title: Classify documents with tags
body: <p>I have a huge amount of documents (mainly pdfs and doc's) I want to classify, so I can search over them according to certain tags. These tags could either be of my own (I put the tags to the document) or extracted from the text.</p>
  
  <p>I've just seen a post related to this (<a href="https://stackoverflow.com/questions/4137622/classify-data-using-apache-mahout">Classify data using Apache Mahout</a>), but perhaps there is something even more simple.</p>