title: file:inbound-channel-adapter prevent-duplicates="false" is not working in spring boot application
body: <p>My application is a Spring Boot application. I have a directory named <code>abc</code>. I have created an inbound adapter to read the directory for new files. Let's assume a file <code>aa.txt</code> present in the directory. It is being picked up by the adapter. Now, let's say, again a new file with the same name has been saved in the directory. But, now the adapter does not get invoked.</p>
  
  <pre><code>&lt;file:inbound-channel-adapter id="inAdapter"
      directory="file:abc" filter="txtFiles"
      auto-startup="true" prevent-duplicates="false"&gt;
      &lt;int:poller id="poller" fixed-delay="5000" /&gt;
  &lt;/file:inbound-channel-adapter&gt;
  </code></pre>
  
  <p>I have set <code>prevent-duplicates=false</code>. Still, that file is not getting picked up. Why does this happen? What is the solution?</p>