中国省市区三级联动的JCombobox源代码

package com.qiantu.component; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.List; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; public class XMLDao { /** * 根据某个城市获取此省市的所有地区 * @param districts * @return */ public static List<String> getDistricts(String districts) { List<String> list = new ArrayList<String>(); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); try { factory.setIgnoringElementContentWhitespace(true); DocumentBuilder db = factory.newDocumentBuilder(); Document xmldoc = db.parse(new File("xml/Districts.xml")); Element root = xmldoc.getDocumentElement(); NodeList nodes = selectNodes("//District[@city='"+districts+"']", root); for(int i=0; i<nodes.getLength(); i++) { Node node = nodes.item(i); String name = node.getTextContent(); list.add(name); } } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return list; } /** * 根据某个省份的名字获取此省份的所有城市 * @param provinces * @return */ public static List<String> getCities(String provinces) { List<String> list = new ArrayList<String>(); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); try { factory.setIgnoringElementContentWhitespace(true); DocumentBuilder db = factory.newDocumentBuilder(); Document xmldoc = db.parse(new File("xml/Cities.xml")); Element root = xmldoc.getDocumentElement(); NodeList nodes = selectNodes("//City[@Province='"+provinces+"']", root); for(int i=0; i<nodes.getLength(); i++) { Node node = nodes.item(i); String name = node.getTextContent(); list.add(name); } } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return list; } /** * 获取所有省份 * @return */ public static List<String> getProvinces() { List<String> list = new ArrayList<String>(); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); try { factory.setIgnoringElementContentWhitespace(true); DocumentBuilder db = factory.newDocumentBuilder(); Document xmldoc = db.parse(new File("xml/Provinces.xml")); Element root = xmldoc.getDocumentElement(); NodeList nodes = selectNodes("/Provinces/Province", root); for(int i=0; i<nodes.getLength(); i++) { Node node = nodes.item(i); String name = node.getTextContent(); list.add(name); } } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return list; } /** * 根据xpath获取某一个节点 * @param express * @param source * @return */ public static Node selectSingleNode(String express, Object source) {// 查找节点，并返回第一个符合条件节点 Node result = null; XPathFactory xpathFactory = XPathFactory.newInstance(); XPath xpath = xpathFactory.newXPath(); try { result = (Node) xpath .evaluate(express, source, XPathConstants.NODE); } catch (XPathExpressionException e) { e.printStackTrace(); } return result; } /** * 根据xpath获取符合条件的所有节点 * @param express * @param source * @return */ public static NodeList selectNodes(String express, Object source) {// 查找节点，返回符合条件的节点集。 NodeList result = null; XPathFactory xpathFactory = XPathFactory.newInstance(); XPath xpath = xpathFactory.newXPath(); try { result = (NodeList) xpath.evaluate(express, source, XPathConstants.NODESET); } catch (XPathExpressionException e) { e.printStackTrace(); } return result; } }