title: xssf How to get anything as String
body: <p>I try to parse an excel file into XML using apache poi xssf.
  Now having a cell and not knowing what is in it I just want to get a String out of it.
  But when I use</p>
  
  <pre><code>cell.getStringCellValue()
  </code></pre>
  
  <p>it throws an exception, what is not very suprising since it is documented this way.
  So I build my way around that by checking weather it is a numeric or a text cell. But what to do with formula cells. They may contain numbers like</p>
  
  <pre><code>= A2 + B2
  </code></pre>
  
  <p>What gives me the sum (e.g. 4) or a reference to another text</p>
  
  <pre><code>= C2
  </code></pre>
  
  <p>what might refer to a text like "Hans".</p>
  
  <p>How can I know what is really in my cell and how do I get a String out of it?</p>