title: get part of the file name from each file in a list in java
body: <p>I am uploading files in a list into S3 using <code>uploadFileList()</code>
  So this API takes list (records) as parameter like below </p>
  
  <pre><code>MultipleFileUpload xfer = tm.uploadFileList(bucketName, "TEST",new File(fileLocation), records);
  </code></pre>
  
  <p>The records in a list like this </p>
  
  <pre><code>21564_114762642_ANA_9ECB7C98-C2D7-428A-B6AD-7A6C62E1A7BE_App.xml.gz
  21224_114762642_ANA_9ECB7C98-C2D7-428A-B6AD-7A6C62E1A7BE_App.xml.gz
  20780_114762642_ANA_9ECB7C98-C2D7-428A-B6AD-7A6C62E1A7BE_App.xml.gz
  20407_114762642_ANA_9ECB7C98-C2D7-428A-B6AD-7A6C62E1A7BE_App.xml.gz
  </code></pre>
  
  <p>This is working fine as of now .
  Now i need to add prefix in the API as the first four digit of the file name like <code>21564</code> will be the prefix for the first file 
  So to do this i have to iterate over the list and add file by file but that will slow down the upload into S3 compare to uploading list .</p>
  
  <p>Is there anyway to add prefix while uploading list into S3 and the files in the list are random but pattern is fix ?</p>