BufferedImage 转MultipartFile

可以使用以下代码将 `BufferedImage` 转换为 `MultipartFile`：

import org.springframework.web.multipart.MultipartFile;
import org.springframework.mock.web.MockMultipartFile;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class ImageUtil {
    public static MultipartFile bufferedImageToMultipartFile(BufferedImage image, String fileName) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(image, "jpg", baos);
        InputStream is = new ByteArrayInputStream(baos.toByteArray());

        return new MockMultipartFile(fileName, is, "image/jpeg", fileName.getBytes());
    }
}

使用示例：

BufferedImage image = ImageIO.read(new File("test.jpg"));
MultipartFile multipartFile = ImageUtil.bufferedImageToMultipartFile(image, "test.jpg");