JSON is much popular now, but occasionally it is still possible to come across XML API.
I had such experience recently and I have to say that in 2016 it is much easier than some 10 years ago.
I mostly use Jackson for JSON, so for me best way to use it is XmlMapper plugin. After that it is plain Jackson.
There is example:
There is example:
XmlMapper mapper = new XmlMapper();
List rates = mapper.readValue(ratesString, List.class);
compile 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.6.3'
compile 'org.codehaus.woodstox:woodstox-core-asl:4.4.1'