检查服务器文件大小

检查服务器文件大小

- (long long)serverFileInfoWithURL:(NSURL *)url{
    //1.请求
    NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:url cachePolicy:1 timeoutInterval:20];
    request.HTTPMethod = @"HEAD";
    //2.建立网络连接
    NSURLResponse * response = nil;
    [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:NULL];
    //3.记录服务器的文件信息
    //3.1 文件长度
    long long expectedContentLength = response.expectedContentLength;
    return expectedContentLength;
}