如何使用 spring-batch 和 MultiResourceItemReader 读取文件夹中的所有文件?

How to read all files in a folder with spring-batch and MultiResourceItemReader?

我想配置 spring-batch 以按顺序读取特定文件夹中的所有 csv 文件。

以下内容不起作用,因为代表将尝试打开名为 *.csv 的文件,这当然是无效的。我必须在这里更改什么?

    @Bean
    public ItemReader<String> reader() {
        MultiResourceItemReader<String> reader = new MultiResourceItemReader<>();
        reader.setResources(new Resource[] {new FileSystemResource("/myfolder/*.csv")});
        reader.setDelegate(new FlatFileItemReader<>(..));
        return reader;
}

等价的xml配置应该写成下面这样,怎么改写成java only config?

<bean id="reader" class="org.springframework.batch.item.file.MultiResourceItemReader">
        <property name="resources" value="/mypfolder/*.csv"/>
        <property name="delegate" ref="flatFileItemReader"/>
</bean>

我认为你应该使用 PathMatchingResourcePatternResolver

像这样使用 PathMatchingResourcePatternResolver。

@Bean
public ItemReader<String> reader() {
    Resource[] resources = null;
    ResourcePatternResolver patternResolver = new PathMatchingResourcePatternResolver();   
    try {
        resources = patternResolver.getResources("/myfolder/*.csv");
    } catch (IOException e) {
        e.printStackTrace();
    }
    MultiResourceItemReader<String> reader = new MultiResourceItemReader<>();
    reader.setResources(resources);
    reader.setDelegate(new FlatFileItemReader<>(..));
    return reader;
}

绝对文件路径读取多个文件:

 @Bean
      public MultiResourceItemReader<POJO> multiResourceItemReader() {
        MultiResourceItemReader<POJO> resourceItemReader = new MultiResourceItemReader<POJO>();
            ClassLoader cl = this.getClass().getClassLoader();
            ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(cl);

        Resource[] resources = resolver.getResources("file:" + filePath );
        resourceItemReader.setResources(resources);
        resourceItemReader.setDelegate(reader());
        return resourceItemReader;
      }

      @Bean
      public FlatFileItemReader<POJO> reader() {
        FlatFileItemReader<POJO> reader = new FlatFileItemReader<POJO>();
        reader.setLineMapper(new DefaultLineMapper() {{
          setLineTokenizer(new DelimitedLineTokenizer() {{
            setNames(new String[]{"id1", "POJO"});
          }});
          setFieldSetMapper(new BeanWrapperFieldSetMapper<POJO>() {{
            setTargetType(POJO.class);
          }});
        }});
        return reader;
      }

或者可以使用@Value 注解让 ResourceArrayPropertyEditor 将字符串转换为 Resource[]。

@Bean
@StepScope
public ItemReader<String> reader(
        @Value("file:/myfolder/*.csv") Resource[] resources
) {
    MultiResourceItemReader<String> reader = new MultiResourceItemReader<>();
    reader.setResources(resources);
    reader.setDelegate(new FlatFileItemReader<>(..));
    return reader;
}