Question

我有一个包含成千上万个带有JSON内容的文本文件的文件夹，我需要读取这些文件，将其转换为POJO，然后保存至MySQL数据库。

我打算使用springboot批处理应用程序。到目前为止，这是一个问题，我所做的研究仅显示读取多个csv文件或xml文件，而没有json数据。具体来说，我需要将此方法转换为将csv文件解析为json解析器

@Bean
Public FlatFileItemReader<Person> reader(){
FlatFileItemReader<Person> reader=new  FlatFileItemReader<Person> reader();
reader.setLineMapper(new DefaultLineMapper<Person>(){{
setLineTokenizer(new DeLimitedLineTokenizer(){{
setNames(new String[] {"firstname","lastname","email","age"});
 }});
setFieldSetMapper(new BeanWrapperFieldSetMapper<Person> {{
setTargetType(Person.class);
}});
return reader;
}

此代码解析一个json文件

 JSONParser parser = new JSONParser();

Object object = parser.parse(new FileReader("c:\\directory path\\sample.txt"));
Person person=(Person)object;

该方法可能类似于

@Bean
Public FileReader<Person> reader(){
   FileReader<Person> reader=new FileReader<Person>();

/****need help on what to do here**/
 return reader;
  }

还看到我正在读取目录中的所有文件，我正在以这种格式传递该目录的值

@Value(value="C:\\Users\\user\\Documents\\json_dump\NW_*.txt")
private Resource[] resources;

所以我需要有关如何使用此值（所有文件的目录）而不是我先前显示的内容（单个文件位置）的帮助

Object object = parser.parse(new FileReader("c:\\directory path\\sample.txt"));

Answer 1

You can use the MultiResourceItemReader with a JsonItemReader as delegate. Here is a quick example:

@Bean
public JsonItemReader<Person> jsonItemReader(Resources[] resources) {
   JsonItemReader<Person> delegate = new JsonItemReaderBuilder<Person>()
      .jsonObjectReader(new JacksonJsonObjectReader<>(Person.class))
      .name("personItemReader")
      .build();

   MultiResourceItemReader<Person> reader = new MultiResourceItemReader<Person>();
   reader.setDelegate(delegate);
   reader.setResources(resources);
   return reader;
}

You can find more details about the JsonItemReader in the reference documentation.

Hope this helps.

Answer 2

https://docs.spring.io/spring-batch/4.0.x/reference/html/readersAndWriters.html#multiFileInput-我只有在找到答案后才找到

读取多个Json文件并转换为POJO Springboot批处理

2 个答案: