要使用dom4j读写XML文档,需要先下载dom4j包,dom4j官方网站在 http://www.dom4j.org/目前最新dom4j包下载地址:http://nchc.dl.sourceforge.net/sourceforge/dom4j/dom4j-1.6.1.zip
解开后有两个包,仅操作XML文档的话把dom4j-1.6.1.jar加入工程就可以了,如果需要使用XPath的话还需要加入包jaxen-1.1-beta-7.jar.
以下是相关操作:
一.Document对象相关
1.读取XML文件,获得document对象. SAXReader reader = new SAXReader(); Document document = reader.read(new File("input.xml"));
2.解析XML形式的文本,得到document对象. String text = "<members></members>"; Document document = DocumentHelper.parseText(text);3.主动创建document对象. Document document = DocumentHelper.createDocument(); Element root = document.addElement("members");// 创建根节点二.节点相关
1.获取文档的根节点.Element rootElm = document.getRootElement();2.取得某节点的单个子节点.Element memberElm=root.element("member");// "member"是节点名3.取得节点的文字String text=memberElm.getText();也可以用:String text=root.elementText("name");这个是取得根节点下的name字节点的文字.
4.取得某节点下名为"member"的所有字节点并进行遍历.List nodes = rootElm.elements("member");
for (Iterator it = nodes.iterator(); it.hasNext();) { Element elm = (Element) it.next(); // do something}5.对某节点下的所有子节点进行遍历. for(Iterator it=root.elementIterator();it.hasNext();){ Element element = (Element) it.next(); // do something }6.在某节点下添加子节点.Element ageElm = newMemberElm.addElement("age");7.设置节点文字.ageElm.setText("29");8.删除某节点.parentElm.remove(childElm);// childElm是待删除的节点,parentElm是其父节点三.属性相关.1.取得某节点下的某属性 Element root=document.getRootElement(); Attribute attribute=root.attribute("size");// 属性名name2.取得属性的文字 String text=attribute.getText();也可以用:String text2=root.element("name").attributeValue("firstname");这个是取得根节点下name字节点的属性firstname的值.
3.遍历某节点的所有属性 Element root=document.getRootElement(); for(Iterator it=root.attributeIterator();it.hasNext();){ Attribute attribute = (Attribute) it.next(); String text=attribute.getText(); System.out.println(text); }4.设置某节点的属性和文字.newMemberElm.addAttribute("name", "sitinspring");5.设置属性的文字 Attribute attribute=root.attribute("name"); attribute.setText("sitinspring");6.删除某属性 Attribute attribute=root.attribute("size");// 属性名name root.remove(attribute);四.将文档写入XML文件.1.文档中全为英文,不设置编码,直接写入的形式.XMLWriter writer = new XMLWriter(new FileWriter("output.xml"));writer.write(document);writer.close();2.文档中含有中文,设置编码格式写入的形式. OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding("GBK"); // 指定XML编码 XMLWriter writer = new XMLWriter(new FileWriter("output.xml"),format); writer.write(document); writer.close();五.字符串与XML的转换1.将字符串转化为XMLString text = "<members> <member>sitinspring</member> </members>";Document document = DocumentHelper.parseText(text);2.将文档或节点的XML转化为字符串. SAXReader reader = new SAXReader(); Document document = reader.read(new File("input.xml")); Element root=document.getRootElement(); String docXmlText=document.asXML(); String rootXmlText=root.asXML(); Element memberElm=root.element("member"); String memberXmlText=memberElm.asXML();六.使用XPath快速找到节点.读取的XML文档示例<?xml version="1.0" encoding="UTF-8"?><projectDescription> <name>MemberManagement</name> <comment></comment> <projects> <project>PRJ1</project> <project>PRJ2</project> <project>PRJ3</project> <project>PRJ4</project> </projects> <buildSpec> <buildCommand> <name>org.eclipse.jdt.core.javabuilder</name> <arguments> </arguments> </buildCommand> </buildSpec> <natures> <nature>org.eclipse.jdt.core.javanature</nature> </natures></projectDescription>
使用XPath快速找到节点project. public static void main(String[] args){ SAXReader reader = new SAXReader(); try{ Document doc = reader.read(new File("sample.xml")); List projects=doc.selectNodes("/projectDescription/projects/project"); Iterator it=projects.iterator(); while(it.hasNext()){ Element elm=(Element)it.next(); System.out.println(elm.getText()); } } catch(Exception ex){ ex.printStackTrace(); }
package com.stz;
import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.DocumentHelper;
import org.dom4j.Element;import org.dom4j.io.SAXReader;
import java.io.File;
import java.util.Iterator;import java.util.List;
public class TestDate {
public static void main(String[]args){ String xml="<?xml version=\"1.0\" encoding=\"utf-8\"?>"+ "<students>"+ " <student id=\"1\">"+ " <name>stz</name>"+ " <age>23</age>"+ "</student>"+ "<student id=\"2\">"+ "<name>rhl</name>"+ "<age>23</age>"+ "</student>"+ "<student id=\"3\">"+ " <name>tom</name>"+ " <age>23</age>"+ "</student>"+ "</students>"; try { Document document=DocumentHelper.parseText(xml); Element root=document.getRootElement(); //System.out.println(ele.e); //List nodes=root.elements("student"); //System.out.println(root.getName()); //root.elementIterator(); List nodes=document.selectNodes("/students/student");
for (Iterator it = nodes.iterator(); it.hasNext();) { Element elm = (Element) it.next(); System.out.println("id:"+elm.attributeValue("id")); System.out.println(elm.getName()); Element eles=elm.element("name"); System.out.println(eles.getText()); Element elea=elm.element("age"); System.out.println(elea.getText()); }
} catch (DocumentException e) { // TODO Auto-generated catch block e.printStackTrace(); }
}}
转载于:https://www.cnblogs.com/SZ2015/p/4579936.html
相关资源：数据结构—成绩单生成器