标签:des Lucene style class blog code
Attribute定义了XML的属性
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Branch为能够包含子节点的节点如XML元素(Element)和文档(Docuemnts)定义了一个公共的行为,
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CDATA 定义了XML CDATA 区域
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CharacterData是一个标识借口,标识基于字符的节点。如CDATA,Comment, Text.
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Comment 定义了XML注释的行为
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定义了XML文档
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DocumentType 定义XML DOCTYPE声明
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Element定义XML 元素
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ElementHandler定义了 Element 对象的处理器
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被 ElementHandler 使用,用于取得当前正在处理的路径层次信息
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Entity定义 XML entity
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Node为所有的dom4j中XML节点定义了多态行为
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NodeFilter 定义了在dom4j节点中产生的一个滤镜或谓词的行为(predicate)
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ProcessingInstruction 定义 XML 处理指令.
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Text 定义XML 文本节点.
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Visitor 用于实现Visitor模式.
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XPath 在分析一个字符串后会提供一个XPath 表达式
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// 从文件读取XML,输入文件名,返回XML文档 public Document read(String fileName) throws MalformedURLException, DocumentException { SAXReader reader = new SAXReader(); Document document = reader.read(new File(fileName)); return document; }
public Element getRootElement(Document doc){ return doc.getRootElement(); }
3. 遍历XML树
// 枚举所有子节点 for ( Iterator i = root.elementIterator(); i.hasNext(); ) { Element element = (Element) i.next(); // do something } // 枚举名称为foo的节点 for ( Iterator i = root.elementIterator(foo); i.hasNext();) { Element foo = (Element) i.next(); // do something } // 枚举属性 for ( Iterator i = root.attributeIterator(); i.hasNext(); ) { Attribute attribute = (Attribute) i.next(); // do something }
2)递归
public void treeWalk() { treeWalk(getRootElement()); } public void treeWalk(Element element) { for (int i = 0, size = element.nodeCount(); i < size; i++) { Node node = element.node(i); if (node instanceof Element) { treeWalk((Element) node); } else { // do something.... } } }
public class MyVisitor extends VisitorSupport { public void visit(Element element){ System.out.println(element.getName()); } public void visit(Attribute attr){ System.out.println(attr.getName()); } } 调用: root.accept(new MyVisitor())
public void bar(Document document) { List list = document.selectNodes( //foo/bar ); Node node = document.selectSingleNode(//foo/bar/author); String name = node.valueOf( @name ); }
例如,如果你想查找XHTML文档中所有的超链接,下面的代码可以实现:
public void findLinks(Document document) throws DocumentException { List list = document.selectNodes( //a/@href ); for (Iterator iter = list.iterator(); iter.hasNext(); ) { Attribute attribute = (Attribute) iter.next(); String url = attribute.getValue(); } }
5. 字符串与XML的转换
// XML转字符串 Document document = ...; String text = document.asXML(); // 字符串转XML String text = James ; Document document = DocumentHelper.parseText(text);
6 用XSLT转换XML
public Document styleDocument( Document document, String stylesheet ) throws Exception { // load the transformer using JAXP TransformerFactory factory = TransformerFactory.newInstance(); Transformer transformer = factory.newTransformer( new StreamSource( stylesheet ) ); // now lets style the given document DocumentSource source = new DocumentSource( document ); DocumentResult result = new DocumentResult(); transformer.transform( source, result ); // return the transformed document Document transformedDoc = result.getDocument(); return transformedDoc; }
public Document createDocument() { Document document = DocumentHelper.createDocument(); Element root = document.addElement(root); Element author1 = root .addElement(author) .addAttribute(name, James) .addAttribute(location, UK) .addText(James Strachan); Element author2 = root .addElement(author) .addAttribute(name, Bob) .addAttribute(location, US) .addText(Bob McWhirter); return document; }
FileWriter out = new FileWriter( foo.xml ); document.write(out);
如果你想改变输出的格式,比如美化输出或缩减格式,可以用XMLWriter类
public void write(Document document) throws IOException { // 指定文件 XMLWriter writer = new XMLWriter( new FileWriter( output.xml ) ); writer.write( document ); writer.close(); // 美化格式 OutputFormat format = OutputFormat.createPrettyPrint(); writer = new XMLWriter( System.out, format ); writer.write( document ); // 缩减格式 format = OutputFormat.createCompactFormat(); writer = new XMLWriter( System.out, format ); writer.write( document ); }
如何,DOM4J够简单吧,当然,还有一些复杂的应用没有提到,如ElementHandler等。如果你动心了,那就一起来用DOM4J.
holen.xml <?xml version="1.0" encoding="UTF-8"?> <!--This is a test for dom4j, holen, 2004.9.11--> O‘Reilly
/** * 建立一个XML文档,文档名由输入属性决定 * @param filename 需建立的文件名 * @return 返回操作结果, 0表失败, 1表成功 */ public int createXMLFile(String filename){ /** 返回操作结果, 0表失败, 1表成功 */ int returnValue = 0; /** 建立document对象 */ Document document = DocumentHelper.createDocument(); /** 建立XML文档的根books */ Element booksElement = document.addElement("books"); /** 加入一行注释 */ booksElement.addComment("This is a test for dom4j, holen, 2004.9.11"); /** 加入第一个book节点 */ Element bookElement = booksElement.addElement("book"); /** 加入show属性内容 */ bookElement.addAttribute("show","yes"); /** 加入title节点 */ Element titleElement = bookElement.addElement("title"); /** 为title设置内容 */ titleElement.setText("Dom4j Tutorials"); /** 类似的完成后两个book */ bookElement = booksElement.addElement("book"); bookElement.addAttribute("show","yes"); titleElement = bookElement.addElement("title"); titleElement.setText("Lucene Studing"); bookElement = booksElement.addElement("book"); bookElement.addAttribute("show","no"); titleElement = bookElement.addElement("title"); titleElement.setText("Lucene in Action"); /** 加入owner节点 */ Element ownerElement = booksElement.addElement("owner"); ownerElement.setText("O‘Reilly"); try{ /** 将document中的内容写入文件中 */ XMLWriter writer = new XMLWriter(new FileWriter(new File(filename))); writer.write(document); writer.close(); /** 执行成功,需返回1 */ returnValue = 1; }catch(Exception ex){ ex.printStackTrace(); } return returnValue; }
/** * 修改XML文件中内容,并另存为一个新文件 * 重点掌握dom4j中如何添加节点,修改节点,删除节点 * @param filename 修改对象文件 * @param newfilename 修改后另存为该文件 * @return 返回操作结果, 0表失败, 1表成功 */ public int ModiXMLFile(String filename,String newfilename){ int returnValue = 0; try{ SAXReader saxReader = new SAXReader(); Document document = saxReader.read(new File(filename)); /** 修改内容之一: 如果book节点中show属性的内容为yes,则修改成no */ /** 先用xpath查找对象 */ List list = document.selectNodes("/books/book/@show" ); Iterator iter = list.iterator(); while(iter.hasNext()){ Attribute attribute = (Attribute)iter.next(); if(attribute.getValue().equals("yes")){ attribute.setValue("no"); } } /** * 修改内容之二: 把owner项内容改为Tshinghua * 并在owner节点中加入date节点,date节点的内容为2004-09-11,还为date节点添加一个属性type */ list = document.selectNodes("/books/owner" ); iter = list.iterator(); if(iter.hasNext()){ Element ownerElement = (Element)iter.next(); ownerElement.setText("Tshinghua"); Element dateElement = ownerElement.addElement("date"); dateElement.setText("2004-09-11"); dateElement.addAttribute("type","Gregorian calendar"); } /** 修改内容之三: 若title内容为Dom4j Tutorials,则删除该节点 */ list = document.selectNodes("/books/book"); iter = list.iterator(); while(iter.hasNext()){ Element bookElement = (Element)iter.next(); Iterator iterator = bookElement.elementIterator("title"); while(iterator.hasNext()){ Element titleElement=(Element)iterator.next(); if(titleElement.getText().equals("Dom4j Tutorials")){ bookElement.remove(titleElement); } } } try{ /** 将document中的内容写入文件中 */ XMLWriter writer = new XMLWriter(new FileWriter(new File(newfilename))); writer.write(document); writer.close(); /** 执行成功,需返回1 */ returnValue = 1; }catch(Exception ex){ ex.printStackTrace(); } }catch(Exception ex){ ex.printStackTrace(); } return returnValue; }
/** * 格式化XML文档,并解决中文问题 * @param filename * @return */ public int formatXMLFile(String filename){ int returnValue = 0; try{ SAXReader saxReader = new SAXReader(); Document document = saxReader.read(new File(filename)); XMLWriter writer = null; /** 格式化输出,类型IE浏览一样 */ OutputFormat format = OutputFormat.createPrettyPrint(); /** 指定XML编码 */ format.setEncoding("GBK"); writer= new XMLWriter(new FileWriter(new File(filename)),format); writer.write(document); writer.close(); /** 执行成功,需返回1 */ returnValue = 1; }catch(Exception ex){ ex.printStackTrace(); } return returnValue; }
Dom4j的使用(全而好的文章),布布扣,bubuko.com
标签:des Lucene style class blog code
原文地址:http://www.cnblogs.com/aixin0428/p/3791027.html