Send a Map (internally converted to XML) to a Web Service

I have a Map in Java and I want to send it to a Web Service. The Web Service expects an XML.

Example

Map<String, String> dummyMap = new HashMap<String, String>();

dummyMap.put("A", "a");
dummyMap.put("B", "b");
dummyMap.put("C", "c");
dummyMap.put("D", "d");

Is there a tool where I can send this Map that will be internally converted to an XML and sent to the Web Service in Java?