Java高并发秒时啊API之业务分析与Dao层1

Java高并发秒时啊API之业务分析与Dao层2

---2-2---------------------------------------------------------------------------------

1 推荐从官网获取资源:1.文档更全面权威,避免过时或错误

  Spring config:  http://spring.io/docs

          http://docs.spring.io/spring/docs/4.2.9.RELEASE/spring-framework-reference/htmlsingle/

  logback config:

    manual:  https://logback.qos.ch/manual/index.html

      Chapter 3: Logback configuration:  https://logback.qos.ch/manual/configuration.html

  mybatis config: http://www.mybatis.org/mybatis-3/zh/index.html

2 maven命令创建web骨架项目

  mvn archetype:create -DgroupId=org.seckill -DartifactId=seckill -DarchetypeArtifactId=maven-archetype-webapp

  执行出错:原因([Maven] 从mvn archetype:create命令说起 http://blog.csdn.net/xiaofenglu/article/details/47614215)

  

[ERROR] Could not find goal 'create' in plugin org.apache.maven.plugins:maven-archetype-plugin:3.0.1 among available goals crawl, create-from-project, generate, help, integration-test, jar, update-local-catalog -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoNotFoundException

改为:

  mvn archetype:generate -DgroupId=org.seckill -DartifactId=seckill -DarchetypeArtifactId=maven-archetype-webapp

IDE:import project

 maven创建的web.xml中servlet版本为2.3不支持el表达式,需要改为高版本,具体内容可以从tomcat的示例文件中拷贝(从tomcat的webapps的examples/WEB-INF的web.xml参照)

  web.xml:

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
  version="3.1"
  metadata-complete="true">
  
  <!-- 修改servlet版本为3.1 -->
</web-app>

3 补全目录结构

 src/main/java

    /resources

    /webapp

      /WEB-INF

 src/test/java

    /resources

4 pom.xml

  4.1默认junit改为4.11(3.0为编程方式,4.0为annotation)

  4.2 补全项目依赖

   1.日志 java日志:slf4j,log4j,logback,common-log

    slf4j 是规范/接口

    日志实现:slf4j,log4j,logback,common-log

    使用:slf4j + logback

  <!-- 2: 数据库相关依赖 -->MySql+连接池c3p0

  <!-- DAO框架:MyBatis依赖 -->

 

注意:
    <!-- MyBatis自身实现的spring整合依赖 v1.2.3出错,替换为1.3.0 
    详细见:疑惑的 java.lang.AbstractMethodError: org.mybatis.spring.transaction.SpringManagedTransaction.getTimeout()L
    http://www.cnblogs.com/molao-doing/p/6056380.html

  -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.0</version>
    </dependency>
    错误信息:
java.lang.AbstractMethodError: org.mybatis.spring.transaction.SpringManagedTransaction.getTimeout()L错误
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.seckill</groupId>
  <artifactId>seckill</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>seckill Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <!-- 补全项目依赖-->
    <!--1:日志 java日志:slf4j,log4j,logback,common-log
    slf4j 是规范/接口
    日志实现:slf4j,log4j,logback,common-log
    使用:slf4j + logback -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.7.12</version>
    </dependency>
    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-core</artifactId>
      <version>1.1.1</version>
    </dependency>
    <!-- 实现slf4j接口并整合 -->
    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-classic</artifactId>
      <version>1.1.1</version>
    </dependency>
    <!-- 2: 数据库相关依赖 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.35</version>
      <scope>runtime</scope>
    </dependency>
    <!-- 连接池c3p0 -->
    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1.2</version>
    </dependency>
    <!-- DAO框架:MyBatis依赖 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.4</version>
    </dependency>
    <!-- MyBatis自身实现的spring整合依赖 v1.2.3出错,替换为1.3.0 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.0</version>
    </dependency>
    <!--3:Servlet web相关依赖  -->
    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.5.4</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>
    <!--4:spring依赖 -->
    <!-- 1) spring核心依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <!-- 2) spring dao层依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <!-- tx:transaction  -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <!-- 3) spring web依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
    <!-- 4) spring test相关依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>4.1.7.RELEASE</version>
    </dependency>
  </dependencies>
  <build>
    <finalName>seckill</finalName>
  </build>
</project>

===3业务分析===============================================================

---3-1 秒杀业务分析---------------------------------------------------------------------------------

商家-库存-用户

数据落地与不数据落地:
落地数据:就是被持久化的数据,这种数据一般放在硬盘或是其他的持久化存储设备里,例如:图片、系统日志、在页面上显示的数据以及保存在关系数据库里的数据等等,落地数据一定会有一个固定的载体,他们不会瞬时消失的。

不落地数据:一般指存储在内存或者是网络传输里的数据,这些数据是瞬时,使用完毕就会消失,例如:我们在浏览器发送给服务器的请求;从数据库读取出来的一直到页面展示前的数据等等。
“不落地”传输能够满足用户在性能上的要求。

事务机制:最可靠的数据落地方案(目前)
数据落地
MySQL VS NoSQL
Nosql:追求高性能、分布式。 对事务支持不好。数据落地不安全?NoSQL 所有的非关系型数据库都可以归类在这里,比如redis

---3-2 MySQL实现的难点信息---------------------------------------------------------------------------------

难点问题:竞争

MySQL:对mysql来说,秒杀这种业务的难点问题就是解决竟争。事务+行级锁

  Start Transaction

  Update 库存数量(竞争)

  Insert购买信息

  Commit

行级锁

---3-3---------------------------------------------------------------------------------

秒杀功能:

  1.秒杀接口暴露

  2.执行秒杀

  3.相关查询

代码开发阶段:

1.DAO设计编码
2.Service设计编码
3.Web设计编码

 

posted @ 2017-07-03 15:29  charles999  阅读(391)  评论(0编辑  收藏  举报