code: public static void closeIOStream(InputStream in, OutputStream out) {
          if (in != null) {
              try {
                  in.close();
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
          if (out != null) {
              try {
                  out.close();
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
      }
docs: 关闭输入输出流
  
  @param in  输入流
  @param out 输出流