code: private String uploadSliceData(UploadSliceFileRequest request, String sliceContent, String session, long offset)
  			throws AbstractCosException {
  		String url = buildUrl(request);
  		long signExpired = System.currentTimeMillis() / 1000 + this.config.getSignExpired();
  		String sign = Sign.getPeriodEffectiveSign(request.getBucketName(), request.getCosPath(), this.cred, signExpired);
  
  		HttpRequest httpRequest = new HttpRequest();
  		httpRequest.setUrl(url);
  		httpRequest.addHeader(RequestHeaderKey.Authorization, sign);
  		httpRequest.addHeader(RequestHeaderKey.USER_AGENT, this.config.getUserAgent());
  
  		httpRequest.addParam(RequestBodyKey.OP, RequestBodyValue.OP.UPLOAD_SLICE);
  		httpRequest.addParam(RequestBodyKey.FILE_CONTENT, sliceContent);
  		httpRequest.addParam(RequestBodyKey.SESSION, session);
  		httpRequest.addParam(RequestBodyKey.OFFSET, String.valueOf(offset));
  
  		return httpClient.sendHttpRequest(httpRequest);
  	}
docs: 上传分片数据
  
  @param request
  分片上传请求
  @param sliceContent
  分片内容
  @param session
  session会话值
  @param offset
  分片偏移量
  @return JSON格式的字符串, 格式为{"code":$code, "message":"$mess"}, code为0表示成功,
  其他为失败, message为success或者失败原因
  @throws AbstractCosException
  SDK定义的COS异常, 通常是输入参数有误或者环境问题(如网络不通)