Spring Boot RestTemplate文件上传

@ResponseBody
@RequestMapping(value = "/upload.do", method = RequestMethod.POST)
public String upload(String fileName, MultipartFile jarFile) {
    // 下面是测试代码
    System.out.println(fileName);
    String originalFilename = jarFile.getOriginalFilename();
    System.out.println(originalFilename);
    try {
        String string = new String(jarFile.getBytes(), "UTF-8");
        System.out.println(string);
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    // TODO 处理文件内容...
    return "OK";
}  

@Test
public void testUpload() throws Exception {
    String url = "http://127.0.0.1:8080/test/upload.do";
    String filePath = "C:\\Users\\MikanMu\\Desktop\\test.txt";  

    RestTemplate rest = new RestTemplate();
    FileSystemResource resource = new FileSystemResource(new File(filePath));
    MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
    param.add("jarFile", resource);
    param.add("fileName", "test.txt");  

    String string = rest.postForObject(url, param, String.class);
    System.out.println(string);
} 

String string = rest.postForObject(url, param, String.class);  
可以换成以下方式
HttpEntity<MultiValueMap<String, Object>> httpEntity = new HttpEntity<MultiValueMap<String,Object>>(param);
ResponseEntity<String> responseEntity = rest.exchange(url, HttpMethod.POST, httpEntity, String.class);
System.out.println(responseEntity.getBody());  

@PostMapping(value = "/uploadFile")
    @ResponseBody
    @ApiOperation(value = "上传附件", notes = "返回结果,SUCCESS:200,FAILED:500", httpMethod = "POST")
    public String upload(@ApiParam MultipartFile importFile) throws Exception {
        String suffix = importFile.getOriginalFilename().substring(importFile.getOriginalFilename().lastIndexOf("."));
        String showUrl = aLiYunOssService.upload(importFile.getBytes(), suffix);
        return showUrl;

    }

MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
ByteArrayResource arrayResource = new ByteArrayResource(getBytes(),"test.jpg");
 parts.add("importFile", arrayResource); 
HttpEntity<MultiValueMap<String, Object>> httpEntity2 = new HttpEntity<MultiValueMap<String,Object>>(parts);
 ResponseEntity<String> responseEntity2 = rest.exchange(url, HttpMethod.POST, httpEntity2, String.class); 
System.out.println("返回地址1==="+responseEntity2.getBody());