java 使用DOM對XML文檔進行增刪改查操作

源代碼：

package com.zc.homeWork18;

import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class XMLWriter {

    private static String xmlPath = "src\\com\\zc\\homeWork18\\MyXml.xml";

    public static void getFamilyMemebers() {

    /*
         * 創建文件工廠實例
         */
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        // 如果創建的解析器在解析XML文檔時必須刪除元素內容中的空格，則爲true，否則爲false
        dbf.setIgnoringElementContentWhitespace(true);

        try {
            /*
             * 創建文件對象
             */
            DocumentBuilder db = dbf.newDocumentBuilder();// 創建解析器，解析XML文檔
            Document doc = db.parse(xmlPath); // 使用dom解析xml文件

            /*
             * 歷遍列表，進行XML文件的數據提取
             */
            // 根據節點名稱來獲取所有相關的節點
            NodeList sonlist = doc.getElementsByTagName("son");
            for (int i = 0; i < sonlist.getLength(); i++) // 循環處理對象
            {
                // 節點屬性的處理
                Element son = (Element) sonlist.item(i);
                // 循環節點son內的所有子節點
                for (Node node = son.getFirstChild(); node != null; node = node
                        .getNextSibling()) {
                    // 判斷是否爲元素節點
                    if (node.getNodeType() == Node.ELEMENT_NODE) {
                        String name = node.getNodeName();
                        String value = node.getFirstChild().getNodeValue();
                        System.out.println(name + " : " + value);
                    }
                }
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    // 修改
    public static void modifySon() {
        // 創建文件工廠實例
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setIgnoringElementContentWhitespace(true);
        try {
            // 從XML文檔中獲取DOM文檔實例
            DocumentBuilder db = dbf.newDocumentBuilder();
            // 獲取Document對象
            Document xmldoc = db.parse(xmlPath);

            // 獲取根節點
            Element root = xmldoc.getDocumentElement();
            // 定位id爲001的節點
            Element per = (Element) selectSingleNode("/father/son[@id='001']",
                    root);
            // 將age節點的內容更改爲28
            per.getElementsByTagName("age").item(0).setTextContent("28");
            // 保存
            TransformerFactory factory = TransformerFactory.newInstance();
            Transformer former = factory.newTransformer();
            former.transform(new DOMSource(xmldoc), new StreamResult(new File(
                    xmlPath)));
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    // 獲取目標節點，進行刪除，最後保存
    public static void discardSon() {

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setIgnoringElementContentWhitespace(true);

        try {

            DocumentBuilder db = dbf.newDocumentBuilder();
            Document xmldoc = db.parse(xmlPath);
            // 獲取根節點
            Element root = xmldoc.getDocumentElement();
            // 定位根節點中的id=002的節點
            Element son = (Element) selectSingleNode("/father/son[@id='002']",
                    root);
            // 刪除該節點
            root.removeChild(son);
            // 保存
            TransformerFactory factory = TransformerFactory.newInstance();
            Transformer former = factory.newTransformer();
            former.transform(new DOMSource(xmldoc), new StreamResult(new File(
                    xmlPath)));

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    // 新增節點
    public static void createSon() {
        // 創建文件工廠實例
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setIgnoringElementContentWhitespace(false);

        try {

            DocumentBuilder db = dbf.newDocumentBuilder();
            // 創建Document對象
            Document xmldoc = db.parse(xmlPath);
            // 獲取根節點
            Element root = xmldoc.getDocumentElement();
            // 創建節點son，設置對應的id爲004
            Element son = xmldoc.createElement("son");
            son.setAttribute("id", "004");
            // 創建節點name
            Element name = xmldoc.createElement("name");
            name.setTextContent("小兒子");
            son.appendChild(name);
            // 創建節點age
            Element age = xmldoc.createElement("age");
            age.setTextContent("0");
            son.appendChild(age);
            // 把son添加到根節點中
            root.appendChild(son);
            // 保存
            TransformerFactory factory = TransformerFactory.newInstance();
            Transformer former = factory.newTransformer();
            former.transform(new DOMSource(xmldoc), new StreamResult(new File(
                    xmlPath)));

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    // 修改節點信息
    public static Node selectSingleNode(String express, Element source) {
        Node result = null;
        //創建XPath工廠
        XPathFactory xpathFactory = XPathFactory.newInstance();
        //創建XPath對象
        XPath xpath = xpathFactory.newXPath();
        try {
            result = (Node) xpath.evaluate(express, source, XPathConstants.NODE);
            System.out.println(result);
        } catch (XPathExpressionException e) {
            System.out.println(e.getMessage());
        }

        return result;
    }

    // 打印
    public static void main(String[] args) {

        getFamilyMemebers();
        System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
        modifySon();
        System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
        System.out.println("修改數據");
        getFamilyMemebers();
        System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
        discardSon();
        System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
        System.out.println("刪除數據");
        getFamilyMemebers();
        System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
        createSon();
        System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
        System.out.println("添加數據");
        getFamilyMemebers();
    }
}

XML文件

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<father>
    <son id="001">
        <name>老大</name>
        <age>20</age>
    </son>
    <son id="002">
        <name>老二</name>
        <age>18</age>
    </son>
    <son id="003">
        <name>老三</name>
        <age>13</age>
    </son>

</father>