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，則為true，否則為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()) {
          // 判斷是否為元素節點
          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為001的節點
      Element per = (Element) selectSingleNode("/father/son[@id='001']",
          root);
      // 將age節點的內容更改為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，最后保存
  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為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 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>