學(xué)會(huì)了如果使用quartz，也研究quartz的底層源碼，寫(xiě)一個(gè)需求能夠?qū)uartz更融會(huì)貫通。我在用spring boot quartz的時(shí)候，發(fā)現(xiàn)所有的jobDetail和trigger的配置都是一樣的，除了定時(shí)時(shí)間不一樣之外，其他的都是一樣的，為了減少bena的配置，能不能在寫(xiě)job類(lèi)的時(shí)候，增加一個(gè)注解，然后能夠自動(dòng)注入到spring bean中。還有quartz沒(méi)有記錄運(yùn)行日志，不知道到底運(yùn)行了沒(méi)有，運(yùn)行結(jié)果如何，如果增加一張日志表，記錄quartz的運(yùn)行日志。

1. 注解注冊(cè)job

1.1 思路

要能夠自動(dòng)注入bean，spring boot是如何做的？我想起了spring boot mybatis的做法，定義一個(gè)MapperScan注解，MapperScan注解中有一個(gè)@Import(MapperScannerRegistrar.class)， 在Spring boot啟動(dòng)的時(shí)候會(huì)加載MapperScannerRegistrar注冊(cè)bean。我們是不是也可以按照這個(gè)思路。

1. 定義一個(gè)注解EnableQuartzScheduled，也寫(xiě)一個(gè)Registrar可以讓Spring掃描所有的job，job上定義一個(gè)注解，設(shè)置trigger的時(shí)間。

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Import(QuartzScheduledRegistrar.class)
public @interface EnableQuartzScheduled {

    /**
     * 掃描的基礎(chǔ)包
     * @return
     */
    String basePackage() default "";
}

2. job上的注解QuartzScheduled

@Documented
@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
public @interface QuartzScheduled {
    String cron();
}

這里有個(gè)問(wèn)題就是spring如何去掃描包，并加載類(lèi)的，這塊我研究了spring mybatis的源碼，是利用ClassPathScanningCandidateComponentProvider類(lèi)，設(shè)置掃描包名，過(guò)濾條件(因?yàn)椴皇撬械念?lèi)都需要加載成bean的)

public class QuartzScheduledRegistrar implements ImportBeanDefinitionRegistrar, ResourceLoaderAware, BeanClassLoaderAware, EnvironmentAware, BeanFactoryAware {

    protected final Log logger = LogFactory.getLog(getClass());

    private Environment environment;

    private BeanFactory beanFactory;

    private ClassLoader classLoader;

    @Override
    public void setBeanClassLoader(ClassLoader classLoader) {
        this.classLoader = classLoader;
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        this.beanFactory = beanFactory;
    }

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = environment;
    }

    @Override
    public void setResourceLoader(ResourceLoader resourceLoader) {

    }

    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        AnnotationAttributes annoAttrs =  AnnotationAttributes.fromMap(importingClassMetadata.getAnnotationAttributes(EnableQuartzScheduled.class.getName()));
        for (String pkg : annoAttrs.getStringArray("basePackage")) {
            if (StringUtils.hasText(pkg)) {
                registerQuartzScheduled(pkg);
            }
        }
    }

    private void registerQuartzScheduled(String basePackage) {
        //掃描所有的類(lèi)
        ClassPathScanningCandidateComponentProvider classScanner = new ClassPathScanningCandidateComponentProvider(false, this.environment);
        AnnotationTypeFilter  annotationTypeFilter = new AnnotationTypeFilter(QuartzScheduled.class);
        classScanner.addIncludeFilter(annotationTypeFilter);
        Set<BeanDefinition> beanDefinitionSet = classScanner.findCandidateComponents(basePackage);
        if (beanDefinitionSet == null || beanDefinitionSet.isEmpty()) {
            return;
        }
        for (BeanDefinition beanDefinition : beanDefinitionSet) {
            if (beanDefinition instanceof AnnotatedBeanDefinition) {
                registerBeans(((AnnotatedBeanDefinition) beanDefinition));
            }
        }
     }

    private void registerBeans(AnnotatedBeanDefinition annotatedBeanDefinition) {
        String className = annotatedBeanDefinition.getBeanClassName();
        //得到j(luò)ob上的注解
        AnnotationMetadata metadata = annotatedBeanDefinition.getMetadata();
        AnnotationAttributes annoAttrs =  AnnotationAttributes.fromMap(metadata.getAnnotationAttributes(QuartzScheduled.class.getName()));
        //獲取注解上cron的值
        String cron = annoAttrs.getString("cron");
        if (StringUtils.isEmpty(cron) || !CronExpression.isValidExpression(cron)) {
            logger.error(className + " @QuartzScheduled cron error");
            return;
        }
        try {
            Class jobClass = ClassUtils.forName(annotatedBeanDefinition.getMetadata().getClassName(), classLoader);
            //生成jobDetail
            JobDetail jobDetail = JobBuilder.newJob(jobClass).storeDurably().withIdentity(jobClass.getSimpleName() + "_jobDetail").build();
            //生成trigger
            CronScheduleBuilder cronScheduleBuilder = CronScheduleBuilder.cronSchedule(cron).withMisfireHandlingInstructionIgnoreMisfires();
            CronTrigger cronTrigger = TriggerBuilder.newTrigger().forJob(jobDetail).withIdentity(jobClass.getSimpleName() + "_trigger").withSchedule(cronScheduleBuilder).build();
            //注冊(cè)bean
            ((DefaultListableBeanFactory) this.beanFactory).registerSingleton(jobClass.getSimpleName() + "_jobDetail", jobDetail);
            ((DefaultListableBeanFactory) this.beanFactory).registerSingleton(jobClass.getSimpleName() + "_trigger", cronTrigger);
        } catch (Exception e) {
            logger.error("register" + className + " error", e);
        }

    }
}

2. 記錄日志

當(dāng)初想的就是能夠把quartz運(yùn)行的日志記錄到數(shù)據(jù)庫(kù)，能夠在界面上展示出來(lái)，這里代碼沒(méi)寫(xiě)全，只是寫(xiě)了個(gè)思路。在閱讀源碼后，發(fā)現(xiàn)quartz在運(yùn)行job前后都會(huì)通知監(jiān)聽(tīng)器，如果我們加一個(gè)job的監(jiān)聽(tīng)器，是不是就可以實(shí)現(xiàn)日志記錄了。在這遇到兩個(gè)問(wèn)題。

1. quartz如何寫(xiě)監(jiān)聽(tīng)器
2. spring boot quartz是如何增加監(jiān)聽(tīng)器的

2.1 quartz編寫(xiě)job監(jiān)聽(tīng)器

開(kāi)源框架，為了擴(kuò)展性，基本都會(huì)定義一個(gè)接口，直接繼承接口就能夠使用了,quartz也不例外，我們實(shí)現(xiàn)JobListener就可以了。記錄日志就要操作數(shù)據(jù)庫(kù)。數(shù)據(jù)源使用和quartz使用同一個(gè)，@QuartzDataSource標(biāo)注quartz的數(shù)據(jù)源。

表結(jié)構(gòu)：

@Component
public class QuartzJobLogListener implements JobListener {
    protected final Log logger = LogFactory.getLog(getClass());

    @Autowired
    @QuartzDataSource
    private DataSource dataSource;
    private static final String INSERT_SQL = "insert into QRTZ_LOG(JOB_NAME, status, errMsg, createdate, modifytime) " +
            "values(?, ?, ?, now() ,now())";

    @Override
    public String getName() {
        return "QuartzJobLogListener";
    }

    @Override
    public void jobToBeExecuted(JobExecutionContext context) {
        //logger.info(context.getJobDetail().getKey() + "jobToBeExecuted...");
    }

    @Override
    public void jobExecutionVetoed(JobExecutionContext context) {

    }

    @Override
    public void jobWasExecuted(JobExecutionContext context, JobExecutionException jobException) {
        logger.info(context.getJobDetail().getKey() + "jobWasExecuted..." + context.getJobRunTime());
        int status = 1;
        String errMsg = null;
        if (jobException != null) {
            status = 0;
            errMsg = jobException.getMessage();
        }
        saveLog(context.getJobDetail().getKey().getName(), status, errMsg);
    }

    private void saveLog(String jobName, int status, String errorMsg) {
        try (Connection connection = dataSource.getConnection()){
            PreparedStatement ps = connection.prepareStatement(INSERT_SQL);

            ps.setString(1, jobName);
            ps.setInt(2, status);
            ps.setString(3, errorMsg);
            ps.execute();

        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

2.2 監(jiān)聽(tīng)器如何與spring boot結(jié)合

spring boot quartz在加載的時(shí)候，會(huì)去加載所有的SchedulerFactoryBeanCustomizer，并把值注入到SchedulerFactoryBean中，代碼邏輯在QuartzAutoConfiguration#customize中。所以只需下面這么做就好了

@Configuration
public class QuartzListenerConfiguration {

    @Bean
    public SchedulerFactoryBeanCustomizer listenerCustomizer() {
        return schedulerFactoryBean -> schedulerFactoryBean.setGlobalJobListeners(new QuartzJobLogListener());
    }
}