title: Converting hexadecimal to binary in java
body: <p>I try to do:</p>
  
  <pre><code>String x = "He34llo";
  int i = Integer.parseInt(x, 16);
  String xx = Integer.toBinaryString(i);
  </code></pre>
  
  <p>But I get an <code>exception in thread "main" java.lang.NumberFormatException: For input string: "He34llo"</code></p>