title: Firebase : How to check file already exist before Upload files
body: <p>I use firebase storage for cloud storage</p>
  
  <p>While uploading files I dont want to upload if the file is already exist in the storage reference. I just need to skip the upload and continue with the next file. </p>
  
  <p>Currently I upload like this </p>
  
  <pre><code>    String pathString = "/Files/" + filename;                        
      StorageReference filepathReference = rootreference.child(pathString);
      StorageReference uploadRef = filepathReference.child(pathString);
      UploadTask uploadTask = uploadRef.putFile(file);
  </code></pre>
  
  <p>Which, apparently upload again and replace if the file already exists. I just want to skip the unwanted upload by making a check for the filename already exist in the storage bucket.
  Is that possible?       </p>