title: A HTML validator in Java
body: <p>I want validate HTML code in Java.</p>
  
  <p>Like this:</p>
  
  <pre><code>HTMLValidator.validateHTML("aaa&lt;b&gt;bbb&lt;b&gt;");
  // Returns false, because tag &lt;b&gt; is not closed
  </code></pre>
  
  <p>What Java libraries exist to do this?</p>