基于Java的图书信息管理系统（用XML做数据库存储数据信息）

package com.zrrd.xml.dom; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JTextField; import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.io.SAXReader; import org.dom4j.io.XMLWriter; public class BookDao extends JFrame { // class MyException extends Exception{ // public MyException(){ // super(); // } // public MyException(String message){ // super(message); // } // } // public static void addBook(String bookid,String bookname,String author,String price,String type,String shelf,String press, String data,String remarks,String booknumber,String book_paginal_number) { //声明一个文件输出流 FileOutputStream fos = null; try { //1、根据指定的xml生成Document对象 SAXReader reader = new SAXReader(); Document document = reader.read("xml/books.xml"); //2、在Document对象的根节点下生成book节点 //得到当前文档的子节点 Element rootElement = document.getRootElement();//根据根元素 List<Element> list = rootElement.elements() ; //遍历List的方法 for (Element e:list){ //System.out.println(e.attributeValue("bookid")); if(e.attributeValue("bookid").equals(bookid)){ JOptionPane.showMessageDialog(null, "此书信息已存在"); return; } } //在跟元素下添加一个新元素(标签) Element bookElement = rootElement.addElement("book"); //3、给book节点添加属性 bookid和子节点 name,author,price //给bookElement添加属性 bookElement.addAttribute("bookid", bookid); //在bookElement中添加子元素并设置标签文字 bookElement.addElement("name").setText(bookname+""); if(bookname == null || "".equals(bookname.trim())) { JOptionPane.showMessageDialog(null, "名字不能为空"); throw new NullPointerException("名字不能为空"); } if(bookname.charAt(0)==' ') { JOptionPane.showMessageDialog(null, "名字不能以空格开头"); throw new NullPointerException("名字不能以空格开头"); } bookElement.addElement("author").setText(author+""); bookElement.addElement("price").setText(price+""); bookElement.addElement("type").setText(type+""); bookElement.addElement("press").setText(press+""); bookElement.addElement("data").setText(data+""); bookElement.addElement("remarks").setText(remarks+""); bookElement.addElement("booknumber").setText(booknumber+""); bookElement.addElement("paginal_number").setText(book_paginal_number+""); bookElement.addElement("shelf").setText(shelf+""); //4、根据添加之后的Document对象再生成一次(对原有文件进行替换) //将document放入流中 fos = new FileOutputStream("xml/books.xml");//写回源文件(打算替换) XMLWriter writer = new XMLWriter(fos);// //根据改完的document再写一次 writer.write(document); JOptionPane.showMessageDialog(null, "添加成功"); } catch(Exception e) { e.printStackTrace(); } finally { //关流 if(fos != null) { try { fos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } public static List<Map<String,Object>> inquriyBook(String bookID) { //声明List<Map<String,Object>>对象，保存读取到的信息 List<Map<String,Object>> bookList = new ArrayList<Map<String,Object>>(); //利用dom4j读取xml文件 //声明文件输出流 //List<Element> list = new ArrayList<Element>(); FileOutputStream fos = null; try { //将源文件放入流中(Document对象) 1 //创建文档解析器 SAXReader reader = new SAXReader(); //根据指定的XML生成对应dom对象(流) Document document = reader.read("xml/books.xml"); Element bookElement = (Element)document.selectSingleNode("//book[@bookid='"+bookID+"']"); //找到流中book标签 //List<Element> books =document.selectNodes("//book"); //2找节点集合 //遍历所有的book节点 //for(Element bookElement : books) // { //读取出book的name,author,price,bookid //从元素中得到bookid属性 String bookid = bookElement.attributeValue("bookid"); //读取bookElement下的(唯一)子节点 // Element nameElement = (Element)bookElement.selectSingleNode("name"); // Element authorElement = (Element)bookElement.selectSingleNode("author"); // Element priceElement = (Element)bookElement.selectSingleNode("price"); // Element typeElement = (Element)bookElement.selectSingleNode("type"); // Element shelfElement = (Element)bookElement.selectSingleNode("shelf"); // Element pressElement = (Element)bookElement.selectSingleNode("press"); // Element dataElement = (Element)bookElement.selectSingleNode("data"); // Element remarksElement = (Element)bookElement.selectSingleNode("remarks"); // Element booknumberElement = (Element)bookElement.selectSingleNode("booknumber"); // Element paginal_numberElement = (Element)bookElement.selectSingleNode("paginal_number"); //得到书名,作者,价格 String bookname = bookElement.selectSingleNode("name").getText();//得到标签间夹的文本 String author = bookElement.selectSingleNode("author").getText(); String price = bookElement.selectSingleNode("price").getText(); String type = bookElement.selectSingleNode("type").getText(); String shelf = bookElement.selectSingleNode("shelf").getText(); String press = bookElement.selectSingleNode("press").getText(); String data = bookElement.selectSingleNode("data").getText(); String remarks = bookElement.selectSingleNode("remarks").getText(); String booknumber = bookElement.selectSingleNode("booknumber").getText(); String paginal_number = bookElement.selectSingleNode("paginal_number").getText(); //将它放入Map中 Map<String,Object> book = new HashMap<String,Object>(); book.put("BOOKID", bookid); book.put("BOOKNAME", bookname); book.put("AUTHOR", author); book.put("PRICE", price); book.put("PRESS", press); book.put("TYPE", type); book.put("SHELF", shelf); book.put("DATA", data); book.put("REMARKS", remarks); book.put("BOOKNUMBER", booknumber); book.put("PAGINAL_NUMBER", paginal_number); //将装好值得Map放入List bookList.add(book); //} } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); JOptionPane.showMessageDialog(null, "信息不存在"); } finally { if(fos != null) { try { fos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } return bookList; } public static void deleteBook(String bookid) { //定义文件输出流 FileOutputStream fos = null; try { //根据当前xml文件生成document对象 SAXReader reader = new SAXReader(); Document document = reader.read("xml/books.xml"); //在document对象中得到根节点 Element rootElement = document.getRootElement(); //再找到bookid对应的节点 Element bookElement = (Element) document.selectSingleNode("//book[@bookid='"+bookid+"']"); bookElement.selectSingleNode("name"); //在根节点下删除该节点 rootElement.remove(bookElement); //将删除完毕的document再次生成xml（再写一遍） fos = new FileOutputStream("xml/books.xml"); XMLWriter writ