Spring Batch Item Reader仅执行一次 [英] Spring Batch Item Reader is executing only once

问题描述

尝试实现Spring批处理，但遇到一个奇怪的问题，我们的ItemReader类仅执行一次.

Trying to implement Spring batch,but facing a strange problem,Our ItemReader class is executing only once.

下面是详细信息.

1. 如果数据库中有1000行.
2. 我们的项目读取器从数据库中获取1000行，并将列表传递给ItemWriter
3. ItemWriter成功删除所有项目.
4. 现在ItemReader再次尝试从DB读取数据，但是没有找到，因此返回NULL，因此执行停止.
5. 但是我们已将批处理配置为使用Quartz调度程序执行，这是每分钟一次.
6. 现在，如果我们通过转储导入在数据库中插入1000行，那么批处理作业应在下次执行时选择该数据，但即使执行，它也不会执行 JobLauncher正在执行.

1. If we have 1000 rows in DB.
2. Our Item reader fetch 1000 rows from DB,and pass list to ItemWriter
3. ItemWriter successfully delete all items.
4. Now ItemReader again tries to fetch the data from DB,but did not find,hence returns NULL,so execution stops.
5. But we have configured batch to be executed with Quartz scheduler,which is every minute.
6. Now if we insert let say 1000 rows in DB by dump import,the batch job should pick this data in next execution,but it is not even executing,although JobLauncher is executing.

配置:-

1.我们有ItemReader，ItemWriter，提交间隔等于1.

1.We have ItemReader,ItemWriter with commit interval equals to 1.

<batch:job id="csrfTokenBatchJob">
    <batch:step id="step1">
      <tasklet>
        <chunk reader="csrfTokenReader" writer="csrfTokenWriter" commit-interval="1"></chunk>
      </tasklet>
    </batch:step>
  </batch:job>

2.Job计划每分钟触发一次.

2.Job is scheduled to be triggered at every minute.

<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
    <property name="triggers">
      <bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
        <property name="jobDetail" ref="jobDetail" />
        <property name="cronExpression" value="0 0/1 * * * ?" />
      </bean>
    </property>
  </bean>

3.作业配置

<bean id="jobDetail" class="org.springframework.scheduling.quartz.JobDetailBean">
    <property name="jobClass" value="com.tavant.oauth.batch.job.CSRFTokenJobLauncher" />
    <property name="jobDataAsMap">
        <map>
            <entry key="jobName" value="csrfTokenCleanUpBatchJob" />
            <entry key="jobLocator" value-ref="jobRegistry" />
            <entry key="jobLauncher" value-ref="jobLauncher" />
        </map>
    </property>
</bean>

第一次成功执行，但是后来不执行，但是我可以在日志中看到JobLauncher正在执行.

First time it is executing successfully,but later it does not execute,but i can see in logs that JobLauncher is executing.

@Component("csrfTokenReader")
@Scope(value="step")
public class CSRFTokenReader implements ItemReader<List<CSRFToken>> {

    private static final Logger logger = LoggerFactory.getLogger(CSRFTokenReader.class);

    @Autowired
    private CleanService cleanService;

    @Override
    public List<CSRFToken> read() {
        List<CSRFToken> csrfTokenList = null;
        try{

            int keepUpto = Integer.valueOf(PropertiesContext.getInstance().getProperties().getProperty("token.keep", "1"));

            Calendar calTime = Calendar.getInstance();
            calTime.add(Calendar.HOUR, -keepUpto);
            Date toKeep = calTime.getTime();

            csrfTokenList = cleanService.getCSRFTokenByTime(toKeep);
        }
        catch(Throwable th){
            logger.error("Exception in running job At " + new Date() + th);
        }
        if(CollectionUtils.isEmpty(csrfTokenList)){
            return null;
        }
        return csrfTokenList;
    }
}

-

public class CSRFTokenJobLauncher extends QuartzJobBean {
    static final String JOB_NAME = "jobName";
    private JobLocator jobLocator;
    private JobLauncher jobLauncher;
    public void setJobLocator(JobLocator jobLocator) {
        this.jobLocator = jobLocator;
    }
    public void setJobLauncher(JobLauncher jobLauncher) {
        this.jobLauncher = jobLauncher;
    }
    @Override
    protected void executeInternal(JobExecutionContext context) {
        Map<String, Object> jobDataMap = context.getMergedJobDataMap();
        String jobName = (String) jobDataMap.get(JOB_NAME);
        log.info("Quartz trigger firing with Spring Batch jobName="+jobName);
        JobParameters jobParameters = getJobParametersFromJobMap(jobDataMap);
        try {
            jobLauncher.run(jobLocator.getJob(jobName), jobParameters);
        }
        catch (JobExecutionException e) {
            log.error("Could not execute job.", e);
        }
    }
    private JobParameters getJobParametersFromJobMap(Map<String, Object> jobDataMap) {
        JobParametersBuilder builder = new JobParametersBuilder();
        for (Entry<String, Object> entry : jobDataMap.entrySet()) {
            String key = entry.getKey();
            Object value = entry.getValue();
            if (value instanceof String && !key.equals(JOB_NAME)) {
                builder.addString(key, (String) value);
            }
            else if (value instanceof Float || value instanceof Double) {
                builder.addDouble(key, ((Number) value).doubleValue());
            }
            else if (value instanceof Integer || value instanceof Long) {
                builder.addLong(key, ((Number)value).longValue());
            }
            else if (value instanceof Date) {
                builder.addDate(key, (Date) value);
            }
        }
        return builder.toJobParameters();
    }
}

推荐答案

经过数小时的浪费，现在看来问题已经解决了，我已在tasklet中配置了allow-start-if-complete="true".现在，批处理项目读取器正在按计划执行.

After hours of time wasting,the problem seems to be solved now,i have configured allow-start-if-complete="true" in tasklet.Now Batch Item Reader is executing as per schedule.

<batch:job id="csrfTokenBatchJob">
    <batch:step id="step1">
      <batch:tasklet allow-start-if-complete="true">
        <batch:chunk reader="csrfTokenReader" writer="csrfTokenWriter" commit-interval="1"></batch:chunk>
      </batch:tasklet>
    </batch:step>
  </batch:job>

这篇关于Spring Batch Item Reader仅执行一次的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！