jason输出以导出csv文件

Question

下面是我的代码，用于将某些字段从数据库导出到csv输出文件。

Gui可以控制以csv格式导出文件。但是，输出的csv文件为空白（标头除外）。为什么会这样？

Public class somecontroller
{


try
      {

         List<CompanyContact> companyContactList = contactService.getContacts(companyType);
         List<CompanyContactsExportDTO> companyContactsExportDTOS = createCompanyContactsExportDTO(companyContactList);
         writeCsvResponse(response,fileName,CompanyContactsExportDTO.class,companyContactsExportDTOS);
         log.info("Finished exporting contacts for " + companyType + "company Type");
      } catch(Exception e)
      {
         log.error("Error producing contacts report", e);
         //Close CSV writer so it can flush & print headers in case no rows had been printed before.
//         csvRecordWriter.close();
         //add extra row stating there was an error
         response.getWriter().println();
         response.getWriter().print(buildCsvErrorMessage());
      }
      finally
      {
         response.getWriter().close();
      }

private void writeCsvResponse(HttpServletResponse response, String csvFileName, Class annotatedPojoClass, List results) throws Exception
   {
      response.setContentType("text/csv");
      response.setHeader("Content-Disposition", String.format("attachment; filename=\"%s\"", csvFileName));
      response.setHeader("X-Content-Type-Options", "nosniff");
      response.addHeader(HttpHeaders.CACHE_CONTROL, "no-cache, no-store, max-age=0, must-revalidate");
      response.addHeader(HttpHeaders.PRAGMA, "no-cache");
      response.addHeader(HttpHeaders.EXPIRES, "0");

      CsvMapper mapper = new CsvMapper();
      CsvSchema schema = mapper.schemaFor(annotatedPojoClass).withHeader();
      mapper.writer(schema).writeValue(response.getWriter(), results);
   }


}


private List<CompanyContactsExportDTO> createCompanyContactsExportDTO(List<CompanyContact> companyContactList)
   {
      List<CompanyContactsExportDTO>  companyContactsExportDTOS = new ArrayList<>();
      for(CompanyContact cc:companyContactList)
      {
         CompanyContactsExportDTO dto = new CompanyContactsExportDTO();
         dto.setCompany(cc.getCompany().getCompanyName());
         dto.setContactType(cc.getCategory());
         dto.setEmail(cc.getParent().getEmail());
         dto.setPhone(cc.getParent().getPhone());
         dto.setInfo(cc.getInfo());
         dto.setFirstNameLastName(cc.getParent().getFirstName()+ " " +cc.getParent().getLastName());
      }

      return companyContactsExportDTOS;
   }

但导出文件为空。

Jason对象如下所示

@JsonPropertyOrder({
      "company",
      "contactType",
      "info",
      "firstNameLastName",
      "phone",
      "email"
})
public class CompanyContactsExportDTO
{
   private String company;
   private String contactType;
   private String info;
   private String firstNameLastName;
   private String phone;
   private String email;

   public CompanyContactsExportDTO()
   {
   }

   public String getCompany()
   {
      return company;
   }


   public String getContactType()
   {
      return contactType;
   }


   public String getInfo()
   {
      return info;
   }

   public String getFirstNameLastName()
   {
      return firstNameLastName;
   }


   public String getPhone()
   {
      return phone;
   }


   public String getEmail()
   {
      return email;
   }






   public void setContactType(String contactType)
   {
     this.contactType = contactType;
   }

   public void setPhone(String phone)
   {
      this.phone = phone;
   }

   public void setEmail(String email)
   {
      this.email = email;
   }

   public void setInfo(String info)
   {
      this.info = info;
   }

   public void setCompany(String companyName)
   {
      this.company = companyName;
   }

   public void setFirstNameLastName(String firstNameLastName)
   {
      this.firstNameLastName = firstNameLastName;
   }
}

并且从DB派生的对象具有以下结构

public class CompanyContact
{
   private Integer id;
   private String info;
   private boolean isActive;


   private CompanyDTO company;//this is embedded object

   private String category;

   private Contact parent;//this is another embedded object

   public CompanyContact()
   {
   }

//It has other getter and setter methods
}

请让我知道我在做什么错？

谢谢