JAVA高并发秒杀API项目的学习笔记

时间:2021-09-17 12:43:17




一步一步的搭建JAVA WEB项目,采用Maven构建,基于MYBatis+Spring+Spring MVC+Bootstrap技术的秒杀项目
学习的视频:http://www.imooc.com/learn/587


创建Maven项目

  • 创建目录,执行Maven命令

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

    问题:Maven命令执行到Generating Project in Batch mode 卡住,参考链接

  • 将项目导入到IDEA工具中

  • 修改项目配置

    1. 修改web.xml中的servlet版本,默认是2.3,其不支持JSP的EL表达式。从Tomcat中的示例的web.xml中拷贝3.0的版本配置到项目中
    2. 补全目录。项目的main目录下创建java目录,在src目录下创建test目录,test目录下创建java和sources目录
    3. 打开pom.xml,进行依赖的配置

      • 单元测试依赖:Junit4
      • 日志依赖:slf4j+logback。(lf4j是规范/接口,log4j,common-logging,logback是日志的实现)
      • 数据库依赖:mysql-connector-java、c3p0
      • DAO框架:mybatis依赖:mybatis
      • Servlet web相关依赖:standard、jstl、jackson-databind、servlet-api
      • Spring依赖:spring-core、spring-beans、spring-context、spring-jdbc、spring-tx、spring-web、spring-webmvc、spring-test

        <dependencies>
        <!---3.0使用编程方式,4.0使用注解方式-->
        <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
        </dependency>

        <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接口并进行整合-->
        <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.1.1</version>
        </dependency>
        <!--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>
        <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>3.3.0</version>
        </dependency>
        <!--mybatis自身实现的spring的整合依赖-->
        <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.2.3</version>
        </dependency>
        <!--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>
        </dependency>

        <!--Spring依赖-->
        <!--spring核心-->
        <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>
        <!--spring的DAO层依赖-->
        <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.1.7.RELEASE</version>
        </dependency>
        <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>4.1.7.RELEASE</version>
        </dependency>
        <!--spring的WEB层依赖-->
        <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>
        <!--spring的单元测试依赖-->
        <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>4.1.7.RELEASE</version>
        </dependency>
        </dependencies>

        数据库的设计

        • 在项目main目录下创建sql目录,新建 schema.sql,作为数据库的创建脚本
        • 脚本代码如下:
          ```
          -- 数据库初始化脚本

        -- 创建数据库
        CREATE DATABASE seckill;

        -- 使用数据库
        use seckill;

        -- 创建秒杀库存表:使用InnoDB引擎,其支持事务。主键自增设置为从1000开始,字符格式设置为UTF8
        CREATE TABLE seckill(
        seckill_id bigint NOT NULL AUTO_INCREMENT COMMENT '商品库存id',
        name varchar(120) NOT NULL COMMENT '商品名称',
        number int NOT NULL COMMENT '库存数量',
        start_time timestamp NOT NULL COMMENT '秒杀开启时间',
        end_time timestamp NOT NULL COMMENT '秒杀结束时间',
        create_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',

        PRIMARY KEY (seckill_id),

        KEY idx_start_time(start_time),
        KEY idx_end_time(end_time),
        KEY idx_create_time(create_time)
        )ENGINE=InnoDB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8 COMMENT='秒杀库存表';

        -- 秒杀成功明细表
        CREATE TABLE success_killed(
        seckill_id bigint NOT NULL COMMENT '秒杀商品id',
        user_phone int NOT NULL COMMENT '用户手机号',
        state tinyint NOT NULL COMMENT '状态标示:-1指无效,0指成功,1指已付款',
        create_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
        PRIMARY KEY (seckill_id,user_phone),
        KEY idx_create_time(create_time)
        )ENGINE=InnoDB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8 COMMENT='秒杀成功明细表';

        -- 初始化数据
        INSERT INTO seckill(name,number,start_time,end_time)
        VALUES
        ('1000元秒杀iphone6',100,'2016-06-28 00:00:00','2016-06-29 00:00:00'),
        ('500元秒杀iphone5',200,'2016-06-28 00:00:00','2016-06-29 00:00:00'),
        ('200元秒杀小米4',300,'2016-06-28 00:00:00','2016-06-29 00:00:00'),
        ('100元秒杀红米note',400,'2016-06-28 00:00:00','2016-06-29 00:00:00');

      -- show create table seckill;
-- 为什么手写DDL,记录每次上线的DDL修改
```

DAO实体和接口

  • 创建实体包org.seckill.entity
  • 创建DAO包org.seckill.dao
  • 创建SecKill实体类,生成getter和setter,重写toString
          private long secKillId; 
    private String name;
    private int number;
    private Date startTime;
    private Date endTime;
    private Date createTime;
  • 创建SuccessKilled实体类,生成getter和setter,重写toString

          private long secKillId; 
    private long userPhone;
    private short state;
    private Date createTime;
  • 创建DAO接口SecKillDao,添加减库存,根据ID查询秒杀对象,查询秒杀商品列表方法

          /**
    * 减库存
    * @param secKillId
    * @param killTime
    * @return如果影响行数大于1,表示更新的记录行数
    */

    int reduceNumber(long secKillId,Date killTime);

    /**
    * 根据id查询秒杀对象
    * @param secKillId
    * @return
    */

    SecKill queryById(long secKillId);

    /**
    * 根据偏移量查询秒杀商品列表
    * @param offset
    * @param limit
    * @return
    */

    List<SecKill> queryAll(int offset,int limit);
  • 创建DAO接口SuccessKilledDao,添加插入购买明细,根据ID查询购买明细实体的方法

          /**
    * 插入购买明细,可过滤重复
    * @param secKillId
    * @param userPhone
    * @return插入的行数
    */

    int inertSuccessKilled(long secKillId,long userPhone);

    /**
    *根据ID查询SuccessKilled并携带秒杀产品对象实体
    * @param secKillId
    * @return
    */

    SuccessKilled queryByIdWithSecKill(long secKillId);
  • 基于MyBaits实现DAO接口

    1. 创建mybatis-config.xml全局配置文件

      <?xml version="1.0" encoding="UTF-8" ?>
      <!DOCTYPE configuration
      PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
      "http://mybatis.org/dtd/mybatis-3-config.dtd">

      <configuration>
      <!--配置全局属性-->
      <settings>
      <!--使用jdbc的getGeneratedKeys获取数据库自增主键值-->
      <setting name="useGenerateKeys" value="true"/>

      <!--使用列别名替换列名 默认为true-->
      <setting name="useColumnLabel" value="true"/>

      <!--开启驼峰命名转换-->
      <setting name="mapUnderscoreCamelCase" value="true"
      </settings>

      </configuration>
    2. 创建mapper文件夹,用于存储mybatis映射文件
    3. 创建SecKilledDao.xml映射文件

      <?xml version="1.0" encoding="UTF-8" ?>
      <!DOCTYPE mapper
      PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
      "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

      <mapper namespace="org.seckill.dao.SecKillDao">
      <!--为DAO接口方法提供sql语句配置-->
      <update id="reduceNumber">
      <!--具体的sql-->
      update
      seckill
      set
      number = number -1
      where seckill_id = #
      {secKillId}
      and start_time <![CDATA[ <= ]]> #
      {killTime}
      and end_time >= #
      {killTime}
      and number > 0;
      </update>

      <select id="queryById" resultType="SecKill" parameterType="long">
      select seckill_id,name,number,start_time,end_time,create_time
      from seckill
      where seckill_id = #
      {secKillId}
      </select>

      <select id="queryAll" resultType="SecKill">
      select seckill_id,name,number,start_time,end_time,create_time
      from seckill
      order by create_time desc
      limit #
      {offset},#{limit}
      </select>
      </mapper>
    4. 创建SuccessKilledDao.xml映射文件

      <?xml version="1.0" encoding="UTF-8" ?>
      <!DOCTYPE mapper
      PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
      "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

      <mapper namespace="org.seckill.dao.SuccessKilledDao">
      <!--为DAO接口方法提供sql语句配置-->
      <insert id="insertSuccessKilled">
      <!--ignore忽略主键冲突-->
      insert ignore into success_killed(seckill_id,user_phone)
      values (#
      {secKilled},#{userPhone})
      </insert>

      <select id="queryByIdWithSecKill" resultType="SuccessKilled">
      <!--根据id查询seccessKilled并携带seckill实体 如何告诉mybatis把结果映射到successkilled同时映射到seckill属性 mybatis可以*控制sql-->
      select
      sk.seckill_id,
      sk.user_phone,
      sk.create_time,
      sk.state,
      s.seckill_id "seckill.seckill_id",
      s.name "seckill.name",
      s.number "seckill.number",
      s.start_time "seckill.start_time",
      s.end_time "seckill.end_time",
      s.create_time "seckill.crate_time"
      from success_killed sk
      inner join seckill s on sk.seckill_id = s.seckill_id
      where sk.seckill_id = #
      {secKillId}
      </select>
      </mapper>
  • mybatis整合spring

    1. 创建spring文件,用于存储spring配置文件
    2. 创建spring-dao.xml配置文件
    3. 创建jdbc.properties配置文件,用于存储数据库相关信息
       driver=com.mysql.jdbc.Driver
      url=jdbc:mysql://127.0.0.1:3306/seckill?useUnicode=true&characterEncoding=utf-8
      username=root
      password=purple
    4. 在spring-dao.xml配置文件中进行四个步骤的配置

      • 配置数据库相关参数
      • 配置数据库连接池
      • 配置sqlSessionFactory对象
      • 配置扫描dao接口包,动态实现 dao接口,并注入到spring容器中
       <?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"
      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-3.1.xsd"
      >

      <!--配置整合mybatis过程-->
      <!--配置数据库相关参数-->
      <context:property-placeholder location="classpath:jdbc.properties"/>

      <!--数据库连接池-->
      <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
      <property name="driverClass" value="${driver" />
      <property name="jdbcUrl" value="${url}"/>
      <property name="user" value="${username}"/>
      <property name="password" value="${password}"/>

      <property name="maxPoolSize" value="30"/>
      <property name="minPoolSize" value="10"/>
      <!--关闭连接后不自动commit-->
      <property name="autoCommitOnClose" value="false"/>
      <!--获取连接超时的时间-->
      <property name="checkoutTimeout" value="1000"/>
      <!--获取连接失败的重试次数-->
      <property name="acquireRetryAttempts" value="2"/>
      </bean>

      <!--配置sqlSessionFactory对象-->
      <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
      <!--注入数据库连接池-->
      <property name="dataSource" value="dataSource"/>
      <!--配置mybatis全局配置文件-->
      <property name="configLocation" value="classpath:mybatis-config.xml"/>
      <!--扫描entity包,使用别名-->
      <property name="typeAliasesPackage" value="org.seckill.entity"/>
      <!--扫描sql配置文件-->
      <property name="mapperLocations" value="mapper/*.xml"/>
      </bean>

      <!--配置扫描dao接口包,动态实现 dao接口,并注入到spring容器中-->
      <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
      <!--注入sqlSessionFactory对象-->
      <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
      <!--给出扫描Dao接口包-->
      <property name="basePackage" value="org.seckill.dao"/>
      </bean>
      </beans>
  • Junit4与Spring进行整合,进行Junit4单元测试

    1. 创建SecKillDao的单元测试类

      @RunWith(SpringJUnit4ClassRunner.class)
      @ContextConfiguration("classpath:spring/spring-dao.xml")
      public class SecKillDaoTest {
      //注入DAO实现类依赖
      @Resource
      private SecKillDao secKillDao;

      @Test
      public void testReduceNumber() throws Exception {
      Date killTime = new Date();
      int result = secKillDao.reduceNumber(1000L,killTime);
      System.out.println(result);

      }

      @Test
      public void testQueryById() throws Exception {
      long id = 1000;
      SecKill secKill = secKillDao.queryById(id);
      System.out.println(secKill.getName());
      }

      @Test
      public void testQueryAll() throws Exception {
      List<SecKill> secKillList = secKillDao.queryAll(0,1000);

      for(SecKill row : secKillList){
      System.out.println(row.toString());
      }
      }
      }
    2. 创建SuccessKilledDao的单元测试类

      @RunWith(SpringJUnit4ClassRunner.class)
      @ContextConfiguration("classpath:spring/spring-dao.xml")
      public class SuccessKilledDaoTest {
      @Resource
      private SuccessKilledDao successKilledDao;

      @Test
      public void testInertSuccessKilled() throws Exception {
      int result = successKilledDao.insertSuccessKilled(1000L,28059830451L);
      System.out.println(result);

      }

      @Test
      public void testQueryByIdWithSecKill() throws Exception {
      SuccessKilled successKilled = successKilledDao.queryByIdWithSecKill(1000L,2147483647L);
      System.out.println(successKilled.toString());
      }
      }
    3. 学习点
      • 单元测试类可以利用IDEA的快捷键,直接在要测试的类中进行代码的生成
      • mybatis的传参,需要在DAO接口方法的形参中使用@Param注解进行指明

业务层设计

  • 秒杀业务接口设计

    1. 创建业务包service
    2. 创建数据传输实体包dto
    3. 创建异常包exception
    4. 创建dto实体

      • 创建暴露秒杀地址DTO:Exposer

        public class Exposer {
        /**
        * 是否开启秒杀
        */

        private boolean exposed;

        /**
        * 秒杀ID
        */

        private long secKillId;

        /**
        * 一种加密措施
        */

        private String md5;

        /**
        *系统当前时间(毫秒值)
        */

        private long now;

        private long start;

        private long end;

        public Exposer(boolean exposed, String md5, long secKillId) {
        this.exposed = exposed;
        this.md5 = md5;
        this.secKillId = secKillId;
        }

        public Exposer(boolean exposed, long now, long start, long end) {
        this.exposed = exposed;
        this.now = now;
        this.start = start;
        this.end = end;
        }

        public Exposer(boolean exposed, long secKillId) {
        this.exposed = exposed;
        this.secKillId = secKillId;
        }

        public boolean isExposed() {
        return exposed;
        }

        public void setExposed(boolean exposed) {
        this.exposed = exposed;
        }

        public long getSecKillId() {
        return secKillId;
        }

        public void setSecKillId(long secKillId) {
        this.secKillId = secKillId;
        this.secKillId = secKillId;
        }

        public String getMd5() {
        return md5;
        }

        public void setMd5(String md5) {
        this.md5 = md5;
        }

        public long getNow() {
        return now;
        }

        public void setNow(long now) {
        this.now = now;
        }

        public long getStart() {
        return start;
        }

        public void setStart(long start) {
        this.start = start;
        }

        public long getEnd() {
        return end;
        }

        public void setEnd(long end) {
        this.end = end;
        }
        }
      • 创建封装秒杀执行后结果DTO:SecKillExecution

        public class SecKillExecution {

        private long secKillId;

        /**
        * 秒杀执行结果状态
        */
        private int state;

        /**
        * 状态表示
        */
        private String stateInfo;

        private SuccessKilled successKilled;

        public SecKillExecution(long secKillId, int state, String stateInfo, SuccessKilled successKilled) {
        this.secKillId = secKillId;
        this.state = state;
        this.stateInfo = stateInfo;
        this.successKilled = successKilled;
        }

        public SecKillExecution(long secKillId, int state, String stateInfo) {
        this.secKillId = secKillId;
        this.state = state;
        this.stateInfo = stateInfo;
        }

        public long getSecKillId() {
        return secKillId;
        }

        public void setSecKillId(long secKillId) {
        this.secKillId = secKillId;
        }

        public int getState() {
        return state;
        }

        public void setState(int state) {
        this.state = state;
        }

        public String getStateInfo() {
        return stateInfo;
        }

        public void setStateInfo(String stateInfo) {
        this.stateInfo = stateInfo;
        }

        public SuccessKilled getSuccessKilled() {
        return successKilled;
        }

        public void setSuccessKilled(SuccessKilled successKilled) {
        this.successKilled = successKilled;
        }
        }
    5. 创建异常类

      • 创建业务相关异常:SecKillException

        public class SecKillException extends RuntimeException{
        public SecKillException(String message) {
        super(message);
        }

        public SecKillException(String message, Throwable cause) {
        super(message, cause);
        }
        }
      • 创建重复秒杀异常类:RepeatKillException

        public class RepeatKillException extends SecKillException{
        public RepeatKillException(String message, Throwable cause) {
        super(message, cause);
        }

        public RepeatKillException(String message) {
        super(message);
        }
        }
      • 创建秒杀关闭异常类:SecKillCloseExce
        ption

        public class SecKillCloseException extends SecKillException{
        public SecKillCloseException(String message) {
        super(message);
        }

        public SecKillCloseException(String message, Throwable cause) {
        super(message, cause);
        }
        }
    6. 创建SecKillService业务接口:SecKillService

      • 创建查询所有的秒杀记录方法:getSecKillList
      • 创建查询单个秒杀记录方法:getById
      • 创建秒杀开启时输出秒杀接口地址方法:exportSecKillUrl
      • 创建执行秒杀操作方法:executeSecKill

        public interface SecKillService {
        /**
        * 查询所有的秒杀记录
        * @return
        */

        List<SecKill> getSecKillList();

        /**
        * 查询单个秒杀记录
        * @param secKillId
        * @return
        */

        SecKill getById(long secKillId);

        /**
        * 秒杀开启时输出秒杀接口地址
        * 否则输出系统时间和秒杀时间
        * 防止用户猜测出秒杀地址的规律
        * @param secKillId
        */

        Exposer exportSecKillUrl(long secKillId);

        /**
        *执行秒杀操作
        * @param secKillId
        * @param userPhone
        * @param md5
        */

        SecKillExecution executeSecKill(long secKillId,long userPhone,String md5) throws SecKillException,RepeatKillException,SecKillCloseException;
        }
    7. 业务接口设计的学习点

      • 站在使用者的角度进行设计接口,不要冗余设计
      • 方法定义粒度,目的明确。非常友好的让使用者调用接口
      • 参数要简炼
      • 返回类型要清晰
  • 秒杀业务接口实现

    1. 新建enums枚举包,将数据字典放到枚举中
    2. 在枚举包下创建秒杀状态枚举:SecKillStatEnum

      public enum SecKillStatEnum {
      SUCCESS(1,"秒杀成功"),
      END(0,"秒杀结束"),
      REPEAT(-1,"重复秒杀"),
      INNER_ERROR(-2,"系统异常"),
      DATA_REWRITE(-3,"数据篡改");

      private int state;
      private String stateInfo;

      SecKillStatEnum(int state, String stateInfo) {
      this.state = state;
      this.stateInfo = stateInfo;
      }

      public int getState() {
      return state;
      }

      public String getStateInfo() {
      return stateInfo;
      }

      public static SecKillStatEnum stateOf(int index){
      for(SecKillStatEnum state : values()) {
      if(state.getState() == index){
      return state;
      }
      }

      return null;

      }
      }
    3. 在service包下新建impl包
    4. 创建SecKillServiceImpl实现类,实现SecKillService接口方法

      public class SecKillServiceImpl implements SecKillService{
      private Logger logger = LoggerFactory.getLogger(SecKillService.class);

      private SecKillDao secKillDao;
      private SuccessKilledDao successKilledDao;

      //混淆字符,用于混淆MD5
      private final String salt = "sdlkjs#$#$dfowierlkjafdmv232k3j@@##$";

      @Override
      public List<SecKill> getSecKillList() {
      return secKillDao.queryAll(0,4);
      }

      @Override
      public SecKill getById(long secKillId) {
      return secKillDao.queryById(secKillId);
      }

      @Override
      public Exposer exportSecKillUrl(long secKillId) {
      SecKill secKill = secKillDao.queryById(secKillId);

      if(null == secKill){
      return new Exposer(false,secKillId);
      }

      Date startTime = secKill.getStartTime();
      Date endTime = secKill.getEndTime();
      Date nowTime = new Date();

      if(nowTime.getTime() < startTime.getTime()
      || nowTime.getTime() > endTime.getTime()){
      return new Exposer(false,secKillId,nowTime.getTime(),startTime.getTime(),endTime.getTime());
      }

      //转化特定字符串的过程,不可逆
      String md5 = getMD5(secKillId);

      return new Exposer(true,md5,secKillId);

      }

      @Override
      public SecKillExecution executeSecKill(long secKillId, long userPhone, String md5)
      throws SecKillException, RepeatKillException, SecKillCloseException
      {
      if(null == md5 || md5.equals(getMD5(secKillId))){
      throw new SecKillException("seckill datarewirte");
      }

      try{
      //执行秒杀逻辑,减库存,记录购买行为
      Date nowTime = new Date();
      //减库存
      int updateCount = secKillDao.reduceNumber(secKillId,nowTime);

      if(updateCount <= 0){
      //没有更新到记录,秒杀结束
      throw new SecKillCloseException("seckill is Closed");
      }else{
      //记录购买行为
      int insertCount = successKilledDao.insertSuccessKilled(secKillId,userPhone);

      //唯一:secKillId,userPhone
      if(insertCount <= 0){
      //重复秒杀
      throw new RepeatKillException("seckill repeated");
      }else{
      //秒杀成功
      SuccessKilled successKilled = successKilledDao.queryByIdWithSecKill(secKillId,userPhone);

      return new SecKillExecution(secKillId, SecKillStatEnum.SUCCESS,successKilled);
      }
      }
      }catch(SecKillCloseException e1){
      throw e1;
      }catch(RepeatKillException e2){
      throw e2;
      }catch (Exception e){
      logger.error(e.getMessage(),e);
      //所有编译期异常,转化为运行期异常
      throw new SecKillException("seckill inner error:" + e.getMessage());
      }
      }

      /**
      * 生成MD5
      * @param secKillId
      * @return
      */

      private String getMD5(long secKillId){
      String base = secKillId + "/" + salt;
      String md5 = DigestUtils.md5DigestAsHex(base.getBytes());
      return md5;
      }
      }
  • 基于Spring托管Service实现类

    1. 创建Spring的service配置spring-service.xml,进行service包下的注解类型的扫描配置

      <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"
      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-3.1.xsd"
      >

      <!--扫描service包下所有注解的类型-->
      <context:component-scan base-package="org.seckill.service"/>

      </beans>
    2. 在service实现类中添加上@Service的注解,在类中的dao对象添加上@Autowired的注解
  • 配置并使用Spring声明式事务

    1. 在spring-service.xml中添加上配置事务管理器
      <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <!--注入数据库连接池-->
      <property name="dataSource" ref="dataSource"/>
      </bean>
    2. 在spring-service.xml中添加上配置基于注解的声明式事务
      <tx:annotation-driven transaction-manager="transactionManager"/>
    3. 在业务类的executeSecKill方法中添加上@Transactional事务注解
    4. 学习点:使用注解控制事务方法的优点
      • 开发团队达到一致约定,明确标注事务方法的编程风格
      • 保证事务方法的执行时间尽可能短,不要穿插其他网络操作RPC/HTTP请求,或者剥离到事务方法外部
      • 不是所有的方法都需要事务,如只有一条修改操作,只读操作就不需要事务控制
  • Service集成测试

    1. 添加上logback的日志配置文件logback.xml

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

      <configuration debug="true">
      <!-- ch.qos.logback.core.ConsoleAppender 控制台输出 -->
      <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
      <encoder>
      <pattern>[%-5level] %d
      {HH:mm:ss.SSS} [%thread] %logger{36} - %msg%n</pattern>
      </encoder>

      </appender>

      <!-- 日志级别 -->
      <root>
      <level value="debug" />
      <appender-ref ref="STDOUT" />
      </root>

      </configuration>
    2. 使用IDEA为SecKillService业务接口创建单元测试类SecKillServiceTest
    3. 编写单元测试方法

      @RunWith(SpringJUnit4ClassRunner.class)
      @ContextConfiguration({"classpath:spring/spring-dao.xml","classpath:spring/spring-service.xml"})
      public class SecKillServiceTest {
      private final Logger logger = LoggerFactory.getLogger(this.getClass());
      @Autowired
      private SecKillService secKillService;
      @Test
      public void testGetSecKillList() throws Exception {
      List<SecKill> list = secKillService.getSecKillList();
      logger.info("list={}",list);
      }

      @Test
      public void testGetById() throws Exception {
      SecKill secKill = secKillService.getById(1000L);
      logger.info("secKill:{}",secKill);

      }

      /**
      * 测试完整业务,注意集成测试代码完整逻辑,注意可重复执行
      * @throws Exception
      */

      @Test
      public void testSecKillLogic() throws Exception {
      long id = 1000L;
      Exposer exposer = secKillService.exportSecKillUrl(id);

      if(exposer.isExposed()){
      logger.info("exposer={}",exposer);
      long phone = 18059830432L;
      SecKillExecution secKillExecution = secKillService.executeSecKill(id,phone,exposer.getMd5());
      logger.info("secKillExecution:{}",secKillExecution);
      }else{
      //秒杀未开始
      logger.warn("exposer={}",exposer);
      }
      }

      @Test
      public void testExportSecKillUrl() throws Exception {
      long id = 1000L;
      Exposer exposer = secKillService.exportSecKillUrl(id);
      logger.info("exposer={}",exposer);

      }

      @Test
      public void testExecuteSecKill() throws Exception {
      long id = 1000L;
      long phone = 18059830452L;
      String md5 = "f1974250b060f51c4a8e48df67232d53";

      SecKillExecution secKillExecution = secKillService.executeSecKill(id,phone,md5);

      logger.info("secKillExecution:{}",secKillExecution);

      }
      }
    4. 单元测试的学习点
      • 集成测试的业务逻辑的完整性
      • 注意测试的可重复执行

WEB层设计

  • 设计Restful接口

  • SpringMVC整合Spring

    1. 在web.xml中配置DispatcherServlet
    2. 创建web包
    3. 创建spring-web.xml配置文件
    4. 在spring-web.xml进行SpringMVC的配置

      • 开启SpringMVC注解模式
      • servlet-mapping映射路径
      • 配置jsp显示viewResolver
      • 扫描web相关的bean

        <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:conext="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"
        >

        <!--配置Spring MVC-->
        <!--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,数字和日期的转化@NumberFormat,@DataTimeFormat
        xml,json默认读写支持
        -->

        <mvc:annotation-driven/>

        <!--servlet-mapping映射路径-->
        <!--静态资源默认servlet配置
        1、加入对静态资源的处理:js,css,img
        2、允许使用/做整体映射
        -->

        <mvc:default-servlet-handler/>

        <!--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>

        <!--扫描web相关的bean-->
        <conext:component-scan base-package="org.seckill.web"/>

        </beans>
  • 实现秒杀相关的Restful接口

    1. 创建控制类SecKillController,实现获取列表,获取单条数据,获取系统时间,获取秒杀地址,秒杀的方法

      @Controller
      @RequestMapping("/seckill/")//模块/资源
      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){
      List<SecKill> list = secKillService.getSecKillList();
      model.addAttribute("list",list);
      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 "redirect:/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("secKillId") Long secKillId){
      SecKillResult<Exposer> result = null;

      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"})

      public SecKillResult<SecKillExecution> excute(@PathVariable("secKillId") Long secKillId,
      @PathVariable("md5") String md5,
      @CookieValue(value="killPhone",required = false) Long userPhone){
      //springmvc valid
      if(userPhone == null){
      return new SecKillResult<SecKillExecution>(false,"未注册");
      }

      SecKillResult<SecKillExecution> result = null;

      try{
      SecKillExecution secKillExecution = secKillService.executeSecKill(secKillId,userPhone,md5);
      result = new SecKillResult<SecKillExecution>(true,secKillExecution);

      }catch(RepeatKillException e){
      SecKillExecution secKillExecution = new SecKillExecution(secKillId, SecKillStatEnum.REPEAT);
      result = new SecKillResult<SecKillExecution>(false,secKillExecution);

      }catch(SecKillCloseException e){
      SecKillExecution secKillExecution = new SecKillExecution(secKillId, SecKillStatEnum.END);
      result = new SecKillResult<SecKillExecution>(false,secKillExecution);

      }catch(Exception e){
      logger.error(e.getMessage(),e);
      SecKillExecution secKillExecution = new SecKillExecution(secKillId, SecKillStatEnum.INNER_ERROR);
      result = new SecKillResult<SecKillExecution>(false,secKillExecution);
      }

      return result;
      }

      @RequestMapping(value="/time/now",method=RequestMethod.GET)
      public SecKillResult<Long> time(){
      Date now = new Date();
      return new SecKillResult<Long>(true,now.getTime());

      }
      }
  • 基于Bootstrap开发页面结构

    1. 创建jsp文件夹,创建common/header.jsp,common/tag.jsp,list.jsp,detail.jsp,并引入bootstrap框架,jquery、cookie、countdown插件,可以从百度和bootcss的CDN中引入插件。

    2. 创建js文件seckill.js,进行登录、计时的交互逻辑的编码,并在详细页面中引入
      ```
      var seckill = {
      //封装秒杀相关ajax的url
      URL: {

      now: function(){
      return '/seckill/time/now';
      },
      exposer: function(id){
      return '/seckill/' + id + '/exposer';
      },
      execution : function(id,md5){
      return '/seckill/' + id + '/' + md5 + '/execution';
      }

      },
      //处理秒杀逻辑
      handleSecKillKill: function(secKillId,node){

        node.hide().html('<button class="btn btn-primary btn-lg" id="killBtn">开始秒杀</button>');

      $.post(seckill.URL.exposer(secKillId),{},function(result){
      if(result && result.success){
      var exposer = result.data;

      if(exposer.exposed){
      //开启秒杀
      //获取秒杀地址
      var killUrl = seckill.URL.execution(secKillId,exposer.md5);
      console.log('killUrl:',killUrl);
      //绑定一次点击事件
      $('#killBtn').one('click',function(){
      //执行秒杀请求
      $(this).addClass('disabled');
      $.post(killUrl,{},function(result){
      if(result && result.success){
      var killResult = result.data;
      var state = killResult.state;
      var stateInfo = killResult.stateInfo;

      node.html('<span class="label label-success">'+stateInfo+'</span>');
      }
      });
      });

      node.show();
      }else{
      //未开启秒杀
      //重新计算计时逻辑
      seckill.countdown(secKillId,exposer.now,exposer.start,exposer.end);
      }

      }else{
      console.error('result:',result);
      }
      });

      },
      //计时
      countdown: function(secKillId,nowTime,startTime,endTime){

        var $secKillBox = $('#seckill-box');

      if(nowTime > endTime){
      $secKillBox.html('秒杀结束');
      }else if(nowTime < startTime){
      $secKillBox.html('秒杀未开始');
      var killTime = new Date(startTime + 1000);

      $secKillBox.countdown(killTime,function(event){
      var format = event.strftime('秒杀倒计时:%D天 %H时 %M分 %S秒');
      $secKillBox.html(format);
      }).on('finish.countdown',function(){
      //获取秒杀地址,控制实现逻辑,执行秒杀
      seckill.handleSecKillKill(secKillId,$secKillBox);
      });
      }else{
      //秒杀开始
      seckill.handleSecKillKill(secKillId,$secKillBox);
      }
     },
//验证手机号
validatePhone: function(phone){
if(phone && phone.length == 11 && !isNaN(phone)){
return true;
}else{
return false;
}
},
//详情页秒杀逻辑
detail: {
//详情页初始化
init: function(params){
//用户手机验证和登录,计时交互
//规划交互流程
//在cookie中查找手机号
var killPhone = $.cookie('killPhone'),
startTime = params.startTime,
endTime = params.endTime,
secKillId = params.secKillId;

//验证手机号
if(!seckill.validatePhone(killPhone)){
var killPhoneModal = $('#killPhoneModal');

killPhoneModal.modal({
show: true,
backdrop: 'static',//禁止位置关闭
keyboard: false//关闭键盘事件
});

$('#killPhoneBtn').click(function(){
var inputPhone = $('#killPhoneKey').val();
if(seckill.validatePhone(inputPhone)){
//电话写入cookie
$.cookie('killPhone',inputPhone,{expires:7,path: '/seckill'})
window.location.reload();

}else{
//正常下会有一个前端字典
$('#killPhoneMessage').hide().html('<label class="label label-danger">手机号码错误</label>').show(300);
}
});
}

//用户已经登录
//计时交互
$.get(seckill.URL.now(),function(result){
if(result && result.success){
var nowTime = result.data;
seckill.countdown(secKillId,nowTime,startTime,endTime);

}else{
consolw.error('result:',result);
}
});
}

}

}
```
3. 在detail.jsp页面中引入seckill.js文件,并进行初始化
`
``
<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},
endTime: ${secKill.endTime.time}
});
});
</script>
```