Java Scala获取所有注解的类信息-白红宇

Java Scala获取所有注解的类信息

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发布时间：2019-06-13

本文共 12063 字，大约阅读时间需要 40 分钟。

要想获取使用指定注解的类信息，可借助工具：

org.reflections.Reflections

此工具将Java反射进行了高级封装，Reflections 通过扫描 classpath，索引元数据，允许在运行时查询这些元数据，也可以保存收集项目中多个模块的元数据信息。

使用 Reflections 可以查询以下元数据信息：

1）获得某个类型的所有子类型2）获得标记了某个注解的所有类型／成员变量，支持注解参数匹配。3）使用正则表达式获得所有匹配的资源文件4）获得所有特定签名（包括参数，参数注解，返回值）的方法

Reflections 依赖 Google 的库和库。

Maven引入方式：


         
      
       org.reflections
          
      
       reflections
          
      
       0.9.11

sbt引入方式：

"org.reflections" % "reflections" % "0.9.11"

首先自定义注解：

package com.today.service.financetask.job

import java.lang.annotation.*;/** * 类功能描述：job 信息注解 * * @author WangXueXing create at 19-5-4 上午9:14 * @version 1.0.0 */@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Inheritedpublic @interface JobInfo {    /**     * job id     * @return     */    String jobId();    /**     * job name     * @return     */    String jobName();    /**     * default cron     * @return     */    String defaultCron();}

将某些类添加注解：

package com.today.service.financetask.job

import java.util.Calendarimport com.today.api.checkaccount.scala.CheckAccountServiceClientimport com.today.api.checkaccount.scala.enums.FlatFormTypeEnumimport com.today.api.checkaccount.scala.request.ReconciliationRequestimport com.today.service.financetask.job.define.AbstractJobimport com.today.service.financetask.utils.JobInfoimport org.quartz.JobExecutionContext/**  * 自动对账  */@JobInfo(jobId="CHECK_ACCOUNT_PROCESS", jobName="对账系统自动对账定时任务", defaultCron="0 0 13 * * ?")class CheckAccountJob extends AbstractJob{  /**    * start up the scheduled task    *    * @param context JobExecutionContext    */  override def run(context: JobExecutionContext): Unit = {    val cal = Calendar.getInstance    cal.add(Calendar.DATE, -1)    new CheckAccountServiceClient().appReconciliation(new ReconciliationRequest(FlatFormTypeEnum.TODAY_APP,None))  }}

import com.today.service.financetask.action.DailyStatementActionimport com.today.service.financetask.job.define.AbstractJobimport com.today.service.financetask.utils.JobInfoimport org.quartz.JobExecutionContextimport org.springframework.stereotype.Service/**  * 日次处理定时任务处理  *  * @author zhangc create at 2018/5/11 14:08  * @version 0.0.1  */@Service@JobInfo(jobId="DAY_TIME_PROCESS", jobName="日次处理定时任务", defaultCron="0 30 2 * * ?")class DayTimeProcessJob extends AbstractJob{  /**    * start up the scheduled task    *    * @param context JobExecutionContext    */  override def run(context: JobExecutionContext): Unit = {    new DailyStatementAction().execute  }}

通过Java反射及Reflections工具类实现被JobInfo注解的所有类信息：

import java.utilimport com.today.service.financetask.utils.JobInfoimport org.quartz.Jobimport org.reflections.Reflectionsimport scala.collection.JavaConverters._import scala.collection.mutable/**  * 通过注解获取所有通用Job信息  *  * @author BarryWang create at 2018/5/12 10:45  * @version 0.0.1  */object JobEnum {  /**    * 获取添加JobInfo注解的类信息    */  val jobWithAnnotation: util.Set[Class[_]] = new Reflections("com.today.service.financetask.job").getTypesAnnotatedWith(classOf[JobInfo])  /**    * 获取所有job枚举值    * @return    */  def values : mutable.Set[JobInfo] = jobWithAnnotation.asScala.map(getJobInfo(_))  /**    * 根据job class 获取job 信息    * @param jobClass    * @return    */  def getJobInfo(jobClass : Class[_]): JobInfo = jobClass.getAnnotation(classOf[JobInfo])  /**    * jobId与jobName映射关系    * @return    */  def jobIdNameMap : Map[String, String]={    jobWithAnnotation.asScala.map{sub =>      val jobInfo = getJobInfo(sub)      Map(jobInfo.jobId() -> jobInfo.jobName())    }.fold(Map())((i,j) => i++j)  }  /**    * JobObject与JobEnum映射关系    * @return    */  def jobClassInfoMap: Map[String, JobInfo] = {    jobWithAnnotation.asScala.map{sub =>      Map(sub.getName -> getJobInfo(sub))    }.fold(Map())((i,j) => i++j)  }  /**    * jobId与JobEnum映射关系    * @return    */  def jobIdInfoMap: Map[String, JobInfo] = {    jobWithAnnotation.asScala.map{sub =>      val jobInfo = getJobInfo(sub)      Map(jobInfo.jobId() -> jobInfo)    }.fold(Map())((i,j) => i++j)  }  /**    * jobId与JobObject映射关系    * @return    */  def jobIdClassMap: Map[String, Class[_ <: Job]] = {    jobWithAnnotation.asScala.map{sub =>      Map(getJobInfo(sub).jobId() -> sub.asInstanceOf[Class[_ <: Job]])    }.fold(Map[String, Class[_ <: Job]]())((i,j) => i++j)  }  def main(args: Array[String]): Unit = {    println(jobIdClassMap)  }}

至此，我们就可以获取所有被特定注解引用的类信息及注解信息，我们就可以全局管理特定类信息。

实现JobEnum后就可以统一对定时任务管理实现：

１．新添加定时任务完全可以制定一个Job子类，其他操作自动维护进去；

２．每个Job子类里面都需要实现 override def getJobAndApiInfo(context: JobExecutionContext): (String, String, JobEnum) 方法，这个也可以省掉，直接在父类统一实现；

３．统一修改定时任务开关及时间接口；

４．统一对定时任务启动时重启，就可以统一重启，不需要单独添加代码启动；

1上面代码片段“将某些类添加注解”

2父类代码如下：

import java.io.{PrintWriter, StringWriter}import com.github.dapeng.core.helper.MasterHelperimport com.today.api.financetask.scala.enums.TScheduledTaskLogEnumimport com.today.service.financetask.action.sql.ScheduledTaskLogSqlimport com.today.service.financetask.util.{AppContextHolder, Debug}import com.today.service.financetask.utils.JobInfoimport org.quartz.{Job, JobExecutionContext}import org.slf4j.LoggerFactoryimport org.springframework.transaction.TransactionStatusimport org.springframework.transaction.support.TransactionTemplateimport scala.util.{Failure, Success, Try}/**  * the abstract class for job  */trait AbstractJob extends Job{  /** 日志 */  val logger = LoggerFactory.getLogger(getClass)  /**    * execute the job    * @param context    */  override def execute(context: JobExecutionContext): Unit = {    getJobAndApiInfo(context) match {      case Some(x) => execute(context, x.jobId, x.jobName)      case None => logger.error("没有定义JobEnum及对应JobObject，请检查")    }  }  /**    * execute the job    * @param context    * @param jobId    * @param jobName    */  def execute(context: JobExecutionContext, jobId : String, jobName: String): Unit = {    //判断是否是选中的master节点，不是master节点不执行定时任务    if (!MasterHelper.isMaster("com.today.api.financetask.service.FinanceScheduledService", "1.0.0")) {      logger.info(s"Can't select master to run the job ${jobId}: ${jobName}")      return    }    //记录开始日志    val logId = ScheduledTaskLogSql.insertScheduledTaskLog(jobId)    context.put("logId", logId)    logger.info(s"Starting the job ${jobId}: ${jobName} ...")    //事物处理    val transactionTemplate: TransactionTemplate = AppContextHolder.getBean("transactionTemplate")    transactionTemplate.execute((status: TransactionStatus) =>{      Debug.reset()      //执行任务      Try(Debug.trace(s"${jobId}:${jobName}")(run(context))) match      {        case Success(x) => {          logger.info(s"Successfully execute the job ${jobId}: ${jobName}")          successLog(logId)        }        case Failure(e) => {          logger.error(s"Failure execute the job ${jobId}: ${jobName}", e)          failureLog(logId, status, e)        }      }      Debug.info()    })  }  /**    * get the api information    * @return (interface name, interface version, JobEnum)    */  def getJobAndApiInfo(context: JobExecutionContext) : Option[JobInfo] ={    JobEnum.jobClassInfoMap.get(this.getClass.getName)  }  /**    * start up the scheduled task    * @param context JobExecutionContext    */  def run(context: JobExecutionContext)  /**    * 成功日志记录    * @param logId    */  def successLog(logId: Long): Unit ={    ScheduledTaskLogSql.updateExportReportRecord(logId, TScheduledTaskLogEnum.SUCCESS, "Success")  }  /**    * 失败日志记录    * @param logId    */  def failureLog(logId: Long, status: TransactionStatus, e: Throwable): Unit ={    status.setRollbackOnly()    ScheduledTaskLogSql.updateExportReportRecord(logId, TScheduledTaskLogEnum.FAILURE, getExceptionStack(e))  }  /**    *    * 功能说明:在日志文件中 ，打印异常堆栈    * @param e : Throwable    * @return : String    */  def getExceptionStack(e: Throwable): String = {    val errorsWriter = new StringWriter    e.printStackTrace(new PrintWriter(errorsWriter))    errorsWriter.toString  }}

3 统一修改定时任务开关及时间代码如下：

import com.today.api.financetask.scala.enums.{TScheduledTaskHasDeletedEnum, TScheduledTaskIsStartEnum}import com.today.api.financetask.scala.request.StartOrStopByNameRequestimport com.today.api.financetask.scala.response.ServiceResponseimport com.today.service.commons.Actionimport com.today.service.commons.Assert.assertimport com.today.service.commons.exception.CommonException.illegalArgumentExceptionimport com.today.service.financetask.action.sql.ScheduledTaskActionSqlimport com.today.service.financetask.dto.TScheduledTaskimport com.today.service.financetask.job.define.JobEnumimport com.today.service.financetask.query.sql.ScheduledTaskQuerySqlimport com.today.service.financetask.util.{CronConverter, QuartzManager}/**  * @description: 启停定时任务  * @author zhangc  * @date 2018\8\1 0001 15:02  * @version 1.0.0  */class StartOrStopByNameAction (request: StartOrStopByNameRequest)  extends Action[ServiceResponse] {  override def preCheck: Unit = {    assert(!TScheduledTaskIsStartEnum.isUndefined(request.flag.id), illegalArgumentException("错误的启停标志!"))  }  /**    * 根据传入的定时任务名称和启停标志，来判断启动或者停止定时任务    * 如果是1则更新数据库，删除定时任务，重新添加定时任务    * 如果是0则更新数据库，删除定时任务    * @return    */  override def action: ServiceResponse = {    val scheduledTask = ScheduledTaskQuerySql.queryByJobId(request.processName)    val cron = CronConverter.convertHourMinuteToCron(request.processTime)    val jobInfo = JobEnum.jobIdInfoMap(request.processName)    //修改定时任务时间, 保存入库    if(scheduledTask.isEmpty){      ScheduledTaskActionSql.insertTScheduledTask(        TScheduledTask(jobInfo.jobName,          request.processName,          cron,          None,          request.flag.id,          None,          null,          null,          TScheduledTaskHasDeletedEnum.NO.id))    } else {      ScheduledTaskActionSql.updateTaskIsStart(request.flag.id,cron, request.processName)    }    request.flag match {      case TScheduledTaskIsStartEnum.YES =>  QuartzManager.modifyJobTime(request.processName, cron, JobEnum.jobIdClassMap(jobInfo.jobId()))      case _ =>  QuartzManager.removeJob(request.processName)    }    ServiceResponse("200","success")  }}

４下面就是统一对定时任务启动时重启，就可以统一重启，不需要单独添加代码启动：

import com.today.api.financetask.scala.enums.TScheduledTaskIsStartEnumimport com.today.api.financetask.scala.request.QueryAutoConfigRequestimport com.today.service.financetask.job._import com.today.service.financetask.job.define.JobEnumimport com.today.service.financetask.query.sql.{AutoConfigQuerySql, ScheduledTaskQuerySql}import com.today.service.financetask.util.QuartzManagerimport com.today.service.financetask.utils.JobInfoimport org.slf4j.LoggerFactoryimport org.springframework.context.ApplicationListenerimport org.springframework.context.event.ContextRefreshedEventimport org.springframework.stereotype.Service/**  *  类功能描述: 定时器监听器, 服务启动时启动定时器  *  * @author BarryWang create at 2018/5/11 12:04  * @version 0.0.1  */@Serviceclass ScheduleStartListener extends ApplicationListener[ContextRefreshedEvent] {  /** 日志 */  val logger = LoggerFactory.getLogger(getClass)  /**    * 启动加载执行定时任务    */  override def onApplicationEvent(event: ContextRefreshedEvent): Unit = {    logger.info("=======服务器重启定时任务启动start=======")    //启动服务时恢复常规定时任务    JobEnum.values.foreach(recoveryCommonJob(_))    logger.info("=======服务器重启定时任务启动end=======")  }  /**    * 恢复通用定时任务    * @param jobInfo 定时任务枚举    */  private def recoveryCommonJob(jobInfo: JobInfo)={    try {      val jobClass = JobEnum.jobIdClassMap(jobInfo.jobId)      ScheduledTaskQuerySql.queryByJobId(jobInfo.jobId) match {        case Some(x) => {          x.isStart match {            case TScheduledTaskIsStartEnum.YES.id => {              QuartzManager.addJobByCron(jobInfo.jobId, x.jobCron, jobClass)              logger.info(s"定时任务：'${jobInfo.jobName}'启动成功!")            }            case _ => logger.info(s"定时任务：'${jobInfo.jobName}'is_start标志为0，不启动")          }        }        case None => QuartzManager.addJobByCron(jobInfo.jobId, jobInfo.defaultCron(), jobClass)      }    } catch {      case e : Exception => logger.error(s"定时任务：'${jobInfo.jobName}'启动失败， 失败原因：", e)    }  }}

本部分也是对Quartz实现可配置的分布式定时任务的优化重构，可详见：

转载于:https://www.cnblogs.com/barrywxx/p/10810055.html

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