RewriteEngine on
RewriteBase /

RewriteRule ^DB/TE/(.+\.dat) /data/$1? [R=301,L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteCond %{REQUEST_FILENAME}index.html !-f
RewriteRule . /index.html [L]