InputStream转MultipartFile

原文：https://blog.csdn.net/niugang0920/article/details/109337641

    //调用放
    MultipartFile multipartFile = getMultipartFile(inputStream, originalFilename);

 /**
     * 获取封装得MultipartFile
     *
     * @param inputStream inputStream
     * @param fileName    fileName
     * @return MultipartFile
     */
    public MultipartFile getMultipartFile(InputStream inputStream, String fileName) {
        FileItem fileItem = createFileItem(inputStream, fileName);
        //CommonsMultipartFile是feign对multipartFile的封装，但是要FileItem类对象
        return new CommonsMultipartFile(fileItem);
    }


    /**
     * FileItem类对象创建
     *
     * @param inputStream inputStream
     * @param fileName    fileName
     * @return FileItem
     */
    public FileItem createFileItem(InputStream inputStream, String fileName) {
        FileItemFactory factory = new DiskFileItemFactory(16, null);
        String textFieldName = "file";
        FileItem item = factory.createItem(textFieldName, MediaType.MULTIPART_FORM_DATA_VALUE, true, fileName);
        int bytesRead = 0;
        byte[] buffer = new byte[8192];
        OutputStream os = null;
        //使用输出流输出输入流的字节
        try {
            os = item.getOutputStream();
            while ((bytesRead = inputStream.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            inputStream.close();
        } catch (IOException e) {
            log.error("Stream copy exception", e);
            throw new IllegalArgumentException("文件上传失败");
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    log.error("Stream close exception", e);

                }
            }
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    log.error("Stream close exception", e);
                }
            }
        }

        return item;
    }