In this post I will explain how you can configure Apache Tomcat, Apache Solr and Drupal 7 in about 5 minutes, taking into account that you have Drupal 7 installed in a Linux based server.
The first step is to install the Tomcat server if you have not already installed it:
aptitude install tomcat6 tomcat6-admin tomcat6-common tomcat6-user
Let's start the server and verify that works:
/etc/init.d/tomcat6 start
Next step is to download the Apache Solr Search Integration module for Drupal 7:
drush dl apachesolr
Now we can install Solr following the Apache Solr module README.txt. As it suggests