java解析XML方法_dom4j

一.常用解析XML方法：
1. Xerces-J:
http://www.apache.org/dist/xml/xerces-j/
one of the most commonly used XML parser, from the Apache Project.
http://xml.apache.org/xerces-j/index.html
Xerces是由Apache组织所推动的一项XML文档解析开源项目,它目前有多种语言版本包括JAVA、C++、PERL、COM等。

2. JDom
JDOM是一种面向Java的读、写和操作XML文档的API。JDOM 与现行的SAX 和DOM标准兼容，为Java 程序员提供了一个简单、轻量的XML文档操作

方法。由于JDOM是专门为Java 程序员开发的，所以采用许多Java语言的优秀特性，比如方法重载、集合(Collections)和类映射(Reflection)

。
3. dom4j 这是很常用的。
Dom4j是一个易用的、开源的库，用于XML，XPath和XSLT。它应用于Java平台，采用了Java集合框架并完全支持DOM，SAX和JAXP。

二.下面以dom4j为例：


package xml;


import java.io.FileWriter;


import java.io.IOException;


import java.util.Iterator;




import org.dom4j.Document;


import org.dom4j.DocumentException;


import org.dom4j.DocumentHelper;


import org.dom4j.Element;


import org.dom4j.io.OutputFormat;


import org.dom4j.io.SAXReader;


import org.dom4j.io.XMLWriter;






public class TestXML ...{


//创建XML文档




public static 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;


}


//将文档内容输出到文件或控制台




public static void write(Document document) throws IOException ...{




// lets write to a file


XMLWriter writer = new XMLWriter(


new FileWriter( "output.xml" )


);


writer.write( document );


writer.close();






// Pretty print the document to System.out


OutputFormat format = OutputFormat.createPrettyPrint();


writer = new XMLWriter( System.out, format );


writer.write( document );




// Compact format to System.out


format = OutputFormat.createCompactFormat();


writer = new XMLWriter( System.out, format );


writer.write( document );


}


//解析XML文件成Document ,url为文件路径




public static Document parse(String url) throws DocumentException ...{


SAXReader reader = new SAXReader();


Document document = reader.read(url);


return document;


}


//read Docment内容




public static void read(Document document) throws DocumentException ...{




Element root = document.getRootElement();




// 从XML的根结点开始遍历




for ( Iterator i = root.elementIterator(); i.hasNext(); ) ...{


Element element = (Element) i.next();


System.out.println(element.getName()+":"+element.getText());


}






/**//* // iterate through child elements of root with element name "foo"


for ( Iterator i = root.elementIterator( "foo" ); i.hasNext(); ) {


Element foo = (Element) i.next();


// do something


}




// iterate through attributes of root


for ( Iterator i = root.attributeIterator(); i.hasNext(); ) {


Attribute attribute = (Attribute) i.next();


// do something


}*/


}




//将document转化为String




public static String XmlToString(Document document)...{


return document.asXML();


}




//将document转化为String




public static Document StringToDocument(String text)...{




try ...{


return DocumentHelper.parseText(text);




} catch (DocumentException e) ...{


// TODO Auto-generated catch block


e.printStackTrace();


return null;


}


}




public static void main(String[] args) throws IOException, DocumentException ...{


// write(parse("E:/WebService/XFire/example/XFire/output.xml"));


String str="<?xml version='1.0' encoding='utf-16'?> "+


"<CurrentWeather>"+


"<Location>Shanghai / Hongqiao, China (ZSSS) 31-10N 121-26E 3M</Location>"+


"<Time>Aug 22, 2007 - 09:00 PM EDT / 2007.08.23 0100 UTC</Time>"+


"<Wind> from the ESE (110 degrees) at 7 MPH (6 KT) (direction variable):0</Wind>"+


"<Visibility> 4 mile(s):0</Visibility>"+


"<SkyConditions> mostly clear</SkyConditions>"+


"<Temperature> 87 F (31 C)</Temperature>"+


"<DewPoint> 78 F (26 C)</DewPoint>"+


"<RelativeHumidity> 74%</RelativeHumidity>"+


"<Pressure> 29.77 in. Hg (1008 hPa)</Pressure>"+


"<Status>Success</Status>"+


"</CurrentWeather>";


write(StringToDocument(str));


}










}