title: Routing data to multiple files in item writer based on item's property as criteria
body: <p>I am getting a list of items in my reader. </p>
  
  <p>There is a property called <code>Code</code> in each item object having several possible values not known to me before hand. </p>
  
  <p>1) Based on the value of <code>Code</code>in each item, I want to write that particular item in a output file pertaining to that <code>Code</code>. For e.g. if my current item's <code>Code</code> is "abc", the item should be written in to abc.txt in the writer. </p>
  
  <p>2) If there is a <code>Code</code> "xyz" in current item, for which the file is not present, a new file should get created and the item should go to that file. </p>
  
  <p>3) For all such multiple files created based on <code>Code</code>, I also want to add a header and footer call back to enter some details e.g. count of items in each file. </p>
  
  <p>Is it possible to have a writer, which satisfies above 3 requirements ?</p>
  
  <p>I know that using multiresourceitemwriter, one can divide the data among multiple output files. But as far as I know, this division is based on the number of items. For e.g. first 10 items in file1, next 10 in file2 and so on. </p>
  
  <p>But how to route data to output files based on an item property as mentioned in my question ?</p>
  
  <p>I am well acquainted with Spring Batch and just need a little guidance since this is the first time I am facing this kind of issue.</p>
  
  <p>Thanks for reading! </p>