title: regular expression to find special character & between xml tags
body: <p>A xml string generated from another model will pass to me, it may contains some special character such as &amp; in the text of the xml tag.<br>
  e.g.</p>
  
  <pre><code>&lt;entry&gt;
   &lt;key&gt;state&lt;/key&gt;
   &lt;value xsi:type="xs:string"&gt;ADDDRESS  3 &amp; ADDR 4, 12345, HONG KONG&lt;/value&gt;
  &lt;/entry&gt;
  </code></pre>
  
  <p>when I build the xml from string will have invalid character error, So I need to escape the special character <code>&amp;</code>.<br>
  I want to use regex to find the <code>&amp;</code> between <code>&lt;value&gt;&lt;/value&gt;</code> tag and replace with the <code>&amp;amp;</code><br>
  I have tried some but fail on the regex.</p>
  
  <p>Can anyone give me the some clue on the regex?</p>
  
  <p>besides I use Java 1.6</p>