發送POST請求，包含文件MultipartFile參數，普通字符串參數，請求頭參數

與別人對接時經常會遇到既發送文件參數又發送字符串參數的請求，此請求的核心是

文件參數的ContenType=multipart/form-data

字符串參數的ContenType=application/json

/**
     * 使用httpclint 發送文件，如果不傳輸文件，直接設置fileParams=null，
     * 如果不設置請求頭參數，直接設置headerParams=null，就可以進行普通參數的POST請求了
     *
     * @param url          請求路徑
     * @param fileParams   文件參數
     * @param otherParams  其他字符串參數
     * @param headerParams 請求頭參數
     * @return
     */
    public static String uploadFile(String url, Map<String, MultipartFile> fileParams, Map<String, String> otherParams, Map<String, String> headerParams) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String result = "";
        try {
            HttpPost httpPost = new HttpPost(url);
            //設置請求頭
            if (headerParams != null && headerParams.size() > 0) {
                for (Map.Entry<String, String> e : headerParams.entrySet()) {
                    String value = e.getValue();
                    String key = e.getKey();
                    if (StringUtils.isNotBlank(value)) {
                        httpPost.setHeader(key, value);
                    }
                }
            }
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            builder.setCharset(Charset.forName("utf-8"));
            builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);//加上此行代碼解決返回中文亂碼問題
            //    文件傳輸http請求頭(multipart/form-data)
            if (fileParams != null && fileParams.size() > 0) {
                for (Map.Entry<String, MultipartFile> e : fileParams.entrySet()) {
                    String fileParamName = e.getKey();
                    MultipartFile file = e.getValue();
                    if (file != null) {
                        String fileName = file.getOriginalFilename();
                        builder.addBinaryBody(fileParamName, file.getInputStream(), ContentType.MULTIPART_FORM_DATA, fileName);// 文件流
                    }
                }
            }
            //    字節傳輸http請求頭(application/json)
            ContentType contentType = ContentType.create("application/json", Charset.forName("UTF-8"));
            if (otherParams != null && otherParams.size() > 0) {
                for (Map.Entry<String, String> e : otherParams.entrySet()) {
                    String value = e.getValue();
                    if (StringUtils.isNotBlank(value)) {
                        builder.addTextBody(e.getKey(), value, contentType);// 類似瀏覽器表單提交，對應input的name和value
                    }
                }
            }
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);
            HttpResponse response = httpClient.execute(httpPost);// 執行提交
            HttpEntity responseEntity = response.getEntity();
            if (responseEntity != null) {
                // 將響應內容轉換為字符串
                result = EntityUtils.toString(responseEntity, Charset.forName("UTF-8"));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

上面是發送請求的核心代碼

下面是請求demo

https://gitee.com/xiaorenwu_dashije/request-demo.git