我定义了简单的工作 . tasklet然后步骤 .
我试图在这两者之间传递filePath .
当我到达词干时,会调用阅读器并在那里将filePath保持为空 .
我错过了什么?
工作配置:
@Bean
public Job processFileJob() throws Exception {
return this.jobs.get("processFileJob").start(downloadFileStep()).next(processor()).build();//.next(pushToKafkaStep()).build();
}
public Step downloadFileStep() {
return this.steps.get("downloadFileTaskletStep").tasklet(downloadFileTasklet()).build();
}
@Bean
protected Tasklet downloadFileTasklet() {
return new DownloadFileTasklet();
}
@Bean
public Step processor() {
return stepBuilderFactory.get("processor")
.<PushItemDTO, PushItemDTO>chunk(1)
.reader(reader(OVERRIDDEN_BY_EXPRESSION))
...
.build();
}
//here filePath always null!!
@Bean
@Scope(value = "step", proxyMode = ScopedProxyMode.INTERFACES)
public ItemStreamReader<PushItemDTO> reader(@Value("#{jobParameters[filePath]}") String filePath) {
FlatFileItemReader<PushItemDTO> itemReader = new FlatFileItemReader<PushItemDTO>();
itemReader.setLineMapper(lineMapper());
itemReader.setLinesToSkip(1);
itemReader.setResource(new FileSystemResource(filePath));
return itemReader;
}
DownloadFileTasklet:
public class DownloadFileTasklet implements Tasklet, StepExecutionListener {
String filePath;
@Override
public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
filePath="someurl";
return RepeatStatus.FINISHED;
}
@Override
public void beforeStep(StepExecution stepExecution) {
}
@Override
public ExitStatus afterStep(StepExecution stepExecution) {
JobParameters jobParameters = stepExecution.getJobExecution().getJobParameters();
// jobParameters.ad
stepExecution.getExecutionContext().putString("filePath", filePath);
//Return null to leave the old value unchanged.
return null;
}
我设法直接从jobLauncher传递params,同时调用这个工作,但是当我尝试在tasklet中定义新的param并希望在下一步中有它时,我得到它为null
谢谢 .
如我所推荐,我应该使用ExecutionContextPromotionListener .
所以我添加到我的java配置中:
@Bean
public ExecutionContextPromotionListener executionContextPromotionListener()
{
ExecutionContextPromotionListener executionContextPromotionListener=new ExecutionContextPromotionListener();
executionContextPromotionListener.setKeys(new String[]{"filePath"});
return new ExecutionContextPromotionListener();
}
但是我得到例外:
Caused by: java.lang.IllegalArgumentException: The 'keys' property must be provided
我通过改变返回executionContextPromotionListener来修复它;
但是filePath仍为null .
我也尝试过这样修改我的Step声明:
*添加了executionContextPromotionListener
public Step downloadFileStep() {
return this.steps.get("downloadFileTaskletStep").tasklet(downloadFileTasklet()).listener(executionContextPromotionListener()).build();
}
在filePath param中仍为null
1 回答
向步骤的
ExecutionContext
添加值使其仅可用于该步骤 . 要使其能够访问另一个步骤,您需要将该键提升为作业的ExecutionContext
. 为此,请查看ExecutionContextPromotionListener
. 它会向作业的ExecutionContext
提升你的任何键,以便可以从其他步骤访问它们 .您可以在此处的文档中阅读有关
ExecutionContextPromotionListener
的更多信息:http://docs.spring.io/spring-batch/apidocs/org/springframework/batch/core/listener/ExecutionContextPromotionListener.html