java高并发秒杀项目之Service层

2022-07-15 13:40:09

Java高并发秒杀系统Service

具体可以参考github

service接口设计

在org.seckill包下创建一个service包用于存放我们的Service接口和其实现类，创建一个exception包用于存放service层出现的异常例如重复秒杀商品异常、秒杀已关闭等异常，一个dto包作为传输层,dto和entity的区别在于:entity用于业务数据的封装，而dto用于完成web和service层的数据传递。

package org.seckill.service;

import org.seckill.dto.Exposer;
import org.seckill.dto.SeckillExecution;
import org.seckill.entity.Seckill;
import org.seckill.exception.RepeatKillException;
import org.seckill.exception.SeckillCloseException;
import org.seckill.exception.SeckillException;

import java.util.List;

public interface SeckillService {
    /**
     * 查询全部的秒杀记录
     * @return
     */
    List<Seckill> getSeckillList();

    /**
     *查询单个秒杀记录
     * @param seckillId
     * @return
     */
    Seckill getById(long seckillId);


    //再往下，是我们最重要的行为的一些接口

    /**
     * 在秒杀开启时输出秒杀接口的地址，否则输出系统时间和秒杀时间
     * @param seckillId
     */
    Exposer exportSeckillUrl(long seckillId);


    /**
     * 执行秒杀操作，有可能失败，有可能成功，所以要抛出我们允许的异常
     * @param seckillId
     * @param userPhone
     * @param md5
     * @return
     */
    SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
            throws SeckillException,RepeatKillException,SeckillCloseException;
}

相应在的dto包中创建Exposer.java，用于封装秒杀的地址信息，各个属性的作用在代码中已给出注释，代码如下:

package org.seckill.dto;

public class Exposer {
    //是否开启秒杀
    private boolean exposed;
    //MD5加密措施
    private String md5;
    //id
    private long seckillId;
    //系统当前时间（毫秒）
    private long now;
    //开启时间
    private long start;
    //关闭时间
    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 seckillId, long now, long start, long end) {
        this.exposed = exposed;
        this.seckillId=seckillId;
        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 String getMd5() {
        return md5;
    }

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

    public long getSeckillId() {
        return seckillId;
    }

    public void setSeckillId(long seckillId) {
        this.seckillId = seckillId;
    }

    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;
    }

    @Override
    public String toString() {
        return "Exposer{" +
                "exposed=" + exposed +
                ", md5='" + md5 + '\'' +
                ", seckillId=" + seckillId +
                ", now=" + now +
                ", start=" + start +
                ", end=" + end +
                '}';
    }
}

和SeckillExecution.java，用于判断秒杀是否成功，成功就返回秒杀成功的所有信息(包括秒杀的商品id、秒杀成功状态、成功信息、用户明细)，失败就抛出一个我们允许的异常(重复秒杀异常、秒杀结束异常),代码如下:

package org.seckill.dto;

import org.seckill.entity.SuccessKilled;
import org.seckill.enums.SeckillStatEnum;

public class SeckillExecution {
    private long seckillId;

    //秒杀执行结果状态
    private int state;

    //状态表示
    private String stateInfo;

    //秒杀成功对象
    private SuccessKilled successKilled;

    public SeckillExecution(long seckillId, SeckillStatEnum seckillStatEnum, SuccessKilled successKilled) {
        this.seckillId = seckillId;
        this.state = seckillStatEnum.getState();
        this.stateInfo = seckillStatEnum.getStateInfo();
        this.successKilled = successKilled;
    }

    public SeckillExecution(long seckillId, SeckillStatEnum seckillStatEnum) {
        this.seckillId = seckillId;
        this.state = seckillStatEnum.getState();
        this.stateInfo = seckillStatEnum.getStateInfo();
    }

    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;
    }

    @Override
    public String toString() {
        return "SeckillExecution{" +
                "seckillId=" + seckillId +
                ", state=" + state +
                ", stateInfo='" + stateInfo + '\'' +
                ", successKilled=" + successKilled +
                '}';
    }
}

然后需要创建我们在秒杀业务过程中允许的异常，重复秒杀异常RepeatKillException.java:

package org.seckill.exception;

import org.seckill.entity.Seckill;

/**
 * 重复秒杀异常，是一个运行期异常，不需要我们手动try catch
 * Mysql只支持运行期异常的回滚操作
 */
public class RepeatKillException extends SeckillException{
    public RepeatKillException(String message) {
        super(message);
    }

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

秒杀关闭异常SeckillCloseException.java:

package org.seckill.exception;

import org.seckill.entity.Seckill;

//秒杀关闭异常
public class SeckillCloseException extends SeckillException{
    public SeckillCloseException(String message) {
        super(message);
    }

    public SeckillCloseException(String message, Throwable cause) {
        super(message, cause);
    }
}

和一个异常包含与秒杀业务所有出现的异常SeckillException.java:

package org.seckill.exception;

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

    public SeckillException(String message, Throwable cause) {
        super(message, cause);
    }
}

秒杀Service接口的实现

在service包下创建Impl包存放它的实现类，SeckillServiceImpl.java，内容如下:

package org.seckill.service.Impl;

import org.seckill.dao.SeckillDao;
import org.seckill.dao.SuccessKilledDao;
import org.seckill.dto.Exposer;
import org.seckill.dto.SeckillExecution;
import org.seckill.entity.Seckill;
import org.seckill.entity.SuccessKilled;
import org.seckill.enums.SeckillStatEnum;
import org.seckill.exception.RepeatKillException;
import org.seckill.exception.SeckillCloseException;
import org.seckill.exception.SeckillException;
import org.seckill.service.SeckillService;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import java.security.DigestException;
import java.util.Date;
import java.util.List;
//@Component @Service @Dao @Controller
@Service
public class SeckillServiceImpl implements SeckillService{
    private org.slf4j.Logger logger= LoggerFactory.getLogger(this.getClass());
    @Autowired
    private SeckillDao seckillDao;
    @Autowired
    private SuccessKilledDao successKilledDao;

    //MD5盐值字符串，用于混淆MD5
    private final String slat="dsnvs&&(&(*ndkasj23dbkasbdkj43sabdka543bdkab%^%$%$%";
    public List<Seckill> getSeckillList() {
        return seckillDao.queryAll(0,4);
    }

    public Seckill getById(long seckillId) {
        return seckillDao.queryById(seckillId);
    }

    public Exposer exportSeckillUrl(long seckillId) {
        Seckill seckill=seckillDao.queryById(seckillId);
        if(seckill==null){
            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);
    }

    private String getMD5(long seckillId){
        String base=seckillId+"/"+slat;
        String md5= DigestUtils.md5DigestAsHex(base.getBytes());
        return md5;
    }
    @Transactional
    /**
     * 使用注解控制事务方法的优点:
     * 1.开发团队达成一致约定，明确标注事务方法的编程风格
     * 2.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
     * 3.不是所有的方法都需要事务，如只有一条修改操作、只读操作不要事务控制
     */
    public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5) throws SeckillException, RepeatKillException, SeckillCloseException {
        if(md5==null||!md5.equals(getMD5(seckillId))){
            throw new SeckillException("seckill data rewrite");
        }
        //执行业务逻辑
        Date nowTime=new Date();
        try {
            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);
                if (insertCount <= 0) {
                    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());
        }
    }
}

然后在org.seckill包下新建一个枚举包enums，创建一个枚举类型SeckillStatEnum.java，内容如下:

package org.seckill.enums;

public enum SeckillStatEnum {
    SUCCESS(1,"秒杀成功"),
    END(0,"秒杀结束"),
    REPEAT_KILL(-1,"重复秒杀"),
    INNER_ERROR(-2,"系统异常"),
    DATE_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;
    }
}

使用spring管理service

在spring包下创建一个spring-service.xml文件，内容如下:

<?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.xsd">

    <!--扫描service包下所有使用注解的类型-->
    <context:component-scan base-package="cn.codingxiaxw.service"/>
    
</beans>

然后采用注解的方式将Service的实现类加入到Spring IOC容器中:

//@Component @Service @Dao @Controller
@Service
public class SeckillServiceImpl implements SeckillService

使用spring声明式事务配置

声明式事务的使用方式:1.早期使用的方式:ProxyFactoryBean+XMl.2.tx:advice+aop命名空间，这种配置的好处就是一次配置永久生效。3.注解@Transactional的方式。在实际开发中，建议使用第三种对我们的事务进行控制，优点见下面代码中的注释。下面让我们来配置声明式事务，在spring-service.xml中添加对事务的配置:

<!--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>

  <!--配置基于注解的声明式事务
  默认使用注解来管理事务行为-->
  <tx:annotation-driven transaction-manager="transactionManager"/>

然后在Service实现类的方法中，在需要进行事务声明的方法上加上事务的注解:

//秒杀是否成功，成功:减库存，增加明细；失败:抛出异常，事务回滚
   @Transactional
   /**
    * 使用注解控制事务方法的优点:
    * 1.开发团队达成一致约定，明确标注事务方法的编程风格
    * 2.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
    * 3.不是所有的方法都需要事务，如只有一条修改操作、只读操作不要事务控制
    */
   public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
           throws SeckillException, RepeatKillException, SeckillCloseException {}

使用集成测试Service逻辑

在SeckillService接口中使用IDEA快捷键shift+command+T，快速生成junit测试类。Service实现类中前面两个方法很好实现，获取列表或者列表中的一个商品的信息即可，测试如下:

package org.seckill.service;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.seckill.dto.Exposer;
import org.seckill.dto.SeckillExecution;
import org.seckill.entity.Seckill;
import org.seckill.exception.RepeatKillException;
import org.seckill.exception.SeckillCloseException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring/spring-*.xml")
public class SeckillServiceTest {
    private final Logger logger= LoggerFactory.getLogger(this.getClass());
    @Autowired
    private SeckillService seckillService;
    @Test
    public void getSeckillList() {
        List<Seckill> list=seckillService.getSeckillList();
        logger.info("list={}",list);
    }

    @Test
    public void getById() {
        long seckillId=1000;
        Seckill seckill=seckillService.getById(seckillId);
        logger.info("seckill={}",seckill);
    }
    //完整逻辑代码测试，注意可重复执行
    @Test
    public void testSeckillLogic() {
        long seckillId=1000;
        Exposer exposer=seckillService.exportSeckillUrl(seckillId);
        if(exposer.isExposed()){
            logger.info("exposer={}"+exposer);
            long userPhone=13476191896L;
            String md5=exposer.getMd5();
            try{
                SeckillExecution seckillExecution=seckillService.executeSeckill(seckillId,userPhone,md5);
                logger.info("result={}",seckillExecution);
            }catch (RepeatKillException e){
                logger.error(e.getMessage());
            }catch (SeckillCloseException e1){
                logger.error(e1.getMessage());
            }
        }else{
            //秒杀未开启
            logger.warn("exposer={}",exposer);
        }
    }
}

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