上篇文章介紹了秒殺的dao 這邊將介紹秒殺的業(yè)務(wù)邏輯代碼扇商。主要有統(tǒng)一異常的控制毒姨，統(tǒng)一的枚舉表示秒殺的狀態(tài)，秒殺的業(yè)務(wù)邏輯溶浴，通用返回乍迄。
首先定義一個枚舉，表示秒殺的狀態(tài)

一.枚舉定義

public enum SeckillStatEnum {
    SUCCESS(1,"秒殺成功"),
    END(0,"秒殺結(jié)束"),
    REPEAT_KILL(-1,"重復(fù)秒殺"),
    INNER_KILL(-2,"系統(tǒng)異常"),
    DATA_REWRITE(-3,"數(shù)據(jù)篡改"),
    ;
    
    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;
    }
    private int state;
    private String  stateInfo;
    private SeckillStatEnum(int state, String stateInfo) {
        this.state = state;
        this.stateInfo = stateInfo;
    }
    public static SeckillStatEnum stateInfo(int index) {
        for(SeckillStatEnum state :values()) {
            if(state.getState()==index) {
                return state;
            }
        }
        return null;
    }
}

接下來設(shè)置三個異常 主要是重復(fù)秒殺異常士败，秒殺結(jié)束異常闯两，以及秒殺異常。
二.異常定義
1.秒殺異常

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

2.重復(fù)秒殺異常

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

3.秒殺結(jié)束異常

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

三.返回值定義

本項目需要兩種返回類型谅将，一種是秒殺接口暴露漾狼，另一種是秒殺結(jié)果。
1.秒殺接口暴露的返回值

public class Exposer {
    //是否開其秒殺
    private boolean exposed;
    
    private String md5;
    private long seckillId;
    //當(dāng)前時間
    private long now;
    //開啟時間
    private long start;
    //結(jié)束時間
    private long end;
    public Exposer(boolean exposed, String md5, long seckillId) {
        super();
        this.exposed = exposed;
        this.md5 = md5;
        this.seckillId = seckillId;
    }
    public Exposer(boolean exposed, long seckillId) {
        super();
        this.exposed = exposed;
        this.seckillId = seckillId;
    }
    public Exposer(boolean exposed, long seckillId,long now, long start, long end) {
        super();
        this.exposed = exposed;
        this.now = now;
        this.seckillId=seckillId;
        this.start = start;
        this.end = end;
    }
    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;
    }
    

}

2.秒殺結(jié)果

public class SeckillExecution {
    private long SeckillId;
    //秒殺狀態(tài)
    private int state;
    private  String stateInfo;
    private SuccessKilled successKilled;
    
    public SeckillExecution(long seckillId, SeckillStatEnum statEnum) {
        super();
        SeckillId = seckillId;
        this.state = statEnum.getState();
        this.stateInfo = statEnum.getStateInfo();
    }
    public SeckillExecution(long seckillId, SeckillStatEnum statEnum, SuccessKilled successKilled) {
        super();
        SeckillId = seckillId;
        this.state = statEnum.getState();
        this.stateInfo = statEnum.getStateInfo();
        this.successKilled = successKilled;
    }
    public long getSeckillId() {
        return SeckillId;
    }
    public void setSeckillId(long seckillId) {
        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;
    }
    
}

四.秒殺service

1.秒殺service接口主要有四個方法饥臂，秒殺列表查詢逊躁，單個商品信息查詢，秒殺地址暴露擅笔，秒殺執(zhí)行志衣。

public interface SeckillService {
    /**
     * 查詢所有秒殺的記錄
     * @return 
     */
    public List<Seckill> getScekillList();
    /**
     * 查詢耽擱秒殺
     */
    public Seckill getSeckillById(long seckillId);
    /**
     * 秒殺借口 秒殺開啟時輸出地址否則輸出系統(tǒng)時間和接口時間
     */
    public Exposer  exportSeckillUrl(long seckillId);
    /**
     * 執(zhí)行秒殺
     */
    SeckillExecution  executeSeckill(long seckillId,long userPhone ,String md5)
    throws SeckillException,RepeatKillException,SeckillCloseException;
}

2.接口實現(xiàn)

package com.wen.seckill.service.impl;

import java.util.Date;
import java.util.List;

import javax.annotation.Resource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import com.wen.seckill.dao.SeckillDao;
import com.wen.seckill.dao.SuccessKilledDao;
import com.wen.seckill.dto.Exposer;
import com.wen.seckill.dto.SeckillExecution;
import com.wen.seckill.enums.SeckillStatEnum;
import com.wen.seckill.exception.RepeatKillException;
import com.wen.seckill.exception.SeckillCloseException;
import com.wen.seckill.exception.SeckillException;
import com.wen.seckill.model.Seckill;
import com.wen.seckill.model.SuccessKilled;
import com.wen.seckill.service.SeckillService;
@Service("seckillService")
public class SeckillServiceImpl implements  SeckillService{
    private Logger logger = (Logger) LoggerFactory.getLogger(SeckillServiceImpl.class);
    @Resource(name="seckillDao")
    private SeckillDao seckillDao;
    @Resource(name="successKilledDao")
    private SuccessKilledDao successKilledDao;
    public final String slat="dfaf23asascxcaser23ads";
    /**
     * 查詢所有秒殺的記錄
     * @return 
     */
    public List<Seckill> getSeckillList(){
        return seckillDao.queryAll();
    }
    /**
     * 查詢耽擱秒殺
     */
    public Seckill getSeckillById(long seckillId) {
        return seckillDao.queryById(seckillId);
    }
    /**
     * 秒殺借口 秒殺開啟時輸出地址否則輸出系統(tǒng)時間和接口時間
     */
    public Exposer  exportSeckillUrl(long seckillId) {
        Seckill seckill=seckillDao.queryById(seckillId);
        if(seckill==null) {
            return new Exposer(false,seckillId);
        }else {
            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());
            }else {
                String md5=getMD5(seckillId);
                return new Exposer(true,md5,seckillId);
            } 
        }
            
    }
    /**
     * 執(zhí)行秒殺
     */
    @Transactional
    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");
        }
        //執(zhí)行秒殺
        Date nowTime=new Date();
        try {
            int updateCount=seckillDao.reduceNumber(seckillId, nowTime);
            if(updateCount<=0) {
                //沒有更新dao
                //throw new SeckillCloseException("seckill id closed");
                return new SeckillExecution(seckillId,SeckillStatEnum.FAIL_Kill);
            }else {
                //減庫存成功
                //記錄購買行為
                int insertCount=successKilledDao.insertSuccessKilled(seckillId, userPhone);
                if(insertCount<=0) {
                    //重復(fù)秒殺
                    //throw new RepeatKillException("seckill id repeated");
                    return new SeckillExecution(seckillId,SeckillStatEnum.REPEAT_KILL);
                }else {
                    
                    SuccessKilled success=successKilledDao.queryByIdWithSeckill(seckillId, userPhone);
                    return new SeckillExecution(seckillId,SeckillStatEnum.SUCCESS,success);
                }
            }   
        }catch(Exception e) {
            e.printStackTrace();
            throw new SeckillException("seckill inner error"+e.getMessage());
        }
        
    }
    private String getMD5(long seckillId) {
        String base=seckillId+"/"+slat;
        String md5=DigestUtils.md5DigestAsHex(base.getBytes());
        return md5;
    }
}

由于需要執(zhí)行減庫存以及插入秒殺記錄的造作需要事務(wù)這里我們用注解的方式來控制事務(wù)。注解事務(wù)主要有如下的優(yōu)點猛们。
(1).開發(fā)團隊達成一致約定念脯，明確標(biāo)注事務(wù)的編程風(fēng)格。
(2).保證事務(wù)的執(zhí)行時間盡可能的短弯淘，不要穿插其他網(wǎng)絡(luò)操作如RPC/HTTP請求或者剝離到事務(wù)的外圍绿店。
(3).不是所有的方法都需要事務(wù)，只有一條記錄要修改庐橙，只讀操作不需要事務(wù)假勿。

五.單元測試

編寫單元測試的方法測試所寫的service 類

public class SeckillServiceImplTest extends BaseTest {

    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 {
        long id = 1000;
        Seckill seckill = seckillService.getSeckillById(id);
        logger.info("seckill={}", seckill);
    }

    // 測試代碼完整邏輯，注意可重復(fù)執(zhí)行
    @Test
    public void testSeckillLogic() throws Exception {
        long id = 1002;
        Exposer exposer = seckillService.exportSeckillUrl(id);
        if (exposer.isExposed()) {
            logger.info("exposer={}", exposer);
            long phone = 13631231234L;
            String md5 = exposer.getMd5();
            try {
                SeckillExecution execution = seckillService.executeSeckill(id, phone, md5);
                logger.info("execution={}", execution);
            } catch (RepeatKillException e) {
                logger.error(e.getMessage());
            } catch (SeckillCloseException e) {
                logger.error(e.getMessage());
            }catch (Exception e) {
                e.printStackTrace();
                logger.error(e.getMessage());
            }
        } else {
            // 秒殺未開啟
            logger.error("exposer={}", exposer);
        }
    }

    @Test
    public void testExecuteSeckillProcedure() throws Exception {
        long seckillId = 1003;
        long phone = 13631231234L;
        Exposer exposer = seckillService.exportSeckillUrl(seckillId);
        if (exposer.isExposed()) {
            String md5 = exposer.getMd5();
            SeckillExecution execution = seckillService.executeSeckill(seckillId, phone, md5);
            logger.info(execution.getStateInfo());
        }
    }

}

文章地址 ：http://www.haha174.top/article/details/251844
源碼地址 ：https://github.com/haha174/seckill.git
教程地址 ：http://www.imooc.com/learn/631