XML : Getting null while trying to convert and iterate XML string using java

I'm getting null while trying to convert XML object to document for iterating the object. Please find the code.

  String XML_DATA = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +          "<list>" +          "<string>abd5fd81-2bd6-4479-9d60-61fe533a13b7</string>" +          "<string>e127393b-343b-433c-87fc-27289758cca8</string>" +          "<string>753f79fe-a1d2-4383-b5c9-3ec8aa6b7e65</string>" +          "<string>2c71f819-65a6-4b08-8870-e71b1c770992</string>" +          "<string>ad22d8c0-8187-4243-8189-92e94c969208</string>" +          "<string>e6e70ab9-6149-4dfd-9d88-e27ec419847e</string>" +          "<string>87d8566b-4c8a-4ef0-9fa9-c7b8805e5631</string>" +          "<string>1309a729-20b4-40bb-96c8-46c96f205e60</string>" +          "<string>5e78b822-d472-4f02-859d-de36183c5d01</string>" +          "<string>410c70fb-8b05-47ef-bfbf-29284e45c8d3</string>" +          "</list>";    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  DocumentBuilder builder;  builder = factory.newDocumentBuilder();  System.out.println(builder.parse(new InputSource(new StringReader(XML_DATA))));//Displaying null  Document document = builder.parse(new InputSource(new StringReader(XML_DATA)));  System.out.println(document);