Android SDK下载和更新失败的解决方法！！！

最近刚换了电脑，开始搭建Android开发环境的时候，下载SDK总是会出现如下错误：

 Failed to fetch URL http://dl-ssl.google.com/android/repository/addons_list-1.xml.

据说dl-ssl.google.com在大陆被强了，伟大的天朝真是不让人活了，解决方法就是修改C:\Windows\System32\drivers\etc\hosts文件。添加一行：

 74.125.237.1       dl-ssl.google.com

这里需要注意的是hosts文件是只读的，我们没有权限修改，需要我们将hosts文件复制到桌面或者其他地方，然后修改，代码如下：

 # Copyright (c) 1993-2009 Microsoft Corp.
 #
 # This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
 #
 # This file contains the mappings of IP addresses to host names. Each
 # entry should be kept on an individual line. The IP address should
 # be placed in the first column followed by the corresponding host name.
 # The IP address and the host name should be separated by at least one
 # space.
 #
 # Additionally, comments (such as these) may be inserted on individual
 # lines or following the machine name denoted by a '#' symbol.
 #
 # For example:
 #
 #      102.54.94.97     rhino.acme.com          # source server
 #       38.25.63.10     x.acme.com              # x client host

 # localhost name resolution is handled within DNS itself.
 #   127.0.0.1       localhost
 #   ::1             localhost
 //亲，就是增加这一句哦
 74.125.237.1       dl-ssl.google.com

然后保存，复制修改后的hosts文件到 C:\Windows\System32\drivers\etc  目录，替换文件就好！！！我们再次下载SDK的时候就会成功啦，如下图：

嘿嘿，大功告成啦！！！

PS：补充下，在mac或Linux中，hosts文件所在位置为/etc/hosts，可以使用sudo vim /etc/hosts来编辑。