SSM，Spring,SpringMVC,Mybatis之Service---29

SSM之Service---29

Spring/SpringMVC/Mybatis，日志

Service文件夹：

exception：异常包,创建公版异常(SeckillException)，其他异常进行继承

dao：主要面向与业务无关的，和如Hibernate、MyBatis相关的事务操作。
dto(数据传输)，类似entity，侧重于存放跟web交互的实体类，(做为service的返回类型使用)

service放与业务逻辑相关的事务操作（接口）； 

Service代码(包括service(接口)，dto，exception)：

service文件(接口)：

@SeckillService.java/** * 业务接口：站在“使用者”角度设计接口 * 三个方面：方法定义的粒度（明确使用者要使用的方法）， * 参数（简单直接，少用Map）， * 返回类型（return 类型简单，少用Map /异常） */public interface SeckillService {/** * 查询所有秒杀记录 * @return */List<Seckill> getSeckillList();/** * 查询单个秒杀记录 * @param seckillId * @return */Seckill getSeckillById(long seckillId);/** * 秒杀开启时输出渺少接口地址， * 否则输出系统时间和秒杀时间 * @param seckillId *  @return Exposer */Exposer exportSeckillUrl(long seckillId);/** * 执行秒杀操作 * @param seckillId * @param userPhone * @param md5 * @return SeckillExecution */SeckillExecution executeSeckill(long seckillId,long userPhone,String md5)throws SeckillException,RepeatKillException,SeckillCloseException;}

dto文件(包含Service实现所需要的属性)：

@Exposer.java /*** 暴露秒杀地址DTO * @author THHINK * */public class Exposer {//是否开启秒杀private boolean exposed;//秒杀IDprivate long seckillId;//一种加密措施private String md5;//系统当前时间（毫秒）private long now;//开始时间private long start;//结束时间private long end;public Exposer(boolean exposed, long seckillId, String md5) {super();this.exposed = exposed;this.seckillId = seckillId;this.md5 = md5;}public Exposer(boolean exposed, long now, long start, long end) {super();this.exposed = exposed;this.now = now;this.start = start;this.end = end;}public Exposer(boolean exposed, long seckillId) {super();this.exposed = exposed;this.seckillId = seckillId;}

@SeckillException.java/** * 封装秒杀执行后的结果 * @author THHINK * */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, int state, String stateInfo, SuccessKilled successKilled) {super();this.seckillId = seckillId;this.state = state;this.stateInfo = stateInfo;this.successKilled = successKilled;}public SeckillExecution(long seckillId, int state, String stateInfo) {super();this.seckillId = seckillId;this.state = state;this.stateInfo = stateInfo;}

exception文件(各种异常，一个公版，其他继承);

@SeckillException.java/** * 秒杀相关业务异常 */public class SeckillException extends RuntimeException {public SeckillException(String message){super(message);}public SeckillException(String message,Throwable cause){super(message,cause);}

@SeckillCloseException.java/** * 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);}}

@RepeatKillException.java/** * 重复秒杀异常（运行期异常--不需要手动try Catch） * spring的事务只接收 运行期异常，并进行回滚。 */public class RepeatKillException extends SeckillException {public RepeatKillException(String message){super(message);}public RepeatKillException(String message,Throwable cause){super(message,cause);}

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使用枚举表示数据常量字段，方便维护

定义枚举格式

/** *使用枚举 表述常量数据字段 */public enum SeckillStatEnum {SUCCESS(1,"秒杀成功"),END(0,"秒杀结束"),REPEAT_KILL(-1,"重复秒杀"),INNER_ERRPR(-2,"系统异常"),Data_REWEITE(-3,"数据篡改");private int state;private String stateInfo;private 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;}}

实现SeckillService接口---SeckillServiceImpl实现类。

@SeckillServiceImpl.java

@Service("seckillService")public class SeckillServiceImpl implements SeckillService {private Logger logger = LoggerFactory.getLogger(this.getClass());//注入Service依赖@Autowired//@Resource,@Injectprivate SeckillDao seckillDao;@Autowiredprivate SuccessKilledDao successKilledDao;@Autowiredprivate RedisDao redisDao;@Resourceprivate SeckillUtil seckillUtil;public List<Seckill> getSeckillList() {return seckillDao.queryAll(0, 4);}public Seckill getSeckillById(long seckillId) {return seckillDao.queryById(seckillId);}public Exposer exportSeckillUrl(long seckillId) {//优化点:缓存优化:超时的基础上维护一致性(数据不变的情况,多并发)//1:访问redisSeckill seckill = redisDao.getSeckill(seckillId);if (seckill == null) {//2:访问数据库seckill = seckillDao.queryById(seckillId);if(seckill != null){//3:放入redisString result = redisDao.putSeckill(seckill);System.out.println("result"+result);seckill = redisDao.getSeckill(seckillId);System.out.println("seckill="+seckill);}else{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());}// 转换特定字符串的过程，不可逆String md5 = seckillUtil.getMD5(seckillId);return new Exposer(true, seckillId, md5);}/** * 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，只读操作不需要事务控制 */@Transactionalpublic SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)throws SeckillException, RepeatKillException, SeckillCloseException {System.out.println("执行executeSeckill。。。");if (md5 == null || !md5.equals(seckillUtil.getMD5(seckillId))) {throw new SeckillException("seckill data rewrite");}Date killTime = new Date();// 执行秒杀逻辑：减库存+记录秒杀行为（一个事务（运行期），出现问题，回滚）try {// 记录购买行为int insertCount = successKilledDao.insertSuccessKilled(seckillId, userPhone);// 唯一验证：seckillId,userPhone// 重复秒杀if (insertCount <= 0){throw new RepeatKillException("seckill repeated");} else {// 减库存 ,热门商品竞争System.out.println("减库存。。。");int updateCount = seckillDao.reduceNumber(seckillId, killTime);System.out.println("减库存完成");if (updateCount <= 0) {//没有更新到记录，秒杀结束，rollbackthrow new SeckillCloseException("seckill is closed");} else {// 秒杀成功 commitSuccessKilled successKilled = successKilledDao.queryByIdWithSeckill(seckillId, userPhone);return new SeckillExecution(seckillId,SeckillStateEnum.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());}}public SeckillExecution executeSeckillProcedure(long seckillId, long userPhone, String md5) {if (md5 == null || !md5.equals(seckillUtil.getMD5(seckillId))) {return new SeckillExecution(seckillId, SeckillStateEnum.DATA_REWRITE);}Date killTime = new Date();Map<String, Object> map = new HashMap<String, Object>();map.put("seckillId", seckillId);map.put("phone", userPhone);map.put("killTime", killTime);map.put("result", null);// 执行存储过程，result被赋值try {seckillDao.killByProcedure(map);//commons-collections， 获取resultint result = MapUtils.getInteger(map, "result", -2);if (result == 1) {SuccessKilled sk = successKilledDao.queryByIdWithSeckill(seckillId, userPhone);return new SeckillExecution(seckillId, SeckillStateEnum.SUCCESS, sk);} else {return new SeckillExecution(seckillId, SeckillStateEnum.stateOf(result));}} catch (Exception e) {logger.error(e.getMessage(), e);return new SeckillExecution(seckillId, SeckillStateEnum.INNER_ERROR);}}}

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Spring管理Service依赖：

Spring IOC理解：

使用Spring IOC可以得到一致的访问接口，通过接口可以访问工厂中任意实例。

业务对象依赖图：Spring了一个完整初始化的过程，我们能从Spring中得到SeckillService完整的实例。

为什么用IOC：
1：对象创建统一托管2：规范的生命周期管理3：灵活的依赖注入4：一致的获取对象

深刻理解IOC的依赖注入以及注入场景使用

IOC配置流程：XML配置 -> package-scan(包扫描)  ->  Annotation 注解

声明式事务：

声明式事务目的在于解脱繁琐的关于事务的代码，

在实际的开发中，不需要关心事务的开启、提交、回滚、关闭等等，而是直接交由第三方框架托管，比如spring。

第二中方法：tx:advice+aop命名空间（一次配置永久生效）
第三中方法：@Transactional（注解控制）

本例推荐使用第三种基于注解的声明式事务的方法，这种方式的优点在于，当看到@Transcation注解的时候知道这是一个与事务有关的方法，此时就会自觉遵守一些关于事务开发的规范，有利于程序的进一步维护。

Spring在抛出运行期异常时会回滚事务，两点注意：
1 非运行期异常时要注意，防止出现部分成功部分失败的情况（所以自己封装异常时，在需要的地方要implements RuntimeException）。2 小心使用try-catch：被try-catch块包裹起来的异常Spring也是感觉不到的。

Spring 管理Service依赖：

@spring-service.xml<?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"xmlns:util="http://www.springframework.org/schema/util" xmlns:jee="http://www.springframework.org/schema/jee"xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jpa="http://www.springframework.org/schema/data/jpa"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsdhttp://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsdhttp://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsdhttp://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsdhttp://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd "><!--扫描service包下所有使用注解的类型Service,Controller --><context:component-scan base-package="org.seckill.service"/><!-- 配置事务管理器 --><bean id="txManager"class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource"/><!--注入数据连接池--></bean><!-- 配置基于注解的声明式事务 默认使用注解管理事务行为 @Transactional --><tx:annotation-driven transaction-manager="txManager" /> </beans>

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编写测试类

配置日志：

logback官方配置网页http://logback.qos.ch/manual/configuration.html

@logback.xml<?xml version="1.0" encoding="UTF-8" ?><configuration debug="true"><appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"><!-- encoders are by default assigned the type ch.qos.logback.classic.encoder.PatternLayoutEncoder --><encoder><pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern></encoder></appender><root level="debug"><appender-ref ref="STDOUT" /></root></configuration>

@SeckillServiceTest.java@RunWith(SpringJUnit4ClassRunner.class)//告诉Junit spring配置文件@ContextConfiguration(locations={"classpath:spring/spring-dao.xml","classpath:spring/spring-service.xml"})public class SeckillServiceTest {private final Logger logger = LoggerFactory.getLogger(this.getClass());@Autowiredprivate SeckillService seckillService;@Testpublic void testGetSeckillList() {List<Seckill> seckills= seckillService.getSeckillList();logger.info("seckills={}",seckills);}@Testpublic void testGetSeckillById() {long seckillId = 1002;Seckill seckill = seckillService.getSeckillById(seckillId);logger.info("seckill={}", seckill);}@Testpublic void testExportSeckillUrl() {long seckillId = 1000;Exposer exposer =seckillService.exportSeckillUrl(seckillId);logger.info("exposer={}", exposer);}@Testpublic void testExecuteSeckill() {long seckillId = 1000;long userPhone = 13022211112L;String md5="018bd79f607030689c3b18cd4c03f7e3";try {SeckillExecution seckillExecution =seckillService.executeSeckill(seckillId, userPhone, md5);logger.info("seckillExecution={}", seckillExecution);} catch (RepeatKillException e) {e.printStackTrace();} catch (SeckillCloseException e) {e.printStackTrace();} }//集成测试代码完整逻辑，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 = 13022211113L;String md5=exposer.getMd5();try {SeckillExecution seckillExecution =seckillService.executeSeckill(seckillId, userPhone, md5);logger.info("seckillExecution={}", seckillExecution);} catch (RepeatKillException e) {e.printStackTrace();} catch (SeckillCloseException e) {e.printStackTrace();} }else{//秒杀未开启logger.warn("exposer={}",exposer);}}}