public static byte[] callMapToXML(Map map) {
		logger.info("将Map转成Xml,Map：" + map.toString());
		StringBuffer sb = new StringBuffer();
		sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?><bizdata>");
		mapToXMLTest2(map,sb);
		sb.append("</bizdata>");
		logger.info("将Map转成Xml,Xml：" + sb.toString());
		try {
			return sb.toString().getBytes("UTF-8");
		} catch (Exception e) {
			logger.error(e);
		}
		return null;
	}

	private static void mapToXMLTest2(Map map,StringBuffer sb) {
		Set set = map.keySet();
		for (Iterator it = set.iterator(); it.hasNext();) {
			String key = (String) it.next();
			Object value = map.get(key);
			if (null == value)
				value = "";
			if (value.getClass().getName().equals("java.util.ArrayList")) {
				ArrayList list = (ArrayList) map.get(key);
				sb.append("<" + key + ">");
				for (int i = 0; i < list.size(); i++) {
					HashMap hm = (HashMap) list.get(i);
					mapToXMLTest2(hm,sb);
				}
				sb.append("</" + key + ">");

			} else {
				if (value instanceof HashMap) {
					sb.append("<" + key + ">");
					mapToXMLTest2((HashMap) value,sb);
					sb.append("</" + key + ">");
				} else {
					sb.append("<" + key + ">" + value + "</" + key + ">");
				}

			}

		}
	}

待转化的多层级map代码：

public static void main(String[] args) {
		Map<String,Object> dataMap = new LinkedHashMap<String,Object>(); //默认
		dataMap.put("rtnCode","02");
		dataMap.put("rtnMsg","查询失败");
		dataMap.put("idWltCloudDistrict","专区id");
		
		Map<String,Object> bizMap = new LinkedHashMap<String,Object>();
		bizMap.put("serviceId","serviceId001");
		bizMap.put("data",dataMap);//data节点是一个map
		
		Map<String,Object> objMap = new LinkedHashMap<String,Object>();
		objMap.put("idWltCloudDistrict","专区id");
		objMap.put("districtName","专区名称");
		objMap.put("validateDateStart","专区有效期开始");
		objMap.put("validateDateEnd","专区有效期结束");
		objMap.put("status","专区状态(00-待发布;01-销售中; 02-已下架;)");
		objMap.put("partnerId","合作伙伴id");
		objMap.put("channelId","渠道id");
		objMap.put("areaId","商圈专区id");
		dataMap.putAll(objMap); //
		
		List<Map<String,Object>> prodKindList1 = new ArrayList<Map<String,Object>>();
		for(int i=1;i<=2;i++){
			// 第二层
			List<Map<String,Object>> prodKindList2 = new ArrayList<Map<String,Object>>();
			for(int j=1;j<=2;j++){
				Map<String,Object> prodKindObj2 = new LinkedHashMap<String,Object>();
				prodKindObj2.put("idWltCloudProdKind","类目ID");
				prodKindObj2.put("prodKindName","类目名称");
				prodKindObj2.put("prodKindIdx","类目序号");
				Map<String,Object> prodKind2 = new LinkedHashMap<String,Object>();
				prodKind2.put("prodKind",prodKindObj2);
				prodKindList2.add(prodKind2);
			}
			
			//第一层
			Map<String,Object> prodKindOjb1 = new LinkedHashMap<String,Object>();
			prodKindOjb1.put("idWltCloudProdKind","类目ID");
			prodKindOjb1.put("prodKindName","类目名称");
			prodKindOjb1.put("prodKindIdx","类目序号");
			prodKindOjb1.put("prodKindList",prodKindList2);
			Map<String,Object> prodKind1 = new LinkedHashMap<String,Object>();
			prodKind1.put("prodKind",prodKindOjb1);
			prodKindList1.add(prodKind1);
		}
		
		dataMap.put("prodKindList",prodKindList1);
		
		XmlCommonUtil.callMapToXML(bizMap);
	}

<?xml version="1.0" encoding="utf-8"?>
<bizdata>
    <serviceId>serviceId001</serviceId>
    <data>
        <rtnCode>02</rtnCode>
        <rtnMsg>查询失败</rtnMsg>
        <idWltCloudDistrict>专区id</idWltCloudDistrict>
        <districtName>专区名称</districtName>
        <validateDateStart>专区有效期开始</validateDateStart>
        <validateDateEnd>专区有效期结束</validateDateEnd>
        <status>专区状态(00-待发布;01-销售中; 02-已下架;)</status>
        <partnerId>合作伙伴id</partnerId>
        <channelId>渠道id</channelId>
        <areaId>商圈专区id</areaId>
        <prodKindList>
            <prodKind>
                <idWltCloudProdKind>类目ID</idWltCloudProdKind>
                <prodKindName>类目名称</prodKindName>
                <prodKindIdx>类目序号</prodKindIdx>
                <prodKindList>
                    <prodKind>
                        <idWltCloudProdKind>类目ID</idWltCloudProdKind>
                        <prodKindName>类目名称</prodKindName>
                        <prodKindIdx>类目序号</prodKindIdx>
                    </prodKind>
                    <prodKind>
                        <idWltCloudProdKind>类目ID</idWltCloudProdKind>
                        <prodKindName>类目名称</prodKindName>
                        <prodKindIdx>类目序号</prodKindIdx>
                    </prodKind>
                </prodKindList>
            </prodKind>
            <prodKind>
                <idWltCloudProdKind>类目ID</idWltCloudProdKind>
                <prodKindName>类目名称</prodKindName>
                <prodKindIdx>类目序号</prodKindIdx>
                <prodKindList>
                    <prodKind>
                        <idWltCloudProdKind>类目ID</idWltCloudProdKind>
                        <prodKindName>类目名称</prodKindName>
                        <prodKindIdx>类目序号</prodKindIdx>
                    </prodKind>
                    <prodKind>
                        <idWltCloudProdKind>类目ID</idWltCloudProdKind>
                        <prodKindName>类目名称</prodKindName>
                        <prodKindIdx>类目序号</prodKindIdx>
                    </prodKind>
                </prodKindList>
            </prodKind>
        </prodKindList>
    </data>
</bizdata>