原文： 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

  1. import java.io.File;
  3. import org.springframework.batch.core.StepContribution;
  4. import org.springframework.batch.core.UnexpectedJobExecutionException;
  5. import org.springframework.batch.core.scope.context.ChunkContext;
  6. import org.springframework.batch.core.step.tasklet.Tasklet;
  7. import org.springframework.batch.repeat.RepeatStatus;
  8. import org.springframework.beans.factory.InitializingBean;
  9. import org.springframework.core.io.Resource;
  10. import org.springframework.util.Assert;
  12. public class FileDeletingTasklet implements Tasklet, InitializingBean {
  14.     private Resource[] resources;
  16.     public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
  18.         for(Resource r: resources) {
  19.             File file = r.getFile();
  20.             boolean deleted = file.delete();
  21.             if (!deleted) {
  22.                 throw new UnexpectedJobExecutionException("Could not delete file " + file.getPath());
  23.             }
  24.         }
  25.         return RepeatStatus.FINISHED;
  26.     }
  28.     public void setResources(Resource[] resources) {
  29.         this.resources = resources;
  30.     }
  32.     public void afterPropertiesSet() throws Exception {
  33.         Assert.notNull(resources, "directory must be set");
  34.     }
  35. }

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

  1. import org.springframework.batch.core.Job;
  2. import org.springframework.batch.core.Step;
  3. import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
  4. import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
  5. import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
  6. import org.springframework.batch.core.launch.support.RunIdIncrementer;
  7. import org.springframework.batch.item.file.FlatFileItemReader;
  8. import org.springframework.batch.item.file.MultiResourceItemReader;
  9. import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
  10. import org.springframework.batch.item.file.mapping.DefaultLineMapper;
  11. import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
  12. import org.springframework.beans.factory.annotation.Autowired;
  13. import org.springframework.beans.factory.annotation.Value;
  14. import org.springframework.context.annotation.Bean;
  15. import org.springframework.context.annotation.Configuration;
  16. import org.springframework.core.io.Resource;
  18. import com.howtodoinjava.demo.model.Employee;
  20. @Configuration
  21. @EnableBatchProcessing
  22. public class BatchConfig
  23. {
  24.     @Autowired
  25.     private JobBuilderFactory jobBuilderFactory;
  27.     @Autowired
  28.     private StepBuilderFactory stepBuilderFactory;
  30.     @Value("file:c:/temp/input/inputData*.csv")
  31.     private Resource[] inputResources;
  33.     @Bean
  34.     public Job readCSVFilesJob() {
  35.         return jobBuilderFactory
  36.                 .get("readCSVFilesJob")
  37.                 .incrementer(new RunIdIncrementer())
  38.                 .start(step1())
  39.                 .next(step2())
  40.                 .build();
  41.     }
  43.     @Bean
  44.     public Step step1() {
  45.         return stepBuilderFactory.get("step1").<Employee, Employee>chunk(5)
  46.                 .reader(multiResourceItemReader())
  47.                 .writer(writer())
  48.                 .build();
  49.     }
  51.     @Bean
  52.     public Step step2() {
  53.         FileDeletingTasklet task = new FileDeletingTasklet();
  54.         task.setResources(inputResources);
  55.         return stepBuilderFactory.get("step2")
  56.                 .tasklet(task)
  57.                 .build();
  58.     }
  60.     @Bean
  61.     public MultiResourceItemReader<Employee> multiResourceItemReader()
  62.     {
  63.         MultiResourceItemReader<Employee> resourceItemReader = new MultiResourceItemReader<Employee>();
  64.         resourceItemReader.setResources(inputResources);
  65.         resourceItemReader.setDelegate(reader());
  66.         return resourceItemReader;
  67.     }
  69.     @SuppressWarnings({ "rawtypes", "unchecked" })
  70.     @Bean
  71.     public FlatFileItemReader<Employee> reader()
  72.     {
  73.         // Create reader instance
  74.         FlatFileItemReader<Employee> reader = new FlatFileItemReader<Employee>();
  75.         // Set number of lines to skips. Use it if file has header rows.
  76.         reader.setLinesToSkip(1);
  77.         // Configure how each line will be parsed and mapped to different values
  78.         reader.setLineMapper(new DefaultLineMapper() {
  79.             {
  80.                 // 3 columns in each row
  81.                 setLineTokenizer(new DelimitedLineTokenizer() {
  82.                     {
  83.                         setNames(new String[] { "id", "firstName", "lastName" });
  84.                     }
  85.                 });
  86.                 // Set values in Employee class
  87.                 setFieldSetMapper(new BeanWrapperFieldSetMapper<Employee>() {
  88.                     {
  89.                         setTargetType(Employee.class);
  90.                     }
  91.                 });
  92.             }
  93.         });
  94.         return reader;
  95.     }
  97.     @Bean
  98.     public ConsoleItemWriter<Employee> writer()
  99.     {
  100.         return new ConsoleItemWriter<Employee>();
  101.     }
  102. }

现在运行该应用程序并查看日志。

Console

  1. 2018-07-11 12:30:00 INFO  - Job: [SimpleJob: [name=readCSVFilesJob]] launched with the following parameters: [{JobID=1531292400004}]
  3. 2018-07-11 12:30:00 INFO  - Executing step: [step1]
  5. Employee [id=1, firstName=Lokesh, lastName=Gupta]
  6. Employee [id=2, firstName=Amit, lastName=Mishra]
  7. Employee [id=3, firstName=Pankaj, lastName=Kumar]
  8. Employee [id=4, firstName=David, lastName=Miller]
  9. Employee [id=5, firstName=Ramesh, lastName=Gupta]
  10. Employee [id=6, firstName=Vineet, lastName=Mishra]
  11. Employee [id=7, firstName=Amit, lastName=Kumar]
  12. Employee [id=8, firstName=Dav, lastName=Miller]
  13. Employee [id=9, firstName=Vikas, lastName=Kumar]
  14. Employee [id=10, firstName=Pratek, lastName=Mishra]
  15. Employee [id=11, firstName=Brian, lastName=Kumar]
  16. Employee [id=12, firstName=David, lastName=Cena]
  18. 2018-07-11 12:30:00 INFO  - Executing step: [step2]
  20. Deleted file :: c:\temp\input\inputData1.csv
  21. Deleted file :: c:\temp\input\inputData2.csv
  22. Deleted file :: c:\temp\input\inputData3.csv
  24. 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！