复制代码 代码如下:

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=0;i<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();
        }  
    }
}

复制代码 代码如下:

<?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>