title: Java collections convert a string to a list of characters
body: <p>I would like to convert the string containing <code>abc</code> to a list of characters and a hashset of characters. How can I do that in Java ? </p>
  
  <pre><code>List&lt;Character&gt; charList = new ArrayList&lt;Character&gt;("abc".toCharArray());
  </code></pre>