dom4j处理带命名空间的XML-使用XPath(转)

dom4j处理带命名空间的XML-使用XPath

博客分类：

 
• XML

 

XPath 是一门在 XML 文档中查找信息的语言。XPath 可用来在 XML 文档中对元素和属性进行遍历。

XPath 使用路径表达式来选取 XML 文档中的节点或节点集。节点是通过沿着路径 (path) 或者步 (steps) 来选取的。

w3school XPath教程

Dom4J学习笔记

 

例子1：

<report  xmlns="http://www.eclipse.org/birt/2005/design" version="3.2.15" id="1">
    <list-property name="cssStyleSheets">
        <structure>
            <property name="fileName">D: eport.css</property>
        </structure>
    </list-property>
</report>

 

第一个方案.设置你的xpath的命名空间setNamespaceURIs

    XPath x = document.createXPath("//design:list-property");

    x.setNamespaceURIs(map);

    x.selectNodes(document);

 

public class TransferXML {
    public static void main(String[] args) throws Exception{
        SAXReader saxReader = new SAXReader();
        File file = new File("D:\test.xml");
        Document document = saxReader.read(file);

        Map map = new HashMap();
        map.put("design","http://www.eclipse.org/birt/2005/design");
        XPath x = document.createXPath("//design:list-property");
        x.setNamespaceURIs(map);
        List nodelist = x.selectNodes(document);
        System.out.println(nodelist.size());
    }
}

 

 第二个解决方案:设置你的DocumentFactory()的命名空间 setXPathNamespaceURIs

    saxReader.getDocumentFactory().setXPathNamespaceURIs(map);

    Document document = saxReader.read(file);

    document.selectNodes("//design:list-property");

 

public class TransferXML {
    public static void main(String[] args) throws Exception{
        Map map = new HashMap();
        map.put("design","http://www.eclipse.org/birt/2005/design");
        SAXReader saxReader = new SAXReader();
        File file = new File("D:\test.xml");
        saxReader.getDocumentFactory().setXPathNamespaceURIs(map);
        Document document = saxReader.read(file);
        List tmp = document.selectNodes("//design:list-property");
        System.out.println(tmp.size());
    }
}

 

第三种方法：就是不使用开发环境给你提供的一系列对象，而是用XPath语法中自带的local-name() 和 namespace-uri() 指定你要使用的节点名和命名空间。

当你遇到使用xslt来样式化xml时，就知道这个笨方法的好处了：

    Document document =  saxReader.read(file);

    List tmp = document.selectNodes("//*[local-name()='report' and namespace-uri()='http://www.eclipse.org/birt/2005/design']/* [local-name()='list-property']");

 

public class TransferXML {
    public static void main(String[] args) throws Exception
        SAXReader saxReader = new SAXReader();
        File file = new File("D:\test.xml");
        Document document = saxReader.read(file);
        List tmp = document.selectNodes("//*[local-name()='report' and namespace-uri()='http://www.eclipse.org/birt/2005/design']/* [local-name()='list-property']");
        System.out.println(tmp.size());
    }
}

 

例子2：

 

<?xml version="1.0" encoding="UTF-8"?>

<addresses  xmlns="http://www.example.org/cameraServerAddress" >

    <address>
        <db>r1app.nvts.co</db>
        <zh>美国东1</zh>
        <en>US-East1</en>
    </address>
    <address>
        <db>r2app.nvts.co</db>
        <zh>日本1</zh>
        <en>JP-1</en>
    </address>

    <address>
        <db>r3app.nvts.co</db>
        <zh>欧洲1</zh>
        <en>EU-1</en>
    </address>
</addresses>

 

/**
     * 初始化CameraServerAddress，从xml配置文件初始化
     */
    @SuppressWarnings("unchecked")
    public void initCameraServerAddresses(){
        try {
            Map<String,String> uris = new HashMap<String, String>();
            uris.put("cameraServerAddress"  , "http://www.example.org/cameraServerAddress");
            SAXReader reader = new SAXReader();
            Document root = reader.read(this.getClass().getClassLoader().getResourceAsStream("cameraServerAddresses.xml"));
            XPath xpath = root.createXPath("//cameraServerAddress:address");    //创建XPath
            xpath.setNamespaceURIs(uris);   //加入NameSpace
            List<DefaultElement> nodes = xpath.selectNodes(root); //执行搜索
            for (DefaultElement de : nodes) {
                   de.add(new Namespace("cameraServerAddress", "http://www.example.org/cameraServerAddress"));  //这里也要再次加入NameSpace
                   Node db = de.selectSingleNode("cameraServerAddress:db");
                   Node zh =  de.selectSingleNode("cameraServerAddress:zh");
                   Node en = de.selectSingleNode("cameraServerAddress:en");
                   NVContext.cameraServerAddresses.add(new CameraServerAddress(
                           db.getText(), zh.getText(), en.getText()));
            }

        } catch (Exception e) {
            log.error("初始化CameraServerAddress失败");
            e.printStackTrace();
        }

    }

 

例子3（自己例子）：

<?xml version="1.0" encoding="UTF-8"?>

<webservices xmlns="http://ws.test.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="webservices.xsd">
  <webservice wsname="ws1" wsversion="">
    <wsdlurl>http://localhost:8888/ws1?wsdl</wsdlurl>
  </webservice>
  <webservice wsname="ws2">
    <wsdlurl>http://localhost:8888/ws2?wsdl</wsdlurl>
  </webservice>
  <webservice wsname="ws3" wsversion="v1">
    <wsdlurl>http://localhost:8888/ws3?wsdl</wsdlurl>
  </webservice>
  <webservice wsname="srv4">
    <wsdlurl>http://localhost:8889/ws4?wsdl</wsdlurl>
  </webservice>
  <webservice wsname="ESB_YS_YS_InquiryMachineInfoSrv">
    <wsdlurl>http://10.204.104.87:8888/ESB_YS_YS_InquiryMachineInfoSrv/ESBYSYSInquiryMachineInfoSrv?wsdl</wsdlurl>
  </webservice>
</webservices>

  

/**
     * 添加或更新单个webservice子节点
     * @param wi 封装的服务信息
     */
    public synchronized void addOrUpdate(WebserviceNode wi) {
        if(doc != null){
            Element root = doc.getRootElement();

            addOrUpdateWebservice(wi, root);

            save();
        }
    }

 

 

/**
     * 在指定的节点上添加webservice子节点
     *
     * @param wi 封装的服务信息
     * @param root root节点
     */
    private void addOrUpdateWebservice(WebserviceNode wi, Element root) {
        removeWebservices(wi, root);

        addOrUpdateWebserviceElement(wi, root);

        wis.add(wi);
    }

 

private void removeWebservices(WebserviceNode wi, Element root) {
        List<Element> es = findWebserviceElements(wi, root);

        if(es.size() > 0){
            // 删除doc中的元素
            for(Element e : es){
                root.remove(e);
            }
            // 删除集合中的元素
            Iterator<WebserviceNode> wiIterator = wis.iterator();
            while(wiIterator.hasNext()){
                WebserviceNode i = wiIterator.next();
                if(i.equals(wi)){
                    wiIterator.remove();
                }
            }
        }
    }

 

查找满足条件的子节点：

/**
     * 查找匹配的webservice元素
     *
     * @param wi
     * @param root
     * @return
     */
    @SuppressWarnings("unchecked")
    private List<Element> findWebserviceElements(WebserviceNode wi, Element root) {
        Map<String, String> ns = new HashMap<String, String>();
        ns.put("vis", "http://ws.test.com");

        String xpath = "/vis:webservices/vis:webservice[@wsname='"+ wi.getWsName() + "'" + (wi.hasVersionInfo() ? " and @wsversion='" + wi.getWsVersion() + "'" : " and (not(@wsversion) or normalize-space(@wsversion)='')") + "]";
        XPath x = root.createXPath(xpath);
        x.setNamespaceURIs(ns);

        //System.out.println(xpath);

        List<Element> es = x.selectNodes(root);
        return es;
    }

 

/**
     * 在指定的节点上添加webservice子节点(xml document)
     *
     * @param wi
     * @param root
     */
    private void addOrUpdateWebserviceElement(WebserviceNode wi, Element root) {
        Element ws = root.addElement("webservice");
        ws.addAttribute("wsname", wi.getWsName());
        if(wi.hasVersionInfo()){
            ws.addAttribute("wsversion", wi.getWsVersion());
        }
        ws.addElement("wsdlurl").setText(wi.getWsdlUrl());
    }

 保存XML文件：

/**
     * 保存至硬盘
     */
    private void save() {
        // 将document保存至硬盘
        OutputFormat format = OutputFormat.createPrettyPrint();
        try {
            XMLWriter writer = new XMLWriter(new FileWriter(PATH), format);
            writer.write(doc);
            writer.close();
        } catch (IOException e) {
            System.err.println("Persist '" + PATH + "' is Failed...");
            e.printStackTrace();
        }
    }