xUtils下載下傳檔案時總大小傳回-1問題

xUtils下載下傳檔案時無法傳回總大小是因為Accept-Encoding頭設定問題，需要設定Accept-Encoding頭為“identity”，設定方法如下：

HttpUtils http = new HttpUtils();
((DefaultHttpClient)http.getHttpClient()).addRequestInterceptor(new HttpRequestInterceptor() {
			@Override
			public void process(org.apache.http.HttpRequest httpRequest, HttpContext httpContext) throws org.apache.http.HttpException, IOException {
				if (!httpRequest.containsHeader("Accept-Encoding")) {
					httpRequest.addHeader("Accept-Encoding", "identity");
				} else {
					httpRequest.setHeader("Accept-Encoding", " identity");
				}
			}
		});