JAVA高并发秒杀API项目的学习笔记

作者: 叶子的翅膀 | 来源:发表于2016-07-03 23:46 被阅读10073次

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

 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

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
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
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

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>

创建mapper文件夹，用于存储mybatis映射文件
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>

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可以自由控制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

创建spring文件，用于存储spring配置文件
创建spring-dao.xml配置文件
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
```

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

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());
        }
    }
}

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());
    }
}

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

创建业务包service
创建数据传输实体包dto
创建异常包exception

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;
    }
}

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);
    }
}

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;
 }

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

新建enums枚举包，将数据字典放到枚举中
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;

    }
}

在service包下新建impl包
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

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>

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">
    
     <property name="dataSource" ref="dataSource"/>
</bean>
```
1. 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"/> 
```
1. 在业务类的executeSecKill方法中添加上@Transactional事务注解
2. 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

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>

使用IDEA为SecKillService业务接口创建单元测试类SecKillServiceTest
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);

    }
}

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

在web.xml中配置DispatcherServlet
创建web包
创建spring-web.xml配置文件

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

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

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。
- 链接：http://www.bootcdn.cn/
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);
                 }
             });
         }

     }

 }

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>

JAVA高并发秒杀API项目的学习笔记

创建Maven项目

数据库的设计

DAO实体和接口

业务层设计

WEB层设计

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