title: Evaluate formula after replacing dependent cells using Apache POI
body: <p>I am able to both read and write cell values using Apache POI. When reading, I evaluate first so that I get the correct values. My use case requires that I read a sheet, replace a few values in the sheet, then read another portion of the sheet that contains cells that depend on the cells I just replaced.</p>
  
  <p>Example.</p>
  
  <p><code>A1</code> contains a formula: <code>=B1+C1</code>. <code>B1</code> contains <code>2</code> and <code>C1</code> contains <code>3</code>. When I evaluate <code>A1</code> I correctly get <code>5</code>. Now, if I replace, with POI api, <code>C1</code> with <code>10</code>, I would expect that when I read <code>A1</code> again I would see <code>12</code>. I don't... <code>A1</code> now evaluates to <code>null</code>.</p>
  
  <p>Help!</p>