Question

我想实现重新启动作业的功能，以从初始鼠尾草启动它。我面临两个问题。

第一个问题：当我第一次重新启动作业时，它将创建一个新的作业实例ID，并表现得像一个新的作业。第二次，它将重新启动并以相同的作业实例ID运行。（我从rest控制器发送了执行ID）

第二个问题：它将在我重新启动时从初始阶段开始。

自定义阅读器：

package com.orange.alc.dabekdataload.reader;

    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.batch.core.StepExecution;
    import org.springframework.batch.core.annotation.AfterStep;
    import org.springframework.batch.core.annotation.BeforeStep;
    import org.springframework.batch.item.ExecutionContext;
    import org.springframework.batch.item.ItemReader;
    import org.springframework.batch.item.ItemStream;
    import org.springframework.batch.item.ItemStreamException;
    import org.springframework.batch.item.NonTransientResourceException;
    import org.springframework.batch.item.ParseException;
    import org.springframework.batch.item.UnexpectedInputException;
    import org.springframework.batch.item.file.FlatFileItemReader;
    import org.springframework.batch.item.file.mapping.DefaultLineMapper;
    import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Scope;
    import org.springframework.context.annotation.ScopedProxyMode;
    import org.springframework.core.io.FileSystemResource;
    import org.springframework.stereotype.Component;

    import com.orange.alc.dabekdataload.constants.PostalHeader;
    import com.orange.alc.dabekdataload.dto.PostalDto;

    @Component("itemReader")
    @Scope(value = "step", proxyMode = ScopedProxyMode.TARGET_CLASS)
    public class PostalReader implements ItemReader<PostalDto>, ItemStream{

        private static final Logger LOGGER = LoggerFactory.getLogger(PostalReader.class);

        @Value("#{jobParameters[fullPathFileName]}")
        public String fileName;

        private int currentIndex = 0;

        private static final String CURRENT_INDEX = "current.index";

        private FlatFileItemReader<PostalDto> reader;

        @BeforeStep
        public void beforeStep(StepExecution stepExecution) {
            LOGGER.info("Executing batch reader...");
            reader = new FlatFileItemReader<>();
            reader.setResource(new FileSystemResource(fileName));
            reader.setLinesToSkip(1);
            reader.setLineMapper(new DefaultLineMapper<PostalDto>() {{
                setLineTokenizer(new DelimitedLineTokenizer() {{
                    setNames(PostalHeader.getPostalColumnNames());
                }});
                setFieldSetMapper(new PostalFieldSetMapper());
            }});
            reader.setSaveState(true);
            reader.open(stepExecution.getExecutionContext());

        }

        @Override
        public PostalDto read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
            reader.setCurrentItemCount(currentIndex++);
           return reader.read();
        }

        @AfterStep
        public void afterStep(StepExecution stepExecution) {
            LOGGER.info("Closing the reader...");
            reader.close();
        }

        @Override
        public void open(ExecutionContext executionContext) throws ItemStreamException {
            if(executionContext.containsKey(CURRENT_INDEX)){
                currentIndex = new Long(executionContext.getLong(CURRENT_INDEX)).intValue();
            } else{
                currentIndex = 0;
            }

        }

        @Override
        public void update(ExecutionContext executionContext) throws ItemStreamException {
            executionContext.putLong(CURRENT_INDEX, new Long(currentIndex).longValue());

        }

        @Override
        public void close() throws ItemStreamException {


        }


    }

作业重启代码：

@Override
public void restartJob(Long jobId) throws JobInstanceAlreadyCompleteException, NoSuchJobExecutionException, NoSuchJobException, JobRestartException, JobParametersInvalidException {
    LOGGER.info("Restarting job with JobId: {}", jobId);
    jobOperator.restart(jobId);
}

如果您需要我身边的任何代码，请告诉我。

Answer 1

自定义阅读器（FlatFileItemReader）中使用的委托阅读器（PostalReader）没有遵守ItemStream合同。您需要使用项目阅读器的相应open/update/close方法在委托阅读器上调用open/update/close。像这样：

public class PostalReader implements ItemReader<PostalDto>, ItemStream{

   private FlatFileItemReader<PostalDto> reader;

   @Override
   public void open(ExecutionContext executionContext) throws ItemStreamException {
      reader.open(executionContext);
   }

   @Override
   public void update(ExecutionContext executionContext) throws ItemStreamException {
      reader.update(executionContext);
   }

   @Override
   public void close() throws ItemStreamException {
      reader.close();
   }
}

Answer 2

itemStream的更新方法会将exeuctionContext置于当前Step的执行上下文中。但是，当您重新启动作业时，该步骤将作为新步骤重新运行，并且无法获取上一步的执行上下文。为了从剩余位置开始处理数据，您需要将状态保存在作业执行上下文中。

spring批处理重新启动作业从初始阶段开始，而不是从哪里停止？

2 个答案: