Spring Batch 读取后删除或存档文件 · HowToDoInJava 中文系列教程

# Spring Batch 读取后删除或存档文件 > 原文： [https://howtodoinjava.com/spring-batch/delete-archive-files-after-read/](https://howtodoinjava.com/spring-batch/delete-archive-files-after-read/) 在 Spring Batch 作业中，在读取或处理后删除平面文件的最佳方法是创建单独的`Tasklet`，并在处理结束时在作业结束时执行它。 ## 删除文件的任务这是此类`Tasklet`的示例，它将在作业结束时从`c:/temp/input/`位置删除所有 CSV 文件。 `FileDeletingTasklet.java` ```java import java.io.File; import org.springframework.batch.core.StepContribution; import org.springframework.batch.core.UnexpectedJobExecutionException; import org.springframework.batch.core.scope.context.ChunkContext; import org.springframework.batch.core.step.tasklet.Tasklet; import org.springframework.batch.repeat.RepeatStatus; import org.springframework.beans.factory.InitializingBean; import org.springframework.core.io.Resource; import org.springframework.util.Assert; public class FileDeletingTasklet implements Tasklet, InitializingBean { private Resource[] resources; public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception { for(Resource r: resources) { File file = r.getFile(); boolean deleted = file.delete(); if (!deleted) { throw new UnexpectedJobExecutionException("Could not delete file " + file.getPath()); } } return RepeatStatus.FINISHED; } public void setResources(Resource[] resources) { this.resources = resources; } public void afterPropertiesSet() throws Exception { Assert.notNull(resources, "directory must be set"); } } ``` #### 存档文件随时修改`FileDeletingTasklet`中的逻辑以将文件归档到其他位置或实现自己的归档逻辑。简单的 IO 操作 ## 如何使用`FileDeletingTasklet` 在主要步骤之后创建另一个要执行的步骤并执行`FileDeletingTasklet`。 `BatchConfig.java` ```java import org.springframework.batch.core.Job; import org.springframework.batch.core.Step; import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing; import org.springframework.batch.core.configuration.annotation.JobBuilderFactory; import org.springframework.batch.core.configuration.annotation.StepBuilderFactory; import org.springframework.batch.core.launch.support.RunIdIncrementer; import org.springframework.batch.item.file.FlatFileItemReader; import org.springframework.batch.item.file.MultiResourceItemReader; import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper; import org.springframework.batch.item.file.mapping.DefaultLineMapper; import org.springframework.batch.item.file.transform.DelimitedLineTokenizer; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.Resource; import com.howtodoinjava.demo.model.Employee; @Configuration @EnableBatchProcessing public class BatchConfig { @Autowired private JobBuilderFactory jobBuilderFactory; @Autowired private StepBuilderFactory stepBuilderFactory; @Value("file:c:/temp/input/inputData*.csv") private Resource[] inputResources; @Bean public Job readCSVFilesJob() { return jobBuilderFactory .get("readCSVFilesJob") .incrementer(new RunIdIncrementer()) .start(step1()) .next(step2()) .build(); } @Bean public Step step1() { return stepBuilderFactory.get("step1").<Employee, Employee>chunk(5) .reader(multiResourceItemReader()) .writer(writer()) .build(); } @Bean public Step step2() { FileDeletingTasklet task = new FileDeletingTasklet(); task.setResources(inputResources); return stepBuilderFactory.get("step2") .tasklet(task) .build(); } @Bean public MultiResourceItemReader<Employee> multiResourceItemReader() { MultiResourceItemReader<Employee> resourceItemReader = new MultiResourceItemReader<Employee>(); resourceItemReader.setResources(inputResources); resourceItemReader.setDelegate(reader()); return resourceItemReader; } @SuppressWarnings({ "rawtypes", "unchecked" }) @Bean public FlatFileItemReader<Employee> reader() { // Create reader instance FlatFileItemReader<Employee> reader = new FlatFileItemReader<Employee>(); // Set number of lines to skips. Use it if file has header rows. reader.setLinesToSkip(1); // Configure how each line will be parsed and mapped to different values reader.setLineMapper(new DefaultLineMapper() { { // 3 columns in each row setLineTokenizer(new DelimitedLineTokenizer() { { setNames(new String[] { "id", "firstName", "lastName" }); } }); // Set values in Employee class setFieldSetMapper(new BeanWrapperFieldSetMapper<Employee>() { { setTargetType(Employee.class); } }); } }); return reader; } @Bean public ConsoleItemWriter<Employee> writer() { return new ConsoleItemWriter<Employee>(); } } ``` 现在运行该应用程序并查看日志。 `Console` ```java 2018-07-11 12:30:00 INFO - Job: [SimpleJob: [name=readCSVFilesJob]] launched with the following parameters: [{JobID=1531292400004}] 2018-07-11 12:30:00 INFO - Executing step: [step1] Employee [id=1, firstName=Lokesh, lastName=Gupta] Employee [id=2, firstName=Amit, lastName=Mishra] Employee [id=3, firstName=Pankaj, lastName=Kumar] Employee [id=4, firstName=David, lastName=Miller] Employee [id=5, firstName=Ramesh, lastName=Gupta] Employee [id=6, firstName=Vineet, lastName=Mishra] Employee [id=7, firstName=Amit, lastName=Kumar] Employee [id=8, firstName=Dav, lastName=Miller] Employee [id=9, firstName=Vikas, lastName=Kumar] Employee [id=10, firstName=Pratek, lastName=Mishra] Employee [id=11, firstName=Brian, lastName=Kumar] Employee [id=12, firstName=David, lastName=Cena] 2018-07-11 12:30:00 INFO - Executing step: [step2] Deleted file :: c:\temp\input\inputData1.csv Deleted file :: c:\temp\input\inputData2.csv Deleted file :: c:\temp\input\inputData3.csv 2018-07-11 12:30:00 INFO - Job: [SimpleJob: [name=readCSVFilesJob]] completed with the following parameters: [{JobID=1531292400004}] and the following status: [COMPLETED] ``` 将我的问题放在评论部分。学习愉快！