java使用DOM4J对XML文件进行增删改查操作 java使用DOM4J对XML文件进行增删改查操作
zc2274460 人气:0源代码:
DOM4j.java
package com.zc.homeWork19; import java.io.FileWriter; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.io.SAXReader; import org.dom4j.io.XMLWriter; import com.zc.homeWork19.Book; public class DOM4j { public static void main(String args[]) throws Exception { /** * 第一步,得到document对象。 */ Document document = getDocument(); /** * 第二步,修改得到的document对象 */ /** * 首先,读取功能 */ List<Book> books = readAllElementsFromXMLDocument(document); traverseBooks(books); /** * 其次,修改功能 修改内容:将id为b002的元素的title改为Java Core,Price改为100.01 */ ModifyInformationOfXMLDocument(document); /** * 再者:实现删除功能 删除内容:删除掉id为book1的元素内容。 */ deleteInformationOfXMLDocument(document); /** * 最后:实现添加i新元素功能 添加内容:id为book3,title内容为:凤姐玉照,price内容为10000.00 */ addNewBookToXMLDocument(document); /** * 第三步:将得到的document对象持久化保存到硬盘(XML) */ writeToNewXMLDocument(document); } /** * 实现了添加新节点:book的功能 * * @param document */ private static void addNewBookToXMLDocument(Document document) { Element root = document.getRootElement(); Element newBook = root.addElement("book"); newBook.addAttribute("id", "book3"); Element title = newBook.addElement("title"); title.setText("凤姐玉照"); Element price = newBook.addElement("price"); price.setText("10000.01"); } /** * 该方法实现了使用dom4j的删除元素的功能 * * @param document */ private static void deleteInformationOfXMLDocument(Document document) { Element root = document.getRootElement(); for (Iterator it = root.elementIterator(); it.hasNext();) { Element book = (Element) it.next(); String id = book.attributeValue("id"); if ("book1".equals(id)) { Element parent = book.getParent(); parent.remove(book); } } } /** * 该方法的作用是修改document中的内容 将id为b002的元素的title改为Java Core,Price改为100.01 * * @param document */ private static void ModifyInformationOfXMLDocument(Document document) { Element root = document.getRootElement(); List books = root.elements(); for (int i = 0; i < books.size(); i++) { Element book = (Element) books.get(i); if ("book2".equals(book.attributeValue("id"))) { for (Iterator it = book.elementIterator(); it.hasNext();) { Element node = (Element) it.next(); String type = node.getName(); if ("title".equals(type)) { node.setText("JAVA Core"); } if ("price".equals(type)) { node.setText("100.01"); } } } } try { writeToNewXMLDocument(document); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * 遍历集合 * * @param books */ private static void traverseBooks(List<Book> books) { for (Iterator<Book> iterator = books.iterator(); iterator.hasNext();) { Book book = iterator.next(); System.out.println(book); } } /** * 该方法实现了对xml文档的读取功能 * * @param document * @return */ private static List<Book> readAllElementsFromXMLDocument(Document document) { List<Book> books = new ArrayList<Book>(); Element root = document.getRootElement(); List list = root.elements(); for (int i = 0; i < list.size(); i++) { Element book = (Element) list.get(i); Book b = new Book(); String id = book.attributeValue("id"); List ll = book.elements(); b.setId(id); System.out.println(id); for (int j = 0; j < ll.size(); j++) { Element element = (Element) ll.get(j); if ("title".equals(element.getName())) { String title = element.getText(); b.setTitle(title); System.out.println(title); } if ("price".equals(element.getName())) { String price = element.getText(); double p = Double.parseDouble(price); b.setPrice(p); System.out.println(price); } } books.add(b); } return books; } /** * 通过document对象将内存中的dom树保存到新的xml文档。 * * @param document * @throws Exception */ private static void writeToNewXMLDocument(Document document) throws Exception { XMLWriter writer = new XMLWriter(new FileWriter( "src/com/zc/homeWork19/newbooks.xml")); writer.write(document); writer.close(); } /** * 该方法用于得到document对象。 * * @return * @throws Exception */ private static Document getDocument() throws Exception { SAXReader sr = new SAXReader(); Document document = sr.read("src\\books.xml"); return document; } }
Book.java
package com.zc.homeWork19; public class Book { public String title; public double price; public String id; public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String toString() { return "图书ISBN为:" + id + " 书名为:" + title + " 价格为:" + price; } }
book.xml
<?xml version="1.0" encoding="UTF-8"?> <books> <book id="book1"> <title>JAVA编程思想</title> <price>80.00</price> </book> <book id="book2"> <title>JAVA 编程理论</title> <price>100.00</price> </book> </books>
加载全部内容