dom4j处理带命名空间的XML-使用XPath

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();
		}
	}

 。。