开启expires模块，a2enmod expires
然后在.htaccess文件中添加以下内容：
########## Begin - ETag Optimization
## This rule will create an ETag for files based only on the modification
## timestamp and their size.
## Note: It may cause problems on your server and you may need to remove it
FileETag MTime Size
# AddOutputFilterByType is now deprecated by Apache. Use mod_filter in the future.
AddOutputFilterByType DEFLATE text/plain text/html text/xml text/css application/xml application/xhtml+xml application/rss+xml application/javascript application/x-javascript
# Enable expiration control
ExpiresActive On
# Default expiration: 1 hour after request
ExpiresDefault "now plus 1 hour"
# CSS and JS expiration: 1 week after request
ExpiresByType text/css "now plus 1 week"
ExpiresByType application/javascript "now plus 1 week"
ExpiresByType application/x-javascript "now plus 1 week"
# Image files expiration: 1 month after request ExpiresByType image/bmp "now plus 1 month" ExpiresByType image/gif "now plus 1 month" ExpiresByType image/jpeg "now plus 1 month" ExpiresByType image/jp2 "now plus 1 month" ExpiresByType image/pipeg "now plus 1 month" ExpiresByType image/png "now plus 1 month" ExpiresByType image/svg+xml "now plus 1 month" ExpiresByType image/tiff "now plus 1 month" ExpiresByType image/vnd.microsoft.icon "now plus 1 month" ExpiresByType image/x-icon "now plus 1 month" ExpiresByType image/ico "now plus 1 month" ExpiresByType image/icon "now plus 1 month" ExpiresByType text/ico "now plus 1 month" ExpiresByType application/ico "now plus 1 month" ExpiresByType image/vnd.wap.wbmp "now plus 1 month" ExpiresByType application/vnd.wap.wbxml "now plus 1 month"
ExpiresByType application/smil "now plus 1 month" # Audio files expiration: 1 month after request ExpiresByType audio/basic "now plus 1 month" ExpiresByType audio/mid "now plus 1 month" ExpiresByType audio/midi "now plus 1 month" ExpiresByType audio/mpeg "now plus 1 month" ExpiresByType audio/x-aiff "now plus 1 month" ExpiresByType audio/x-mpegurl "now plus 1 month" ExpiresByType audio/x-pn-realaudio "now plus 1 month" ExpiresByType audio/x-wav "now plus 1 month"
# Movie files expiration: 1 month after request ExpiresByType application/x-shockwave-flash "now plus 1 month" ExpiresByType x-world/x-vrml "now plus 1 month" ExpiresByType video/x-msvideo "now plus 1 month" ExpiresByType video/mpeg "now plus 1 month" ExpiresByType video/mp4 "now plus 1 month" ExpiresByType video/quicktime "now plus 1 month" ExpiresByType video/x-la-asf "now plus 1 month" ExpiresByType video/x-ms-asf "now plus 1 month"