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;//idprivate 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;}@Overridepublic 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;}@Overridepublic 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());@Autowiredprivate SeckillDao seckillDao;@Autowiredprivate SuccessKilledDao successKilledDao;//MD5盐值字符串，用于混淆MD5private 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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://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());@Autowiredprivate SeckillService seckillService;@Testpublic void getSeckillList() {List<Seckill> list=seckillService.getSeckillList();logger.info("list={}",list);}@Testpublic 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@Testpublic 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);}}
}