How to merge multiple xml files into one using java?

I have multiple xml files. For example: File1.xml

<rows>
  <row>
    <id> 1 </id>
    <name> Kevin </name>
  </row>
</rows>

File2.xml

<rows>
  <row>
   <id> 2 </id>
   <name> Kris</name>
  </row>
</rows>

and so on.

I want to merge these files into one xml file. Is there any Java code to do that?