The only problem with JSON in Java is that if your XML has a single child, but is an array, it will convert it to an object instead of an array. This can cause problems if you dynamically always convert from XML to JSON, where if your example XML has only one element, you return an object, but if it has 2+, you return an array, which can cause parsing issues for people using the JSON.
Infoscoop's XML2JSON class has a way of tagging elements that are arrays before doing the conversion, so that arrays can be properly mapped, even if there is only one child in the XML.
Here is an example of using it (in a slightly different language, but you can also see how arrays is used from the nodelist2json() method of the XML2JSON link).