Question

我正在从我的控制器启动一个弹簧批处理作业。我需要通过基于java的配置从配置的自定义fileName访问作业参数ItemReader。但是我总是从我的ItemReader获取fileName为null。请帮忙。我这样启动是因为我必须根据用户请求更改ItemReader文件。

我的控制器：

@RestController
@RequestMapping(value = "/")
public class SimpleController {


@Autowired
Step step;

@Autowired
private JobBuilderFactory jobs;

@Autowired
private StepBuilderFactory steps;

@Autowired
private JobRepository jobRepository;

@Autowired
JobLauncher jobLauncher;

@RequestMapping(method = RequestMethod.GET)
public void StartJob() throws JobParametersInvalidException, JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException {
    JobParameter param = new JobParameter("ValueBeingSetFromRequestHeader");
    HashMap map = new HashMap<String, JobParameter>();
    map.put("fileName",param);
    SimpleJob job = new SimpleJob("test");
    job.addStep(step);
    System.out.println(jobRepository);
    job.setJobRepository(jobRepository);

    System.out.println( jobRepository.getLastJobExecution(job.getName(), new JobParameters(map)));

    jobLauncher.run(job, new JobParameters(map));

}

}

我的Job步骤配置类是

public class ProducerBatchJobConfigurer {


private String fileName;

public String getFileName() {
    return fileName;
}
@Value("#{jobParameters['fileName']}")
public void setFileName(String fileName) {
    this.fileName = fileName;
}

@Bean
public ItemReader reader() {
    System.out.println(fileName);
    if (fileName == null)
        return new DummyReader();
    FlatFileItemReader faltFileReader =  new FlatFileItemReader();

    faltFileReader.setResource(new FileSystemResource(new File(fileName)));
    faltFileReader.setResource(new FileSystemResource(new File(fileName)));
    DefaultLineMapper<KafkaMessage> lineMapper = new DefaultLineMapper<KafkaMessage>();
    lineMapper.setLineTokenizer(new DelimitedLineTokenizer());
    lineMapper.setFieldSetMapper(new CSVFieldMapper());
    faltFileReader.setLineMapper(lineMapper);
    return faltFileReader;
}

@Bean
public ItemProcessor processor() {
   return new CustomItemProcessor();

}

@Bean
public ItemWriter writer() {
    return new KafkaWriter();
}



@Bean
public Step step1(StepBuilderFactory stepBuilderFactory,
                  ItemReader reader, ItemWriter writer,
                  ItemProcessor processor) {
    System.out.println("ddddddddddddddd");
    return stepBuilderFactory.get("step1")
            .chunk(10).reader(reader)
            .processor(processor).writer(writer).build();
}
@Bean
public StepScope stepScope() {
    final StepScope stepScope = new StepScope();
    stepScope.setAutoProxy(true);
    return stepScope;
}
@Bean
public JobScope jobScope(){
    return new JobScope();
}
}

Answer 1

@Bean
public ItemReader reader() {
 ...
}

应改为

@Bean
public ItemStreamReader reader() {
 ...
}

或甚至更具体的

@Bean
public FlatFileItemReader reader() {
 ...
}

步骤定义也应改为

@Bean
public Step step1(StepBuilderFactory stepBuilderFactory,
                  ItemStreamReader reader, ItemWriter writer,
                  ItemProcessor processor) {

}

为什么这有必要？

如果itemReader实现ItemStream接口（或ItemStreamReader），Spring会将其视为此类接口。

请参阅https://docs.spring.io/spring-batch/reference/html/readersAndWriters.html#delegatePatternAndRegistering

直接连接到Step的读取器，写入器或处理器如果它实现了ItemStream或a，它将自动注册 StepListener接口。

这意味着spring将调用open，update和close方法

Spring Batch: org.springframework.batch.item.ReaderNotOpenException: Reader must be open before it can be read

处的类似问题

Answer 2

使用@Value("#{jobParameters[fileName]}")代替@Value("#{jobParameters['fileName']}")

如何在Spring启动Web应用程序中从Spring批处理作业的ItemReader类访问jobparameter

2 个答案: