java教学电子知识点总结dom4j

1、DOM4J DOM4J DOM4J XML Dom4j is an easy to use, open source library for working with XML, XPath and XSLT on the Java platform using the Java Collections Framework and with full support for DOM, SAX and JAXP. DOM，SAX JAXP。（htmlIBMdeveloper社区的文章（参见附录XML 解析包的性能比较，其中 DOM4J （DOM4J 的官方文档中也引用了这个比较）DOM4J XML

2、 解析工具。JDOMDOM4J最大的特色是使用 DOM4JJDOM，不妨继续用下去，只看看本篇DOM4J 吧。org.dom4jAttributeXML BranchXML元素(Element)和文档(Docuemnts)定义了一个公共的CDATA XMLCDATA Comment XML XML DocumentType XMLDOCTYPE Element XML ElementHandler Element ElementHandler EntityXMLentity Node dom4j XML NodeFilter dom4j 节点中产生的一个滤镜或谓词的行为ProcessingIn

3、structionNodeFilter dom4j 节点中产生的一个滤镜或谓词的行为ProcessingInstruction XML 处理指令. Text XML 文本节点. Visitor Visitor模式. XPath XPath 表达式interface org.dom4j.Nodeinterface org.dom4j.Branchinterface org.dom4j.Elementinterface org.dom4j.CDATAinterface org.dom4j.Textinterface org.dom4j.EntityinterfaceClassCastExcepti

4、on 了。下面给出一些例子（DOM4J 自带的文档XML XMLorg.dom4j.io DOMReader SAXReader / XMLXML publicDocumentread(StringfileName)throwsMalformedURLException,DocumentException SAXReader reader = new SAXReader();Documentdocument=reader.read(newFile(fileName); return document;其中，readerreadInputStream, File, Url等多种不同的源来读取。D

5、ocument XML。XML 取得RootRoot XML XML return returnXML DOM4J 3 1) 枚举/ for(Iteratori=root.elementIterator();i.hasNext();) Element element = (Element) i.next();/do/ foo for(Iteratori=root.elementIterator(foo);i.hasNext();) Element foo = (Element) i.next();/do/ for(Iteratori=root.attributeIterator();i.has

6、Next();) Attribute attribute = (Attribute) i.next();/doIteratorpublicvoidtreeWalk()publicvoidtreeWalk(Elementelement)for(inti=0,size=element.nodeCount();isize;i+) Node node = element.node(i);if(nodeinstanceofElement) treeWalk(Element) node);else / do3)Visitor DOM4JVisitor的支持，这样可以大大缩减代码量，并且清楚易懂。了解设计模

7、式的人都知道，Visitor GOF VisitorVisitableDOM4JVisitorVisitorVisitableDOM4JVisitor模式(快速VisitorpublicclassMyVisitorextendsVisitorSupportpublicvoidvisit(Elementpublicvoidvisit(Attribute调用： root.accept(newVisitor 接口提供多种 Visit()的重载，根据 XML 不同的对象，将采用不同的方式来访问。上 注意，这个 Visitor 是自动遍历所有子节点的。如果是 root.accept(MyVisitor)

8、，将遍历子节Visitor，结果可想而知。4.XPath DOM4JXPath XPath publicvoidbar(Documentdocument)Listlist=document.selectNodes(/foo/barNodenode=document.selectSingleNode(/foo/bar/author); String name = node.valueOf( name );XHTML publicvoidfindLinks(Documentdocument)throwsDocumentExceptionList list = document.selectNode

9、s( /a/href ); for(Iteratoriter=list.iterator();iter.hasNext();)String url = attribute.getValue();5. XML XML XML Documentdocument=Stringtext=/ Stringtext=/ XML StringtextJamesDocumentdocument=6 XSLT publicDocumentString stylesheet)throwsException/loadthetransformerusingTransformer transformer = facto

10、ry.newTransformer(newStreamSource(stylesheet/nowletsstylethegivenDocumentSourcesource=newDocumentSource(document); DocumentResult result = new DocumentResult(); /returnthetransformedDocumenttransformedDoc=result.getDocument(); return transformedDoc;7. XMLStringBuffer publicDocumentcreateDocument()El

11、ement root = document.addElement(root);Elementauthor1= Element author2 = return document;8. DocumentNode8. DocumentNode write FileWriterout=newFileWriter(foo.xml publicvoidwrite(Documentdocument)throwsIOException/ new FileWriter( output.xml )/ writer = new XMLWriter( System.out, format );/ writer =

12、new XMLWriter( System.out, format );如何，DOM4JElementHandler 等。如DOM4J.DOM4J官方网站：(我老连不上) HYPERLINK / HYPERLINK /projects/dom4j Dom4j XML 及中文问题2004 9 27 20:21dom4jXMLXML文档，添加、修改、删除节点，以及格式化（美化）dom4j 的入门资料。 HYPERLINK /holen/ HYPERLINK /holen/ HYPERLINK mailto: dom4jXMLXML文档，添加、修改、删除节点，以及格式化（美化）dom4j 的入门资料

13、。1XML20011XML20017月发布1.5。dom4jJava Java 界，dom4j HYPERLINK /projects/dom4j dom4j1.5 13Mdom4j-1.5.zip 1.5.jarjaxen-1.1-beta-4.jar 文件，一般: 2XML 文档XML ?xmlversion=1.0encoding=UTF-!-Thisisatestfordom4j,holen,2004.9.11-XML 文档，场景是一个网上书店，有很多书，每本书有两个属性，一个3XML XML 文档,paramfilename return 返回操作结果0 表失败1 publicint

14、createXMLFile(String/* 返回操作结果0 表失败1 intreturnValue=/*intreturnValue=/* document Documentdocument=/* XML booksElementbooksElement=/* booksElement.addComment(Thisisatestfordom4j,holen,/* book ElementbookElement=/* show /* title ElementtitleElement=/* title /* bookbookElement=booksElement.addElement(bo

15、ok); titleElement=bookElement.addElement(title); titleElement.setText(Lucene Studing);bookElement=booksElement.addElement(book); titleElement= /* owner ElementownerElement=/* document XMLWriterwriter=newXMLWriter(newFileWriter(newFile(filename); /* 执行成功,1*/ returnValue = 1;catch(Exception ex) return

16、Documentdocument=XMLDocumentdocument=XML ElementbooksElement=XML Element 有几个重要的方法： 最后通过 XMLWriter 生成物理文件，默认生成的 XML 文件排版格式比较乱，可以通过 OutputFormat 类的 createCompactFormat()方法或 createPrettyPrint()方法格式化输出默认采createCompactFormat()方法，显示比较紧凑，这点将在后面详细谈到。holen.xml !-Thisisatestfordom4j,holen,2004.9.11-4XML 如果boo

17、k节点中show属性的内容为yes,则修改成no 把owner 项内容改为Tshinghua，并添加date 节点titleDom4jTutorials,XML 文件中内容,dom4j中如何添加节点,修改节点,paramfilename paramnewfilename return 返回操作结果0 表失败1 publicintModiXMLFile(Stringfilename,Stringnewfilename) int returnValue = 0;SAXReadersaxReader=new /* 修改内容之一: book show yes,no/* xpath Listlist=d

18、ocument.selectNodes(/books/book/showIteratoriter=Iteratoriter=修改内容之二: owner ownerdate节点,date 2004-09-11,date 节点添typelist=document.selectNodes(/books/owner); iter = list.iterator();ElementdateElement=ownerElement.addElement(date); /* 修改内容之三: titleDom4jTutorials,则删除该节点 list = document.selectNodes(/boo

19、ks/book);iter = list.iterator(); ElementbookElement=Element/* document XMLWriterwriter=newXMLWriter(newFileWriter(newFile(newfilename); /* 执行成功,1*/ returnValue = 1; return returnListlist=document.selectNodes(/books/book/show); list = document.selectNodes(/books/book);xpath5OutputFormat 类。XML 文档,para

20、mpublicintformatXMLFile(Stringfilename) int returnValue = 0;SAXReadersaxReader=newDocumentdocument=saxReader.read(newFile(filename); XMLWriter writer = null;/* 格式化输出,IE 浏览一样 OutputFormatformat=/* XML 编码 */ writer=newXMLWriter(newFileWriter(new/* 执行成功,1*/ returnValue = 1;catch(Exception ex) returnOut

21、putFormatformat=/* 执行成功,1*/ returnValue = 1;catch(Exception ex) returnOutputFormatformat=XMLWriterwriter=newXMLWriter(newFileWriter(newOutputFormat6packageimport import java.util.Iterator; import java.util.List;import import import org.dom4j.Element;import org.dom4j.io.SAXReader;import *authorHolen17:43 (4666) (2) 2 2007-08-132007-09-06FileWriter try OutputFormatformat=2007-08-132007-09-06FileWriter try OutputFormatformat=FileOutputStreamfos=new/writer=newXMLWriter(newFileWriter(xmlFile),format); writer = new XMLWriter(fos, form