安卓客户端从阿里云下载文件经常出错

安卓客户端从阿里云下载文件，请求到的文件长度跟实际长度经常是不相符的，每次要重复下载很多次才能下载成功，常见的错误长度19040175,5801825，急急急！！
代码如下：

请求错误是返回的请求头信息：
{null=[HTTP/1.1 200 OK],
Accept-Ranges=[bytes],
Connection=[keep-alive],
Content-Length=[19040175],
Content-Type=[application/octet-stream],
Date=[Fri, 21 Oct 2016 11:58:10 GMT],
ETag=["5743f335-12287af"],
Last-Modified=[Tue, 24 May 2016 06:22:45 GMT],
Server=[openresty/1.7.2.1],
X-Android-Received-Millis=[1477051415195],
X-Android-Response-Source=[NETWORK 200],
X-Android-Selected-Protocol=[http/1.1],
X-Android-Sent-Millis=[1477051415170]}
请求正确是返回的请求头信息：
{null=[HTTP/1.1 200 OK],
Accept-Ranges=[bytes],
Cache-Control=[No-Cache],
Connection=[keep-alive],
Content-Disposition=[attachment;
filename=E1AD5F8F9D75346DEC7F4B8A0B50DFE0.apk],
Content-Length=[77092184],
Content-MD5=[4a1fj511NG3sf0uKC1Df4A==],
Content-Type=[application/octet-stream],
Date=[Fri, 21 Oct 2016 12:12:45 GMT],
ETag=["E1AD5F8F9D75346DEC7F4B8A0B50DFE0"],
Last-Modified=[Mon, 17 Oct 2016 06:19:12 GMT],
Server=[AliyunOSS],
X-Android-Received-Millis=[1477051965326],
X-Android-Response-Source=[NETWORK 200],
X-Android-Selected-Protocol=[http/1.1],
X-Android-Sent-Millis=[1477051965264],
x-oss-hash-crc64ecma=[8743997218632548925],
x-oss-meta-md5=[E1AD5F8F9D75346DEC7F4B8A0B50DFE0],
x-oss-object-type=[Normal],
x-oss-request-id=[580A063D686D4261EF029556],
x-oss-server-time=[49]}