dom解析xml实现省市区动态级联

dom解析xml实现省市区动态级联是一个项目中的一部分，项目是springMVC实现的，其配置文件这儿就不在说了，现只简单列出一些主要的代码。看懂需要有一定的springMVC基础

配置文件中的省的值

city.area.province=黑龙江,湖南

在action中

private @Value("${city.area.province}") String provinceStr;

model.addAttribute("provinceList", ManagerUtil.getSelectBean(provinceStr));//获取省的下拉列表

//根据省获取市
public void getCityListByProvince(@RequestParam("province") String province,
			Model model, HttpServletResponse response) {
		try {
			province = URLDecoder.decode(province, "utf-8");
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		}
		response.setCharacterEncoding("utf-8");
		getListValue("province", "city", province, response);
	}
//根据市获取区县
public void getAreaListByCity(@RequestParam("city") String city,
			Model model, HttpServletResponse response) {
		try {
			city = URLDecoder.decode(city, "utf-8");
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		}
		response.setCharacterEncoding("utf-8");
		getListValue("city", "area", city, response);
		
	}
//
private void getListValue(String type, String childType, String value, HttpServletResponse response) {
		StringBuilder sb = new StringBuilder();
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		
		try {
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document document = builder.parse(new File(UserController.class.getResource("/").toString().substring(6) 
					+ "/city-area.xml"));
			NodeList nodeList = document.getElementsByTagName(type);
			
			for(int i=0; i<nodeList.getLength(); i++) {
				Element e = (Element) nodeList.item(i);
				String name = e.getAttribute("name");
				if(name.equals(value)){
					NodeList childList = e.getElementsByTagName(childType) ;
					for(int j=0; j<childList.getLength(); j++) {
						sb.append(",").append(((Element) childList.item(j)).getAttribute("name"));
					}
					break;
				}
			}
		}catch(SAXException  e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch(ParserConfigurationException  e) {
			e.printStackTrace();
		}
		try {
			response.getWriter().write(JsonUtil.toJsonString(ManagerUtil.getSelectBean(sb.substring(1).toString())));
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

JsonUtil类的toJsonString方法

public static String toJsonString(Object o) {
		if(o instanceof Collection) {
			StringBuffer buf = new StringBuffer("");
			Object[] objs = JSONArray.fromObject(o).toArray();
			for (int i = 0; i < objs.length; i ++) {
				if(i!=0) buf.append(",");
				buf.append(JSONObject.fromObject(objs[i]).toString());
			}
			return "{totalCount:" + objs.length + ",root:[" + buf.toString() + "]}";
		}
		return JSONObject.fromObject(o).toString();
	}

ManagerUtil类中的getSelectBean方法

public static List<SelectBean> getSelectBean(String str) {
		List<SelectBean> selectBeanList = new ArrayList<SelectBean>();
		if (!StringUtils.isEmpty(str)) {
			for (String item : str.split(",")) {
				SelectBean selectBean = new SelectBean();
				selectBean.setLabel(item.trim());
				selectBean.setValue(item.trim());
				selectBeanList.add(selectBean);
			}
		}
		return selectBeanList;
	}

jsp主要部分

<script type="text/javascript">function changeCityList(obj) {
		var citySelect = $("#uCity");
		var areaSelect = $("#uArea");
		citySelect.empty();
		areaSelect.empty();
		citySelect.append("<option value=''>请选择市</option>");
		areaSelect.append("<option value=''>请选择区/县</option>");
		if($(obj).val() != '') {
			$.ajax({
	 			type: "POST",
	 			 url: '....../getCityListByProvince.do?province=' + 
	 					 encodeURIComponent(encodeURIComponent($(obj).val())),
	 			async:false,
	 			dataType:'text',
	 			success: function(json) {
	 				
	 				var data = (eval('(' + json + ')')).root;
	 				for(var i=0; i<data.length; i++){
	 					citySelect.append("<option value=" + data[i].value + ">" + data[i].label + "</option>");
					}
	 			}
	 		});
		}
	}
	
	function changeAreaList(obj) {
//		alert($(obj).val());
		var areaSelect = $("#uArea");
		areaSelect.empty();
		areaSelect.append("<option value=''>请选择区/县</option>");
		if($(obj).val() != ''){
			$.ajax({
	 			type: "POST",
	 			 url: '...../getAreaListByCity.do?city=' + 
	 					 encodeURIComponent(encodeURIComponent($(obj).val())),
	 			async:false,
	 			dataType:'text',
	 			success: function(json) {
	 	//			var areaSelect = $("#uArea");
	 				var data = (eval('(' + json + ')')).root;
	 				for(var i=0; i<data.length; i++){
	 					areaSelect.append("<option value=" + data[i].value + ">" + data[i].label + "</option>");
					}
	 			}
	 		});
		}
		
	}
</script>
<div class="rfm">
			<table>
			<tr>
			<th><span class="rq">*</span><label for="369bQT">省:</label></th>
			<td>
				<select id="uProvince" onchange="changeCityList(this)" name="uProvince" style="width:230px">
					<option value="">请选择省份</option>
					<c:forEach items="${provinceList }" var="province">
						<option value="${province.value }">${province.label }</option>
					</c:forEach>
				</select>
			</td>
			</tr>
			</table>
			</div>
			<div class="rfm">
			<table>
			<tr>
			<th><span class="rq">*</span><label for="369bQT">市:</label></th>
			<td>
				<select id="uCity" name="uCity" onchange="changeAreaList(this)" style="width:230px">
					<option value="">请选择市</option>
				</select>
			</td>
			</tr>
			</table>
			</div>
			<div class="rfm">
			<table>
			<tr>
			<th><span class="rq">*</span><label for="369bQT">区:</label></th>
			<td>
				<select id="uArea" name="uArea" style="width:230px">
					<option value="">请选择区/县</option>
				</select>
			</td>
			</tr>
			</table>
			</div>

city-area.xml的部分内容(这里主要是说明一下它的格式)

<?xml version="1.0" encoding="UTF-8" ?>  
<root name="中国">  
	<province name="黑龙江" id="黑龙江">
    	<city name="大庆市">  
			<area name="萨尔图区"/>
			<area name="龙凤区"/>
			<area name="让胡路区"/>
			<area name="红岗区"/>
			<area name="大同区"/>
			<area name="肇州县"/>
			<area name="肇源县"/>
			<area name="林甸县"/>
			<area name="杜尔伯特蒙古族自治县"/>
    	</city> 
    	<city name="七台河市">  
			<area name="桃山区"/>
			<area name="新兴区"/>
			<area name="茄子河区"/>
			<area name="勃利县"/>
    	</city>
	</province>
</root>