package cn.com.utils;

 import org.apache.commons.fileupload.FileItem;

 import org.apache.commons.fileupload.disk.DiskFileItemFactory;

 import org.springframework.util.FileCopyUtils;

 import org.springframework.web.multipart.MultipartFile;

 import org.springframework.web.multipart.commons.CommonsMultipartFile;

 import javax.activation.MimetypesFileTypeMap;

 import java.io.ByteArrayInputStream;

 import java.io.File;

 import java.io.InputStream;

 import java.io.OutputStream;

 public class FileToMultipartFileUtil {

     public static MultipartFile toMultipartFile(String fieldName, File file) throws Exception {

         DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();

         String contentType = new MimetypesFileTypeMap().getContentType(file);

         FileItem fileItem = diskFileItemFactory.createItem(fieldName, contentType, false, file.getName());

         try (

                 InputStream inputStream = new ByteArrayInputStream(FileCopyUtils.copyToByteArray(file));

                 OutputStream outputStream = fileItem.getOutputStream()

         ) {

             FileCopyUtils.copy(inputStream, outputStream);

         } catch (Exception e) {

             throw e;

         }

         MultipartFile multipartFile = new CommonsMultipartFile(fileItem);

         return multipartFile;

     }

     public static MultipartFile toMultipartFile(String fieldName, String fileName, byte[] fileByteArray) throws Exception {

         DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();

         String contentType = new MimetypesFileTypeMap().getContentType(fileName);

         FileItem fileItem = diskFileItemFactory.createItem(fieldName, contentType, false, fileName);

         try (

                 InputStream inputStream = new ByteArrayInputStream(fileByteArray);

                 OutputStream outputStream = fileItem.getOutputStream()

         ) {

             FileCopyUtils.copy(inputStream, outputStream);

         } catch (Exception e) {

             throw e;

         }

         MultipartFile multipartFile = new CommonsMultipartFile(fileItem);

         return multipartFile;

     }

 }