You may take a look at the Json-lib Java library, that provides XML-to-JSON conversion.
String xml = "<hello><test>1.2</test><test2>123</test2></hello>";
XMLSerializer xmlSerializer = new XMLSerializer();
JSON json = xmlSerializer.read( xml );
If you need the root tag too, simply add an outer dummy tag:
String xml = "<hello><test>1.2</test><test2>123</test2></hello>";
XMLSerializer xmlSerializer = new XMLSerializer();
JSON json = xmlSerializer.read("<x>" + xml + "</x>");
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