sitinspring(如坐春風(fēng))原創(chuàng),轉(zhuǎn)載請(qǐng)注明作者及出處.
要使用dom4j讀寫XML文檔,需要先下載dom4j包,dom4j官方網(wǎng)站在 http://www.dom4j.org/
目前最新dom4j包下載地址:http://nchc.dl.sourceforge.net/sourceforge/dom4j/dom4j-1.6.1.zip
解開(kāi)后有兩個(gè)包,僅操作XML文檔的話把dom4j-1.6.1.jar加入工程就可以了,如果需要使用XPath的話還需要加入包jaxen-1.1-beta-7.jar.
以下是相關(guān)操作:
一.Document對(duì)象相關(guān)
1.讀取XML文件,獲得document對(duì)象.
SAXReader reader = new SAXReader();
Document document = reader.read(new File("input.xml")); String text = "<members></members>";
Document document = DocumentHelper.parseText(text);
3.主動(dòng)創(chuàng)建document對(duì)象.
Document document = DocumentHelper.createDocument();
Element root = document.addElement("members");// 創(chuàng)建根節(jié)點(diǎn)
二.節(jié)點(diǎn)相關(guān)
1.獲取文檔的根節(jié)點(diǎn).
Element rootElm = document.getRootElement();
2.取得某節(jié)點(diǎn)的單個(gè)子節(jié)點(diǎn).
Element memberElm=root.element("member");// "member"是節(jié)點(diǎn)名
3.取得節(jié)點(diǎn)的文字
String text=memberElm.getText();
也可以用:
String text=root.elementText("name");
這個(gè)是取得根節(jié)點(diǎn)下的name字節(jié)點(diǎn)的文字.
4.取得某節(jié)點(diǎn)下名為"member"的所有字節(jié)點(diǎn)并進(jìn)行遍歷.
List nodes = rootElm.elements("member");
for (Iterator it = nodes.iterator(); it.hasNext();) 
{
Element elm = (Element) it.next();
// do something
}
5.對(duì)某節(jié)點(diǎn)下的所有子節(jié)點(diǎn)進(jìn)行遍歷.
for(Iterator it=root.elementIterator();it.hasNext();){
Element element = (Element) it.next();
// do something
}
6.在某節(jié)點(diǎn)下添加子節(jié)點(diǎn).
Element ageElm = newMemberElm.addElement("age");
7.設(shè)置節(jié)點(diǎn)文字.
ageElm.setText("29");
8.刪除某節(jié)點(diǎn).
parentElm.remove(childElm);// childElm是待刪除的節(jié)點(diǎn),parentElm是其父節(jié)點(diǎn)
9.添加一個(gè)CDATA節(jié)點(diǎn).
Element contentElm = infoElm.addElement("content");
contentElm.addCDATA(diary.getContent());
三.屬性相關(guān).
1.取得某節(jié)點(diǎn)下的某屬性
Element root=document.getRootElement();
Attribute attribute=root.attribute("size");// 屬性名name
2.取得屬性的文字
String text=attribute.getText();
也可以用:
String text2=root.element("name").attributeValue("firstname");
這個(gè)是取得根節(jié)點(diǎn)下name字節(jié)點(diǎn)的屬性firstname的值.
3.遍歷某節(jié)點(diǎn)的所有屬性
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.設(shè)置某節(jié)點(diǎn)的屬性和文字.
newMemberElm.addAttribute("name", "sitinspring");
5.設(shè)置屬性的文字
Attribute attribute=root.attribute("name");
attribute.setText("sitinspring");
6.刪除某屬性
Attribute attribute=root.attribute("size");// 屬性名name
root.remove(attribute);
四.將文檔寫入XML文件.
1.文檔中全為英文,不設(shè)置編碼,直接寫入的形式.
XMLWriter writer = new XMLWriter(new FileWriter("output.xml"));
writer.write(document);
writer.close();
2.文檔中含有中文,設(shè)置編碼格式寫入的形式.
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("GBK"); // 指定XML編碼
XMLWriter writer = new XMLWriter(new FileWriter("output.xml"),format);
writer.write(document);
writer.close();
五.字符串與XML的轉(zhuǎn)換
1.將字符串轉(zhuǎn)化為XML
String text = "<members> <member>sitinspring</member> </members>";
Document document = DocumentHelper.parseText(text);
2.將文檔或節(jié)點(diǎn)的XML轉(zhuǎn)化為字符串.
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快速找到節(jié)點(diǎn).
讀取的XML文檔示例
<?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快速找到節(jié)點(diǎn)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();
}
}