title: How to move and overwrite all files from one directory to another?
body: <p>I know about the Methods in <code>FileUtils</code>, but the <code>FileUtils</code> won't overwrite.</p>
  
  <p>Also in <code>Files.move("", "", StandardCopyOption.REPLACE_EXISTING)</code> when the file exists and it's not empty, then the following exception is thrown: <code>java.nio.file.DirectoryNotEmptyException</code></p>
  
  <p>Sample:</p>
  
  <pre><code>/file1/test1
  /file2/test1
  </code></pre>
  
  <p>How do I merge, move, and overwrite (such as move in windows), <code>/file1/test1</code> to <code>/file2/test1</code> ?</p>
  
  <p>has java function for this job? I want don't write any method</p>