title: delete all files in nested folders with name that contains "_bla"
body: <p>I have a structure of nested folders</p>
  
  <p>I want to delete all the files (not folders) in that structure which contains the name "_bla"</p>
  
  <p>here is my code but it's pretty cumbersome</p>
  
  <p>do you know of a neater way to do that?</p>
  
  <pre><code>cleanDirectoryAccordingToBlackList(Constants.RESOURCES_PATH, ImmutableList.of("_bla"));
  </code></pre>
  
  <p>and </p>
  
  <pre><code>  public void cleanDirectoryAccordingToBlackList(String root, List&lt;String&gt; blackList) {
          File dir = new File(root);
          if (dir.isDirectory()) {
              File[] files = dir.listFiles();
              if (files != null &amp;&amp; files.length &gt; 0) {
                  for (File aFile : files) {
                      removeFilesInDirectory(aFile, blackList);
                  }
              }
          }
      }
  
      public void removeFilesInDirectory(File file, List&lt;String&gt; blackList) {
          if (file.isDirectory()) {
              File[] files = file.listFiles();
              if (files != null &amp;&amp; files.length &gt; 0) {
                  for (File aFile : files) {
                      removeFilesInDirectory(aFile, blackList);
                  }
              }
          } else {
              for (String name : blackList) {
                  if (file.getName().contains(name)) {
                      file.delete();
                  }
              }
          }
      }
  </code></pre>