code: public static TranslatecontentResult translatecontent(String accessToken, String lfrom, String lto, String content) {
          HttpPost httpPost = new HttpPost(BASE_URI + "/cgi-bin/media/voice/translatecontent");
          byte[] data;
          try {
              data = content.getBytes("UTF-8");
          } catch (IOException e) {
              logger.error("", e);
              throw new RuntimeException(e);
          }
  
          HttpEntity reqEntity = MultipartEntityBuilder.create()
                  .addBinaryBody("media", data, ContentType.DEFAULT_BINARY, "temp.txt")
                  .addTextBody(PARAM_ACCESS_TOKEN, API.accessToken(accessToken))
                  .addTextBody("lfrom", lfrom)
                  .addTextBody("lto", lto)
                  .build();
          httpPost.setEntity(reqEntity);
  
          return LocalHttpClient.executeJsonResult(httpPost, TranslatecontentResult.class);
      }
docs: 微信翻译
  
  @param accessToken 接口调用凭证
  @param lfrom       源语言，zh_CN 或 en_US
  @param lto         目标语言，zh_CN 或 en_US
  @param content     源内容放body里或者上传文件的形式（utf8格式，最大600Byte)
  @return TranslatecontentResult
  @since 2.8.22