基于Java的文档对象模型.doc

四、JDOM1简介JDOM = Java-based document object model = Java-based DOM = 基于Java的文档对象模型 = 基于Java的DOMJDOM是Jason Hunter与Brett McLaughlin于2000年春建立的一个开源项目（/），它是一个基于Java的对象模型，与DOM一样也采用树状结构，能使读取、操作和写入XML文档，但比DOM更容易、更高效。已经推出的正式版本有JDOM 1.0（2004.9.9）和JDOM 1.1（2007.11.13，3.37MB）。JDOM已于2001年2月26日被Sun公司主持的JCP (Java Community Process，Java社团过程) 批准为JSR (Java Specification Request，Java规范需求) 标准 (JSR-102)。等将来成为正式的JCP标准后，JDOM可能会成为JAXP的一部分（目前的JAXP含有DOM、SAX和TrAX），不过JSR-102至今仍未获正式批准。1）DOM存在的问题DOM存在如下4个设计缺陷和局限：l DOM要与浏览器已有的设计欠佳的对象模型兼容，使得DOM的模型不够完美；l DOM是委员会中微软、网景等厂家的一个妥协方案，使得DOM的API不理想；l DOM是用IDL定义的语言中立的API，只能使用所有语言（包括非完全面向对象的脚本语言JavaScript和VBScript）都支持的特性，使得DOM不能充分发挥Java的优势；l DOM需同时处理XML和HTML（不仅是XHTML，还包括非良构的传统HTML），使得DOM臃肿低效。2）JDOM模型JDOM用10个基本类来表示XML文档中不同类型的节点（DOM用12种节点接口表示，多出的两种节点是：文档片段DocumentFragment和记号Notation），其中最主要的是元素类Element，它在JDOM中处于中心的地位。JDOM的文档类Document类似于DOM的根节点接口，它和元素类Element，都是Parent接口的实现。JDOM中定义了一个内容类Content，有一点像DTD中的PCDATA或参数实体，可以是任何XML文档中的逻辑语义文本内容，从它派生的Comment、DocType、Element、EntityRef、ProcessingInstruction、Text等子类对象，都可以作为Document和Element类的内容节点。只有名域、属性和CDATA节点不是Content的派生类。JDOM中的Content类的作用似DOM中的节点接口Node。下面是JDOM核心类（位于org.jdom包中）的UML模型（其中的左边部分，可与XML文档结构进行比较）：DocumentDocTypeElementAttributeTextCommentProcessingInstructionNamespaceCDATAEntityRefContentJDOMFactoryDefaultJDOMFactoryUncheckedJDOMFactoryParentJDOMExceptionJDOMExceptionIllegalAddExceptionjava.lang.IllegalArgumentExceptionIllegalDataExceptionIllegalNameExceptionIllegalTargetException图例：类、 接口、 派生或实现org.jdom包中的JDOM核心类在JDOM中，处理XML文档的工作主要由org.jdom包中的JDOM核心类来完成，其中最重要的是起中心作用的Element类。与DOM不同的是，Element类提供了丰富的方法，可以通过Element对象，非常方便地直接操作其属性、文本内容和子元素等。org.jdom.filter包中的过滤类，在文档处理过程中，帮助选择要处理的内容节点（集）。该包中有1个接口和3个类，下面是它们之间的实现或派生关系的层次结构图：Filter接口AbstractFilter类ContentFilter类ElementFilter类org.jdom.filter包中的过滤类注意，在JDOM中，并没有专门的表示元素节点集和属性节点集的接口或类，而是直接使用了Java的列表泛型（Generic Type）接口java.util.List。还可以使用同一包中的迭代器泛型接口Iterator或ListIterator，来在所获得的元素或属性节点集中进行遍历。虽然可以由JDOM核心类，来直接生成新的XML文档的JDOM表示。但是在JDOM中，对XML文档的读取、分析和验证工作，都由JDOM输入包org.jdom.input中的几个创建器类来完成。该包中含有两个创建器类、两个处理器类和一个异常类。参见下图：java.lang.ObjectDOMBuilderSAXBuilderBuilderErrorHandlerSAXHandlerorg.xml.sax.helpers.DefaultHandlerJDOMParseExceptionorg.jdom.JDOMExceptionorg.jdom.input包中的创建类等JDOM的输入对象非常广泛，可以是XML文档源文件，也可以是内存中直接创建的新XML文档，还可以是DOM文档树。JDOM的输出对象也很广泛，可以是XML文档文件、SAX处理器、以及DOM文档树。JDOM的输出是由org.jdom.output包中的类来完成的，其中的两个格式类，可以用来指定输出的具体格式要求。参见下图：java.lang.ObjectDOMOutputterSAXOutputterXMLOutputterJDOMLocatororg.xml.sax.helpers.LocatorImplEscapeStrategyFormatFormat.TextModeorg.jdom.output包中的类XML文档SAXBuilderDOMBuilderDOM节点DOMOutputterXMLOutputterSAXOutputterJDOM文档Format直接创建JDOM中的输入与输出3）JDOM包JDOM 1.0/1.1中含有如下7个包：l org.jdom含表示XML文档部件的类（14个类和6个异常）l org.jdom.adapters含面向各种DOM实现的接口类（1个接口和7个类）l org.jdom.filter含过滤文档节点的类（1个接口和3个类）l org.jdom.input含从不同来源创建JDOM文档的类（1个接口和4个类）l org.jdom.output含输出JDOM文档到不同目标的类（1个接口和7个类，其中XMLOutputter.NamespaceStack类是1.1版新增加的）l org.jdom.transform含基于JAXP之TrAX的帮助转换的类（3个类和1个异常）l org.jdom.xpath含在JDOM内提供对XPath支持的类（1个类）共有4个接口、39个类和7个异常（类），合计50个接口和类。下面是这些包、类和接口的层次结构：（参见JDOM 1.1的API文档/docs/apidocs/）Hierarchy For All PackagesPackage Hierarchies: org.jdom, org.jdom.adapters, org.jdom.filter, org.jdom.input, org.jdom.output, org.jdom.transform, org.jdom.xpathClass Hierarchy o java.lang.Object o org.jdom.adapters.AbstractDOMAdapter (implements org.jdom.adapters.DOMAdapter) o org.jdom.adapters.CrimsonDOMAdapter o org.jdom.adapters.JAXPDOMAdapter o org.jdom.adapters.OracleV1DOMAdapter o org.jdom.adapters.OracleV2DOMAdapter o org.jdom.adapters.XercesDOMAdapter o org.jdom.adapters.XML4JDOMAdaptero org.jdom.filter.AbstractFilter (implements org.jdom.filter.Filter) o org.jdom.filter.ContentFilter o org.jdom.filter.ElementFiltero org.jdom.Attribute (implements java.lang.Cloneable, java.io.Serializable) o org.jdom.input.BuilderErrorHandler (implements org.xml.sax.ErrorHandler) o org.jdom.Content (implements java.lang.Cloneable, java.io.Serializable) o org.jdom.Comment o org.jdom.DocType o org.jdom.Element (implements org.jdom.Parent) o org.jdom.EntityRef o org.jdom.ProcessingInstruction o org.jdom.Text o org.jdom.CDATAo org.xml.sax.helpers.DefaultHandler (implements org.xml.sax.ContentHandler, org.xml.sax.DTDHandler, org.xml.sax.EntityResolver, org.xml.sax.ErrorHandler) o org.jdom.input.SAXHandler (implements org.xml.sax.ext.DeclHandler, org.xml.sax.DTDHandler, org.xml.sax.ext.LexicalHandler) o org.jdom.DefaultJDOMFactory (implements org.jdom.JDOMFactory) o org.jdom.Document (implements org.jdom.Parent) o org.jdom.input.DOMBuilder o org.jdom.output.DOMOutputter o org.jdom.output.Format (implements java.lang.Cloneable) o org.jdom.output.Format.TextMode o org.xml.sax.helpers.LocatorImpl (implements org.xml.sax.Locator) o org.jdom.output.JDOMLocatoro org.jdom.Namespace o org.jdom.input.SAXBuilder o org.jdom.output.SAXOutputter o javax.xml.transform.sax.SAXResult (implements javax.xml.transform.Result) o org.jdom.transform.JDOMResulto javax.xml.transform.sax.SAXSource (implements javax.xml.transform.Source) o org.jdom.transform.JDOMSourceo java.lang.Throwable (implements java.io.Serializable) o java.lang.Exception o org.jdom.JDOMException o org.jdom.DataConversionException o org.jdom.input.JDOMParseException o org.jdom.transform.XSLTransformExceptiono java.lang.RuntimeException o java.lang.IllegalArgumentException o org.jdom.IllegalAddException o org.jdom.IllegalDataException o org.jdom.IllegalNameException o org.jdom.IllegalTargetExceptiono org.jdom.UncheckedJDOMFactory (implements org.jdom.JDOMFactory) o org.jdom.Verifier o org.jdom.output.XMLOutputter (implements java.lang.Cloneable) o org.jdom.output.XMLOutputter.NamespaceStack o org.jdom.xpath.XPath (implements java.io.Serializable) o org.jdom.transform.XSLTransformerInterface Hierarchy o java.lang.Cloneable o org.jdom.Parent (also extends java.io.Serializable) o org.jdom.adapters.DOMAdapter o org.jdom.output.EscapeStrategy o org.jdom.JDOMFactory o java.io.Serializable o org.jdom.filter.Filter o org.jdom.Parent (also extends java.lang.Cloneable) 4）使用下载并解压安装JDOM 1.1（/dist/binary/jdom-1.1.zip，3.37MB），为了使你的Java程序能够使用JDOM，可以设置类路径：SET CLASSPATH 解压安装路径的根目录下的Build子目录（含jdom.jar库文件）也可以将jdom.jar库文件拷进你的JDK目录中的jrelibext子目录中。下面各例，继续采用Windows XP环境，使用最新的JDK 1.6.0_06版（2008年3月25日），仍利用TextPad 4.7.3进行编辑和测试。2类与接口1）SAXBuilder类package org.jdom.input;import java.io.*;import java.lang.reflect.*;import .*;import java.util.*;import org.jdom.*;import org.xml.sax.*;import org.xml.sax.helpers.XMLReaderFactory;public class SAXBuilder public SAXBuilder(); public SAXBuilder(boolean validate); public SAXBuilder(String saxDriverClass); public SAXBuilder(String saxDriverClass, boolean validate); public String getDriverClass(); public JDOMFactory getFactory(); public void setFactory(JDOMFactory factory); public boolean getValidation(); public void setValidation(boolean validate); public ErrorHandler getErrorHandler(); public void setErrorHandler(ErrorHandler errorHandler); public EntityResolver getEntityResolver(); public void setEntityResolver(EntityResolver entityResolver); public DTDHandler getDTDHandler(); public void setDTDHandler(DTDHandler dtdHandler); public XMLFilter getXMLFilter(); public void setXMLFilter(XMLFilter xmlFilter); public boolean getIgnoringElementContentWhitespace();public void setIgnoringElementContentWhitespace(boolean ignoringWhite);public boolean getIgnoringBoundaryWhitespace(); / 1.1版新增加的public void setIgnoringBoundaryWhitespace(boolean ignoringBoundaryWhite); / 1.1版新增加的 public boolean getReuseParser(); public void setReuseParser(boolean reuseParser); public void setFeature(String name, boolean value); public void setProperty(String name, Object value);public Document build(InputSource in) throws JDOMException, IOException;protected SAXHandler createContentHandler();protected void configureContentHandler(SAXHandler contentHandler);protected XMLReader createParser() throws JDOMException;protected void configureParser(XMLReader parser, SAXHandler contentHandler) throws JDOMException; public Document build(InputStream in) throws JDOMException, IOException; public Document build(File file) throws JDOMException, IOException; public Document build(URL url) throws JDOMException, IOException; public Document build(InputStream in, String systemId) throws JDOMException, IOException; public Document build(Reader characterStream) throws JDOMException, IOException;public Document build(Reader characterStream, String systemId) throws JDOMException, IOException; public Document build(String systemId) throws JDOMException, IOException; public boolean getExpandEntities(); public void setExpandEntities(boolean expand);2）XMLOutputter类package org.jdom.output;import java.io.*;import java.util.*;import javax.xml.transform.Result;import org.jdom.*;public class XMLOutputter implements Cloneable public XMLOutputter(); public XMLOutputter(Format format); public XMLOutputter(XMLOutputter that); public void setFormat(Format newFormat); public Format getFormat(); public void output(Document doc, OutputStream out) throws IOException; public void output(DocType doctype, OutputStream out) throws IOException; public void output(Element element, OutputStream out) throws IOException; public void outputElementContent(Element element, OutputStream out) throws IOException; public void output(List list, OutputStream out) throws IOException; public void output(CDATA cdata, OutputStream out) throws IOException; public void output(Text text, OutputStream out) throws IOException; public void output(Comment comment, OutputStream out) throws IOException; public void output(ProcessingInstruction pi, OutputStream out) throws IOException; public void output(EntityRef entity, OutputStream out) throws IOException; public void output(Document doc, Writer out) throws IOException; public void output(DocType doctype, Writer out) throws IOException; public void output(Element element, Writer out) throws IOException; public void outputElementContent(Element element, Writer out) throws IOException; public void output(List list, Writer out) throws IOException; public void output(CDATA cdata, Writer out) throws IOException; public void output(Text text, Writer out) throws IOException; public void output(Comment comment, Writer out) throws IOException; public void output(ProcessingInstruction pi, Writer out) throws IOException; public void output(EntityRef entity, Writer out) throws IOException; public String outputString(Document doc); public String outputString(DocType doctype); public String outputString(Element element); public String outputString(List list); public String outputString(CDATA cdata); public String outputString(Text text); public String outputString(Comment comment); public String outputString(ProcessingInstruction pi); public String outputString(EntityRef entity); public String escapeAttributeEntities(String str); public String escapeElementEntities(String str); public Object clone();3）Format类package org.jdom.output;import java.lang.reflect.Method;public class Format implements Cloneable public static Format getRawFormat(); public static Format getPrettyFormat(); public static Format getCompactFormat(); private static final String STANDARD_INDENT = ; private static final String STANDARD_LINE_SEPARATOR = rn; private static final String STANDARD_ENCODING = UTF-8; String indent = null; String lineSeparator = STANDARD_LINE_SEPARATOR; String encoding = STANDARD_ENCODING; boolean omitDeclaration = false; boolean omitEncoding = false; boolean expandEmptyElements = false; boolean ignoreTrAXEscapingPIs = false; TextMode mode = TextMode.PRESERVE; EscapeStrategy escapeStrategy = new DefaultEscapeStrategy(encoding); public Format setEscapeStrategy(EscapeStrategy strategy); public EscapeStrategy getEscapeStrategy(); public Format setLineSeparator(String separator); public String getLineSeparator(); public Format setOmitEncoding(boolean omitEncoding); public boolean getOmitEncoding(); public Format setOmitDeclaration(boolean omitDeclaration); public boolean getOmitDeclaration(); public Format setExpandEmptyElements(boolean expandEmptyElements); public boolean getExpandEmptyElements(); public void setIgnoreTrAXEscapingPIs(boolean ignoreTrAXEscapingPIs); public boolean getIgnoreTrAXEscapingPIs(); public Format setTextMode(Format.TextMode mode); public Format.TextMode getTextMode(); public Format setIndent(String indent); public String getIndent(); public Format setEncoding(String encoding); public String getEncoding(); protected Object clone(); class DefaultEscapeStrategy implements EscapeStrategy Object encoder; Method canEncode; public DefaultEscapeStrategy(String encoding); public boolean shouldEscape(char ch); public static class TextMode public static final TextMode PRESERVE; public static final TextMode TRIM; public static final TextMode NORMALIZE; public static final TextMode TRIM_FULL_WHITE; public String toString(); 4）Document类package org.jdom;import java.util.*;import org.jdom.filter.*;public class Document implements Parent ContentList content; protected String baseURI; public Document(); public Document(Element rootElement, DocType docType, String baseURI); public Document(Element rootElement, DocType docType); public Document(Element rootElement); public Document(List content); public int getContentSize(); public int indexOf(Content child); public boolean hasRootElement(); public Element getRootElement(); public Document setRootElement(Element rootElement); public Element detachRootElement(); public DocType getDocType(); public Document setDocType(DocType docType); public Document addContent(Content child); public Document addContent(Collection c); public Document addContent(int index, Content child); public Document addContent(int index, Collection c); public List cloneContent(); public Content getContent(int index); public List getContent(); public List getContent(Filter filter); public List removeContent(); public List removeContent(Filter filter); public Document setContent(Collection newContent); public final void setBaseURI(String uri); public final String getBaseURI(); public Document setContent(int index, Content child); public Document setContent(int index, Collection collection); public boolean removeContent(Content child); public Content removeContent(int index); public Document setContent(Content child); public String toString(); public final boolean equals(Object ob); public final int hashCode(); public Object clone(); public Iterator getDescendants(); public Iterator getDescendants(Filter filter); public Parent getParent(); public Document getDocument(); public void setProperty(String id, Object value); public Object getProperty(String id);6）Iterator泛型接口package java.util;public interface Iterator boolean hasNext(); E next(); void remove();7）Element类package org.jdom;import java.io.*;import java.util.*;import org.jdom.filter.*;public class Element extends Content implements Parent AttributeList attributes; ContentList content; public Element(String name, Namespace namespace); public Element(String name); public Element(String name, String uri); public Element(String name, String prefix, String uri); public String getName(); public Element setName(String name); public Namespace getNamespace(); public Element setNamespace(Namespace namespace); public String getNamespacePrefix(); public String getNamespaceURI(); public Namespace getNamespace(String prefix); public String getQualifiedName(); public void addNamespaceDeclaration(Namespace additional); public void removeNamespaceDeclaration(Namespace additionalNamespace); public List getAdditionalNamespaces(); public String getValue(); public boolean isRootElement(); public int getContentSize(); public int indexOf(Content child); public String getText(); public String getTextTrim(); public String getTextNormalize(); public String getChildText(String name); public String getChildTextTrim(String name); public String getChildTextNormalize(String name); public String getChildText(String name, Namespace ns); public String getChildTextTrim(String name, Namespace ns); public String getChildTextNormalize(String name, Namespace ns); public Element setText(String text); public List getContent(); public List getContent(Filter filter); public List removeContent(); public List removeContent(Filter filter); public Element setContent(Collection newContent); public Element setContent(int index, Content child); public Parent se