title: How to compare two excel sheets
body: <p>I have two excel files and I need to compare them. </p>
  
  <p>Main case is that the user downloads the file, makes some changes, and uploads it back. After that the system compare them and show a discrepancy report. </p>
  
  <p>I use Apache POI, and I try to understand how track some user actions. E.g. user rename all the cells in a row, then moves it up. How to track these changes?</p>
  
  <p>The problem is if I compare the new file with his last copy it looks like the user deleted one row and created another, instead of renaming and moving it. </p>
  
  <p>I have read that Excel can track user <a href="https://support.office.microsoft.com/en-us/article/Track-changes-in-a-shared-workbook-951bdf89-9ee6-4777-b31e-33ad0f594d18?CorrelationId=2cfa97f9-b784-4dc5-9e38-d672babb702b&amp;ui=en-US&amp;rs=en-001&amp;ad=US" rel="nofollow">changes</a> and can create change logs but I don't find any mentions of this feature in POI. This is one idea how to solve this problem, but I think it's not a good one.</p>
  
  <p>So what is the best way to handle these user actions?</p>