File转MultipartFile
try {
File file = new File("H:/file/1.txt");
InputStream inputStream = new FileInputStream(file);
MultipartFile multipartFile = new MockMultipartFile(file.getName(), file.getName(), ContentType.APPLICATION_OCTET_STREAM.toString(), inputStream);
String content = new String(multipartFile.getBytes());
logger.info("content:{}", content);
} catch (IOException e) {
logger.error("error:", e);
}