添加jar包 dom4j.jar jaxen.jar
//String转XML
String xmlStr="<?xml version='1.0' encoding='UTF-8'?><REQUEST><CONTROL><REQUEST_ID>111</REQUEST_ID><SERVICE_ID></SERVICE_ID><APP_ID></APP_ID><APP_KEY></APP_KEY><ACCESS_TOKEN></ACCESS_TOKEN><HASH></HASH><EXT></EXT><REQUEST_TIME></REQUEST_TIME></CONTROL><DATA><USER><NAME>zsz</NAME><ID_TYPE></ID_TYPE><ID_NO></ID_NO><FROM_SYSTEM>taiping</FROM_SYSTEM></USER></DATA></REQUEST>";
Document document = DocumentHelper.parseText(xmlStr);
Element root=document.getRootElement();
String flag=document.selectSingleNode("REQUEST/DATA/USER/NAME").getText();
System.out.println(flag);
// XML转字符串
//Document document = ...;
String text = document.asXML();
System.out.println(text);