java – 从tasklet步骤添加参数到作业上下文,并在Spring Batch的
现在,我使用jobParameters来获取我的FlatFileItemReader和FlatFileItemWriter的文件名.可以测试我的批次,但我的目标是在某个目录中读取一个文件(该目录中只有这个文件),文件名可能会改变.输出文件名应该取决于输入的文件名.
因此,我想到为我的工作添加了一个新的步骤,这一步将通过搜索好的目录并查找文件来设置输出和输入文件名.我从Spring Doc和this thread从SO读了Passing Data to Future Steps,但是我不能使它工作,这些文件总是“null”. 首先,我定义了以下Tasklet public class SettingFilenamesTasklet implements Tasklet { private StepExecution stepExecution; @Override public RepeatStatus execute(StepContribution contribution,ChunkContext chunkContext) throws Exception { // TODO Search folder and set real filenames String inputFilename = "D:/TestInputFolder/dataFile.csv"; String outputFilename = "D:/TestOutputFolder/dataFile-processed.csv"; ExecutionContext stepContext = stepExecution.getExecutionContext(); stepContext.put("inputFile",inputFilename); stepContext.put("outputFile",outputFilename); return RepeatStatus.FINISHED; } @BeforeStep public void saveStepExecution(StepExecution stepExec) { stepExecution = stepExec; } } 然后,我添加了promotionListener bean @Bean public ExecutionContextPromotionListener promotionListener() { ExecutionContextPromotionListener listener = new ExecutionContextPromotionListener(); listener.setKeys(new String[]{ "inputFile","outputFile" }); return listener; } 我通过我的FlatFileItemWriter定义中的jobExecutionContext更改了jobParameters(我没有改变一行代码本身) @Bean @StepScope public FlatFileItemWriter<RedevableCRE> flatFileWriter(@Value("#{jobExecutionContext[outputFile]}") String outputFile) { FlatFileItemWriter<Employee> flatWriter = new FlatFileItemWriter<Employee>(); FileSystemResource isr; isr = new FileSystemResource(new File(outputFile)); flatWriter.setResource(isr); DelimitedLineAggregator<RedevableCRE> aggregator = new DelimitedLineAggregator<RedevableCRE>(); aggregator.setDelimiter(";"); BeanWrapperFieldExtractor<RedevableCRE> beanWrapper = new BeanWrapperFieldExtractor<RedevableCRE>(); beanWrapper.setNames(new String[]{ "id","firstName","lastName","phone","address" }); aggregator.setFieldExtractor(beanWrapper); flatWriter.setLineAggregator(aggregator); flatWriter.setEncoding("ISO-8859-1"); return flatWriter; } 我添加了我的Tasklet bean @Bean public SettingFilenamesTasklet settingFilenames() { return new SettingFilenamesTasklet(); } 我创建了一个新的步骤来添加我的工作申报 @Bean public Step stepSettings(StepBuilderFactory stepBuilderFactory,SettingFilenamesTasklet tasklet,ExecutionContextPromotionListener listener) { return stepBuilderFactory.get("stepSettings").tasklet(tasklet).listener(listener).build(); } 现在,FlatFileItemReader仍然使用jobParameters值,我想让我的FlatFileItemWriter首先工作.我收到以下错误: [...] Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.file.FlatFileItemWriter]: Factory method 'flatFileWriter' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:591) ... 87 common frames omitted Caused by: java.lang.NullPointerException: null at java.io.File.<init>(Unknown Source) at batchTest.BatchConfiguration.flatFileWriter(BatchConfiguration.java:165) at batchTest.BatchConfiguration$$EnhancerBySpringCGLIB$$5d415889.CGLIB$flatFileWriter$1(<generated>) at batchTest.BatchConfiguration$$EnhancerBySpringCGLIB$$5d415889$$FastClassBySpringCGLIB$$969a8527.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:312) at batchTest.BatchConfiguration$$EnhancerBySpringCGLIB$$5d415889.flatFileWriter(<generated>) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ... 88 common frames omitted 我试图用@JobScope替换@StepScope注释;将我的参数直接插入到jobExecutionContext(JobExecutionListener)中,而不是使用StepContext promotionListener …没有任何工作.当我尝试创建FlatFileItemWriter时,资源文件始终为空. 我失踪了什么 谢谢你的帮助. 解决方法
在tasklet中,你可以使用ChunkContext,所以你不需要@BeforeStep,你可以删除它(在我的配置中,它根本没有被调用,当你把它看作一个动作步骤并没有什么意义,但是我不会看NPE,所以猜测这部分工作).我们用两种方法之一解决了:
>你可以使用chunkContext.getStepContext()直接将tasklet中的任何参数添加到作业ExecutionContext中.getStepExecution().getJobExecution().getExecutionContext().put(“inputFile”,inputFilename);>您可以将ExecutionContextPromotionListener添加到tasklet步骤,然后执行chunkContext.getStepContext().getStepExecution().getExecutionContext().put(“inputFile”,inputFilename); (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |