dom4j解析XML(二)
修改文档
这一节说明如何使用 dom4j API 修改示例 XML 文档 catalog.xml。
使用 SAXReader 解析 XML 文档 catalog.xml：
SAXReader saxReader = new SAXReader();
Document document = saxReader.read(inputXml);
SAXReader 包含在 org.dom4j.io 包中。
inputXml 是从 c:/catalog/catalog.xml 创建的 java.io.File。使用 XPath 表达式从 article 元素中获得 level 节点列表。如果 level 属性值是“Intermediate”则改为“Introductory”。
List list = document.selectNodes("//article/@level" );
Iterator iter=list.iterator();
while (iter.hasNext()){
Attribute attribute=(Attribute)iter.next();
if (attribute.getValue().equals( "Intermediate" ))
attribute.setValue("Introductory" );
}
获取 article 元素列表，从 article 元素中的 title 元素得到一个迭代器，并修改 title 元素的文本。
list = document.selectNodes("//article" );
iter=list.iterator();
while (iter.hasNext()){
Element element=(Element)iter.next();
Iterator iterator=element.elementIterator("title" );
while (iterator.hasNext()){
Element titleElement=(Element)iterator.next();
if (titleElement.getText().equals( "Java configuration with XML Schema" ))
titleElement.setText("Create flexible and extensible XML schema" );
}}
通过和 title 元素类似的过程修改 author 元素。
清单 4 所示的示例程序 Dom4JParser.java 用于把 catalog.xml 文档修改成 catalog-modified.xml 文档。
清单 4 . 用于修改 catalog.xml 的程序（Dom4Jparser.java）
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Attribute;
import java.util.List;
import java.util.Iterator;
import org.dom4j.io.XMLWriter;
import java.io.*;
import org.dom4j.DocumentException;
import org.dom4j.io.SAXReader;
public class Dom4JParser{
public void modifyDocument(File inputXml){
try {
SAXReader saxReader = new SAXReader();
Document document = saxReader.read(inputXml);
List list = document.selectNodes("//article/@level" );
Iterator iter=list.iterator();
while (iter.hasNext()){
Attribute attribute=(Attribute)iter.next();
if (attribute.getValue().equals( "Intermediate" ))
attribute.setValue("Introductory" );
}
list = document.selectNodes("//article/@date" );
iter=list.iterator();
while (iter.hasNext()){
Attribute attribute=(Attribute)iter.next();
if (attribute.getValue().equals( "December-2001" ))
attribute.setValue("October-2002" );
}
list = document.selectNodes("//article" );
iter=list.iterator();
while (iter.hasNext()){
Element element=(Element)iter.next();
Iterator iterator=element.elementIterator("title" );
while (iterator.hasNext()){
Element titleElement=(Element)iterator.next();
if (titleElement.getText().equals("Java configuration with XML
Schema"))
titleElement.setText("Create flexible and extensible XML schema" );
}
}
list = document.selectNodes("//article/author" );
iter=list.iterator();
while (iter.hasNext()){
Element element=(Element)iter.next();
Iterator iterator=element.elementIterator("firstname" );
while (iterator.hasNext()){
Element firstNameElement=(Element)iterator.next();
if (firstNameElement.getText().equals( "Marcello" ))
firstNameElement.setText("Ayesha" );
}
}
list = document.selectNodes("//article/author" );
iter=list.iterator();
while (iter.hasNext()){
Element element=(Element)iter.next();
Iterator iterator=element.elementIterator("lastname" );
while (iterator.hasNext()){
Element lastNameElement=(Element)iterator.next();
if (lastNameElement.getText().equals( "Vitaletti" ))
lastNameElement.setText("Malik" );
}
}
XMLWriter output = new XMLWriter(
new FileWriter( new File( "c:/catalog/catalog-modified.xml" ) ));
output.write( document );
output.close();
}
catch (DocumentException e)
{
System.out.println(e.getMessage());
}
catch (IOException e){
System.out.println(e.getMessage());
}
}
public static void main(String[] argv){
Dom4JParser dom4jParser=new Dom4JParser();
dom4jParser.modifyDocument(new File( "c:/catalog/catalog.xml" ));
}
}