code: protected void generateBody() throws IOException {
          // FIXME
          if (body != null && body.getContent() != null) {
              // 重置请求头中的Content-Type
              conn.setRequestProperty("Content-Type", "text/plain");
              // LOG.info(String.format("--将content数据[%s]写入outPut中",
              // body.getContent()));
              conn.getOutputStream().write(body.getContent().getBytes());
              conn.getOutputStream().flush();
          }
      }
docs: 构建请求体
  
  @throws IOException IOException