spingboot解析CSV文件

1. 导入opencsv库：将opencsv库添加到项目的依赖中。

   <dependency>
       <groupId>com.opencsv</groupId>
       <artifactId>opencsv</artifactId>
       <version>5.3</version>
   </dependency>
   

2. 创建MappingStrategy对象：创建一个实现MappingStrategy接口的Java类来描述CSV文件中的数据格式，并创建MappingStrategy对象。

   Name,Email,Phone
   John Doe,[email protected],123-456-7890
   Jane Doe,[email protected],987-654-3210
   

   那么可以创建一个Person类来描述CSV文件中的每一行数据，并实现MappingStrategy接口来将CSV文件中的每一行数据映射到Person对象中。

   public class Person {
       private String name;
       private String email;
       private String phone;
   
       // getters and setters
   }
   
   public class PersonMappingStrategy extends HeaderColumnNameMappingStrategy<Person> {
       @Override
       public Person createBean() throws InstantiationException, IllegalAccessException {
           return new Person();
       }
   }
   

3. 在Spring Boot的配置类中配置MultipartResolver：在Spring Boot应用程序的配置类中，配置MultipartResolver来处理MultipartFile上传的文件。

   import org.springframework.context.annotation.Bean;
   import org.springframework.context.annotation.Configuration;
   import org.springframework.web.multipart.commons.CommonsMultipartResolver;
   
   @Configuration
   public class AppConfig {
       @Bean
       public CommonsMultipartResolver multipartResolver() {
           CommonsMultipartResolver resolver = new CommonsMultipartResolver();
           resolver.setDefaultEncoding("utf-8");
           resolver.setMaxUploadSize(1024 * 1024 * 10); // 设置上传文件的最大大小为10MB
           return resolver;
       }
   }
   

4. 创建Controller类来处理上传文件：创建一个Controller类，使用@RequestBody注解将上传的MultipartFile对象转换为File对象，然后使用CsvToBeanBuilder将文件中的数据映射到Java对象中。

   import com.opencsv.bean.CsvToBean;
   import com.opencsv.bean.CsvToBeanBuilder;
   import org.springframework.stereotype.Controller;
   import org.springframework.web.bind.annotation.PostMapping;
   import org.springframework.web.bind.annotation.RequestBody;
   import org.springframework.web.multipart.MultipartFile;
   
   import java.io.BufferedReader;
   import java.io.File;
   import java.io.IOException;
   import java.io.InputStreamReader;
   import java.util.List;
   
   @Controller
   public class FileUploadController {
   
       @PostMapping("/upload")
       public String uploadFile(@RequestBody MultipartFile file) throws IOException {
           // 将MultipartFile对象转换为File对象
           File csvFile = File.createTempFile("temp", ".csv");
           file.transferTo(csvFile);
   
           // 创建MappingStrategy对象和CsvToBean对象
           MappingStrategy<Person> strategy = new PersonMappingStrategy();
           CsvToBean<Person> csvToBean = new CsvToBeanBuilder<Person>(new BufferedReader(new InputStreamReader(file.getInputStream())))
                   .withMappingStrategy(strategy)
                   .withType(Person.class)
                   .build();
   
           // 读取CSV文件数据
           List<Person> personList = csvToBean.parse();
   
           // Do something with personList
   
           return "redirect:/";
       }
   }