RestTemplate如何实现文件上传呢?

RestTemplate上传示例1

public String uploadFile(File file) {
    // 1.封装请求头
    HttpHeaders headers = new HttpHeaders();
    MediaType type = MediaType.parseMediaType("multipart/form-data");
    headers.setContentType(type);
    headers.setContentLength(file.length());
    headers.setContentDispositionFormData("media", file.getName());
    // 2.封装请求体
    MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
    FileSystemResource resource = new FileSystemResource(file);
    param.add("file", resource);
    // 3.封装整个请求报文
    HttpEntity<MultiValueMap<String, Object>> formEntity = new HttpEntity<>(param, headers);
    // 4.发送请求
    ResponseEntity<String> data = restTemplate.postForEntity(tempMaterialUploadUrl, formEntity, String.class);
    // 5.请求结果处理
    JSONObject weChatResult = JSONObject.parseObject(data.getBody());
    return weChatResult;
}

上传文件InputStream流

public String uploadInputStream(InputStream inputStream,String fileName,long cententLength) {
    // 1、封装请求头
    HttpHeaders headers = new HttpHeaders();
    MediaType type = MediaType.parseMediaType("multipart/form-data");
    headers.setContentType(type);
    headers.setContentDispositionFormData("media", fileName);
    // 2、封装请求体
    MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
    InputStreamResource resource = new InputStreamResource(inputStream){
        @Override
        public long contentLength(){
            return cententLength;
        }
        @Override
        public String getFilename(){
            return fileName;
        }
    };
    param.add("file", resource);
    // 3、封装整个请求报文
    HttpEntity<MultiValueMap<String, Object>> formEntity = new HttpEntity<>(param, headers);
    // 4、发送请求
    ResponseEntity<String> data = restTemplate.postForEntity(tempMaterialUploadUrl, formEntity, String.class);
    // 5、请求结果处理
    JSONObject weChatResult = JSONObject.parseObject(data.getBody());
    // 6、返回结果
    return weChatResult;
}

上传MultipartFile类型文件

 
public String uploadFileWithInputStream(MultipartFile file) throws IOException {
    // 1、封装请求头
    HttpHeaders headers = new HttpHeaders();
    MediaType type = MediaType.parseMediaType("multipart/form-data");
    headers.setContentType(type);
    headers.setContentLength(file.getSize());
    headers.setContentDispositionFormData("media", file.getOriginalFilename());
    // 2、封装请求体
    MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
    // 将multipartFile转换成byte资源进行传输
    ByteArrayResource resource = new ByteArrayResource(file.getBytes()) {
        @Override
        public String getFilename() {
            return file.getOriginalFilename();
        }
    };
    param.add("file", resource);
    // 3、封装整个请求报文
    HttpEntity<MultiValueMap<String, Object>> formEntity = new HttpEntity<>(param, headers);
    // 4、发送请求
    ResponseEntity<String> data = restTemplate.postForEntity(tempMaterialUploadUrl, formEntity, String.class);
    // 5、请求结果处理
    JSONObject weChatResult = JSONObject.parseObject(data.getBody());
    // 6、返回结果
    return weChatResult;
}