
> 1.在Service中,取Dao的数据时,先取redis的数据,如果redis中没有才取数据库的数据。
当数据库数据修改时,自动修改redis的数据

三、页面静态化
> 1.vue,angular进行页面静态化,减少服务器请求 

### 热部署问题:
org.springframework.boot spring-boot-devtools true

添加maven后,会自动添加热部署功能。但需要进行重新编译才可以实现更新

### 静态资源优化

1.JS/CSS压缩

2.多个CSS/JS合并,减少链接

### 集成RabbitMQ

1.安装erlong

​   1.安装依赖:

yum install ncurses-devel


​   2.下载erlang包,编译安装

​       1)http://www.erlang.org/downloads

​       2)

2.安装RabbitMQ

​   1.下载地址:http://www.rabbitmq.com/install-generic-unix.html

​   2.

## 错误记录
1.
​    (1).报错
​    
An attempt was made to call the method javax.servlet.ServletContext.getVirtualServerName()Ljava/lang/String; but it does not exist. Its class, javax.servlet.ServletContext, is available from the following locations:

jar:file:/Users/ac/.gradle/caches/modules-2/files-2.1/javax.servlet/servlet-api/2.4/3fc542fe8bb8164e8d3e840fe7403bc0518053c0/servlet-api-2.4.jar!/javax/servlet/ServletContext.class
jar:file:/Users/ac/.gradle/caches/modules-2/files-2.1/org.apache.tomcat.embed/tomcat-embed-core/8.5.34/a038040d68a90397f95dd1e11b979fe364a5000f/tomcat-embed-core-8.5.34.jar!/javax/servlet/ServletContext.class


    (2).解决:servlet-api版本太低,升级即可,
        1.下载tomcat.zip包(https://tomcat.apache.org/download-80.cgi),
        2.找到lib/servlet-api.jar,复制到java jdk目录下/jre/lib/ext下