一、业务需求：

需要请求第三方接口上传文件，该请求类型是form-data请求

二、postmant请求结果如下

三、maven依赖：

        
        
            org.apache.httpcomponents
            httpcore
            4.4.9
        
        
            org.apache.httpcomponents
            httpclient
            4.5.13
        
        
            org.apache.httpcomponents
            httpmime
            4.5.12
        

四、java实现请求

    public static void test() {
        String goodsUrl = "http://0.0.0.0:7000/pangu/";
        //本地文件位置
        String fileName = "D:\\222.png";
        String str = null;
        try {
            //添加请求头
            HashMap map = new HashMap<>();
            //map.put("token", CommonConstant.token);
            File file = new File(fileName);
            str = doPostUploadFile(goodsUrl + "/sacw/CommonConfig/uploadFile", map, file);
            if(file.exists()) {
                //boolean delete = file.delete();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * post请求提交form-data上传文件
     *
     * @param url 上传地址
     * @param headers 请求头
     * @param file 上传文件
     * @return
     */
    public static String doPostUploadFile(String url, Map headers, File file) {
        HttpPost httpPost = new HttpPost(url);
        packageHeader(headers, httpPost);
        String fileName = file.getName();
        CloseableHttpResponse response = null;
        String respContent = null;
        long startTime = System.currentTimeMillis();
        // 设置请求头 boundary边界不可重复，重复会导致提交失败
        String boundary = "-------------------------" + UUID.randomUUID().toString();
        httpPost.setHeader("Content-Type", "multipart/form-data; boundary=" + boundary);
        // 创建MultipartEntityBuilder
        MultipartEntityBuilder builder = MultipartEntityBuilder.create();
        // 设置字符编码
        builder.setCharset(StandardCharsets.UTF_8);
        // 模拟浏览器
        builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
        // 设置边界
        builder.setBoundary(boundary);
        // 设置multipart/form-data流文件
        builder.addPart("sendfile", new FileBody(file));
        builder.addTextBody("fileType", "1");
        // application/octet-stream代表不知道是什么格式的文件
        builder.addBinaryBody("media", file, ContentType.create("application/octet-stream"), fileName);
        HttpEntity entity = builder.build();
        httpPost.setEntity(entity);
        CloseableHttpClient httpClient = HttpClients.createDefault();
        try {
            response = httpClient.execute(httpPost);
            if (response != null && response.getStatusLine() != null && response.getStatusLine().getStatusCode() < 400) {
                HttpEntity he = response.getEntity();
                if (he != null) {
                    respContent = EntityUtils.toString(he, "UTF-8");
                }
            } else {
                logger.error("对方响应的状态码不在符合的范围内!");
                throw new RuntimeException();
            }
            return respContent;
        } catch (Exception e) {
            logger.error("网络访问异常,请求url地址={},响应体={},error={}", url, response, e);
            throw new RuntimeException();
        } finally {
            logger.info("统一外网请求参数打印,post请求url地址={},响应={},耗时={}毫秒", url, respContent, (System.currentTimeMillis() - startTime));
            try {
                if (response != null) {
                    response.close();
                }
                if(null != httpClient){
                    httpClient.close();
                }
            } catch (IOException e) {
                logger.error("请求链接释放异常", e);
            }
        }
    }
    /**
     * 封装请求头
     *
     * @param paramsHeads
     * @param httpMethod
     */
    private static void packageHeader(Map paramsHeads, HttpRequestBase httpMethod) {
        if (null!= paramsHeads && paramsHeads.size()>0) {
            Set> entrySet = paramsHeads.entrySet();
            for (Map.Entry entry : entrySet) {
                httpMethod.setHeader(entry.getKey(), entry.getValue());
            }
        }
    }

 注意：这里的builder.addPart("sendfile", new FileBody(file));，multipartFile对应form表单的字段名称。

参考：Java发送form-data请求实现文件上传_IceFloe_Rot的博客-CSDN博客