在java中,使用JDOM怎么给XML添加一个元素节点和一个属性节点？

Element e = new Element("root")//根节点

Element ele = new Element("Class")//Class节点

ele.setAttribute("name","二年1班")//为class节点增加属性为name，值为二年一班的节点

import java.io.File

import java.io.FileNotFoundException

import java.io.FileOutputStream

import java.io.IOException

import org.w3c.dom.*

import org.xml.sax.SAXException

import javax.xml.parsers.*

import javax.xml.transform.*

import javax.xml.transform.dom.DOMSource

import javax.xml.transform.stream.*

import javax.xml.xpath.*

public class Test {

public static void main(String[] args) {

DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance()

Element theBook=null, theElem=null, root=null

try {

factory.setIgnoringElementContentWhitespace(true)

DocumentBuilder db=factory.newDocumentBuilder()

Document xmldoc=db.parse(new File("Test1.xml"))

root=xmldoc.getDocumentElement()

theBook=(Element) selectSingleNode("/books/book[name='哈里波特']", root)

System.out.println("--- 查询找《哈里波特》 ----")

Element nameNode=(Element)theBook.getElementsByTagName("price").item(0)

String name=nameNode.getFirstChild().getNodeValue()

System.out.println(name)

output(theBook)

System.out.println("=============selectSingleNode(books/book[name='哈里波特'], root)==================")

//--- 新建一本书开始 ----

theBook=xmldoc.createElement("book")

theElem=xmldoc.createElement("name")

theElem.setTextContent("新书")

theBook.appendChild(theElem)

theElem=xmldoc.createElement("price")

theElem.setTextContent("20")

theBook.appendChild(theElem)

theElem=xmldoc.createElement("memo")

theElem.setTextContent("新书的更好看。")

theBook.appendChild(theElem)

root.appendChild(theBook)

System.out.println("--- 新建一本书开始 ----")

output(xmldoc)

System.out.println("==============================")

//--- 新建一本书完成 ----

//--- 下面对《哈里波特》做一些修改。 ----

//--- 查询找《哈里波特》----

//--- 此时修改这本书的价格 -----

theBook.getElementsByTagName("price").item(0).setTextContent("15")//getElementsByTagName返回的是NodeList，所以要跟上item(0)。另外，getElementsByTagName("price")相当于xpath的".//price"。

System.out.println("--- 此时修改这本书的价格 ----")

output(theBook)

//--- 另外还想加一个属性id，值为B01 ----

theBook.setAttribute("id", "B01")

System.out.println("--- 另外还想加一个属性id，值为B01 ----")

output(theBook)

//--- 对《哈里波特》修改完成。 ----

//--- 要用id属性删除《三国演义》这本书 ----

theBook=(Element) selectSingleNode("/books/book[@id='B02']", root)

System.out.println("--- 要用id属性删除《三国演义》这本书 ----")

output(theBook)

theBook.getParentNode().removeChild(theBook)

System.out.println("--- 删除后的XML ----")

output(xmldoc)

//--- 再将所有价格低于10的书删除 ----

NodeList someBooks=selectNodes("/books/book[price<10]", root)

System.out.println("--- 再将所有价格低于10的书删除 ---")

System.out.println("--- 符合条件的书有　"+someBooks.getLength()+"本。 ---")

for(int i=0i<someBooks.getLength()i++) {

someBooks.item(i).getParentNode().removeChild(someBooks.item(i))

}

output(xmldoc)

saveXml("Test1_Edited.xml", xmldoc)

} catch (ParserConfigurationException e) {

e.printStackTrace()

} catch (SAXException e) {

e.printStackTrace()

} catch (IOException e) {

e.printStackTrace()

}

}

public static void output(Node node) {//将node的XML字符串输出到控制台

TransformerFactory transFactory=TransformerFactory.newInstance()

try {

Transformer transformer = transFactory.newTransformer()

transformer.setOutputProperty("encoding", "gb2312")

transformer.setOutputProperty("indent", "yes")

DOMSource source=new DOMSource()

source.setNode(node)

StreamResult result=new StreamResult()

result.setOutputStream(System.out)

transformer.transform(source, result)

} catch (TransformerConfigurationException e) {

e.printStackTrace()

} catch (TransformerException e) {

e.printStackTrace()

}

}

public static Node selectSingleNode(String express, Object source) {//查找节点，并返回第一个符合条件节点

Node result=null

XPathFactory xpathFactory=XPathFactory.newInstance()

XPath xpath=xpathFactory.newXPath()

try {

result=(Node) xpath.evaluate(express, source, XPathConstants.NODE)

} catch (XPathExpressionException e) {

e.printStackTrace()

}

return result

}

public static NodeList selectNodes(String express, Object source) {//查找节点，返回符合条件的节点集。

NodeList result=null

XPathFactory xpathFactory=XPathFactory.newInstance()

XPath xpath=xpathFactory.newXPath()

try {

result=(NodeList) xpath.evaluate(express, source, XPathConstants.NODESET)

} catch (XPathExpressionException e) {

e.printStackTrace()

}

return result

}

public static void saveXml(String fileName, Document doc) {//将Document输出到文件

TransformerFactory transFactory=TransformerFactory.newInstance()

try {

Transformer transformer = transFactory.newTransformer()

transformer.setOutputProperty("indent", "yes")

DOMSource source=new DOMSource()

source.setNode(doc)

StreamResult result=new StreamResult()

result.setOutputStream(new FileOutputStream(fileName))

transformer.transform(source, result)

} catch (TransformerConfigurationException e) {

e.printStackTrace()

} catch (TransformerException e) {

e.printStackTrace()

} catch (FileNotFoundException e) {

e.printStackTrace()

}

}

}

XML：

<?xml version="1.0" encoding="GBK"?>

<books>

<book>

<name>哈里波特</name>

<price>10</price>

<memo>这是一本很好看的书。</memo>

</book>

<book id="B02">

<name>三国演义</name>

<price>10</price>

<memo>四大名著之一。</memo>

</book>

<book id="B03">

<name>水浒</name>

<price>6</price>

<memo>四大名著之一。</memo>

</book>

<book id="B04">

<name>红楼</name>

<price>5</price>

<memo>四大名著之一。</memo>

</book>

</books>

---