title: Lucene TokenStream
body: <p>I have a basic question on the lucene tokenizing process:</p>
  
  <pre><code>TokenStream tokenStream = analyzer.tokenStream(fieldName, reader);    
  TermAttribute termAttribute = tokenStream.addAttribute(TermAttribute.class);
  </code></pre>
  
  <p>What is a termAttribute used for and what does tokenStream.addAttribute(TermAttribute.class) do?</p>
  
  <p>Thanks!</p>