vim /usr/local/apache2/conf/extra/httpd-vhosts.conf
<IfModule mod_expires.c>
ExpiresActive on
ExpiresByType p_w_picpath/gif "access plus 1 days"
ExpiresByType p_w_picpath/jpeg "access plus 24 hours"
ExpiresByType p_w_picpath/png "access plus 24 hours"
ExpiresByType text/css "now plus 2 hour"
ExpiresByType application/x-javascript "now plus 2 hours"
ExpiresByType application/javascript "now plus 2 hours"
ExpiresByType application/x-shockwave-flash "now plus 2 hours"
ExpiresDefault "now plus 0 min"
</IfModule>