xml和集合混合使用-图书管理器

 package com.book;

 public class Book {
     private int id;  //图书编号
     private String name;      //图书名称
     private String author;  //图书作者
     private int states;  //书本借出状态  0可借阅 1已借出
     private float price;  //图书价格
     private String date;  //借出时间
     private int count;  //借出次数

     public Book() {
     }

     public Book(int id,String name, String author, int states, float price, String date, int count) {
         this.id=id;
         this.name = name;
         this.author = author;
         this.states = states;
         this.price = price;
         this.date = date;
         this.count = count;
     }

     public int getId() {
         return id;
     }

     public void setId(int id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getAuthor() {
         return author;
     }
     public void setAuthor(String author) {
         this.author = author;
     }
     public int getStates() {
         return states;
     }
     public void setStates(int states) {
         this.states = states;
     }
     public float getPrice() {
         return price;
     }
     public void setPrice(float price) {
         this.price = price;
     }
     public String getDate() {
         return date;
     }
     public void setDate(String date) {
         this.date = date;
     }
     public int getCount() {
         return count;
     }
     public void setCount(int count) {
         this.count = count;
     }

     @Override
     public String toString() {
         return this.id + "\t\t"  +(this.states==0? "可借阅":"已借出")+ "\t" + this.name + "\t"
                 + this.date+ "\t" + this.count;
     }

 }

 package com.book;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
 import java.util.List;

 import org.dom4j.Document;
 import org.dom4j.DocumentException;
 import org.dom4j.Element;
 import org.dom4j.io.OutputFormat;
 import org.dom4j.io.SAXReader;
 import org.dom4j.io.XMLWriter;

 import com.book.Book;

 public class XmlUtil {

     /**
      * 解析xml, 并把xml中的图书转换成集合输出
      * @return  图书集合
      */
     public static List<Book> queryBooks(){
         List<Book> booksList=new ArrayList<Book>();
         SAXReader saxReader=new SAXReader();
         try {
             Document doc=saxReader.read(new File("books\\books.xml"));
             //获取根节点
             Element root=doc.getRootElement();
             //返回集合
             List<Element> eleBooks=root.elements("book");
             //遍历集合，从集合里找到每一本书
             for (Element eleBook : eleBooks) {
                 Book b=new Book();
                 b.setId(Integer.parseInt(eleBook.attributeValue("id")));  //赋值图书编号，是根据xml的book元素的id获得值
                 b.setName(eleBook.element("name").getText());  //赋值书名，根据book元素下的name元素获得文本内容
                 b.setAuthor(eleBook.element("author").getText()); //赋值作者，根据book元素下的author元素获得文本内容
                 b.setPrice(Float.parseFloat(eleBook.element("price").getText()));  //赋值租金，根据book元素下的price元素获得文本内容
                 b.setStates(Integer.parseInt(eleBook.element("states").getText()));  //赋值状态，根据book元素下的states元素获得文本内容
                 b.setCount(Integer.parseInt(eleBook.element("count").getText()));  //赋值借出次数，根据book元素下的count元素获得文本内容
                 b.setDate(eleBook.element("date").getText());  //赋值借出时间，根据book元素下的date元素获得文本内容

                 booksList.add(b);  //把赋值好的图书添加到ArrayList集合
             }

         } catch (DocumentException e) {
             e.printStackTrace();
         }
         return booksList;
     }

     /**
      * 把集合里的图书写入xml里
      * @param books
      * @return
      */
     public static boolean saveBook(List<Book> books) {
         SAXReader reader=new SAXReader();
         Document doc =reader.getDocumentFactory().createDocument();  //创建一个新的xml文档
         Element root=doc.addElement("books");  //新增根元素<books>

         for (Book book : books) {
             Element eleBook=root.addElement("book");
             eleBook.addAttribute("id", book.getId()+"");  //新增属性id，添加节点文本内容
             eleBook.addElement("name").setText(book.getName());  //新增name节点，添加节点文本内容
             eleBook.addElement("author").setText(book.getAuthor());  //新增author节点，添加节点文本内容
             eleBook.addElement("price").setText(book.getPrice()+"");  //新增price节点，添加节点文本内容，float类型转String类型
             eleBook.addElement("states").setText(book.getStates()+"");  //新增states节点，添加节点文本内容
             eleBook.addElement("count").setText(book.getCount()+"");  //新增count节点，添加节点文本内容
             eleBook.addElement("date").setText(book.getDate()==null?"":book.getDate());  //新增date节点，添加节点文本内容,三目运算符判断归还日期是否为空
         }

         try {
             //创建XML输出流对象,并设置xml对齐样式
             XMLWriter writer=new XMLWriter(new FileOutputStream("books\\books.xml"),OutputFormat.createPrettyPrint());
             //把内容写入xml文档
             writer.write(doc);
             //关闭输出流
             writer.close();
         } catch (UnsupportedEncodingException | FileNotFoundException e) {
             e.printStackTrace();
             return false;
         } catch (IOException e) {
             e.printStackTrace();
             return false;
         }
         return true;
     }

     /**
      * 测试集合内容是否写入xml中
      * @param args
      */
     public static void main(String[] args) {
 /*        //创建ArrayList<Book>集合对象
         List<Book> books=new ArrayList<Book>();
         //往集合里添加新的图书
         books.add(new Book(001,"失落邮寄","陈先生",0,15,"",8));
         books.add(new Book(002,"人性的弱点","扎先生",1,20,"2018-12-22",18));
         //调用方法，把集合里的图书写入xml里
         boolean b=saveBook(books);
         System.out.println(b);*/

         //创建ArrayList<Book>集合对象，调用集合查询方法
         List<Book> booksList=queryBooks();
         //遍历每一本书，重写tostring方法输出book
         for (Book book : booksList) {
             System.out.println(book);
         }
     }
 }

 package com.book;

 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.List;

 import com.book.Book;
 import com.util.XmlUtil;

 public class BookManagement {

     /**
      * 图书新增
      * @param b
      */
     public void addBook(Book b) {
         //创建ArrayList<Book>集合对象，调用集合查询方法
         List<Book>  booksList=XmlUtil.queryBooks();
         for (Book book : booksList) {
             if(book.getName().equals(b.getName())) {
                 System.out.println("图书已存在，新增失败！");
                 return;
             }
         }
         //判断图书编号，如果没有图书编号设置1，否则在最后一本图书的编号上加1
         if(booksList.size()==0) {
             b.setId(1);
         }else {
             b.setId(booksList.get(booksList.size()-1).getId()+1);
         }
         booksList.add(b);  //在新增的图书添加到集合里

         XmlUtil.saveBook(booksList);  //调用保存方法把集合写入xml里
         System.out.println("新增图书成功！");
     }

     /**
      * 图书查看，重写toString()方法
      */
     public void queryBooks() {
         List<Book> booksList=XmlUtil.queryBooks();
         System.out.println("序号\t\t状态\t\t名称\t\t借出日期\t\t借出次数");
         for (Book book : booksList) {
             System.out.println(book);
         }
     }

     /**
      * 图书删除
      * @param name
      */
     public void deleteBook(String name) {
         List<Book> booksList=XmlUtil.queryBooks();
         //遍历集合里的图书
         for(int i=0;i<booksList.size();i++) {
             //判断输入的图书名字是否存在集合里，且是否是可借阅状态
             if(booksList.get(i).getName().equals(name) && booksList.get(i).getStates() == 0) {
                 booksList.remove(i);  //删除图书
                 System.out.println("删除成功！");
                 XmlUtil.saveBook(booksList);  //保存
                 return;
             }else if(booksList.get(i).getName().equals(name) && booksList.get(i).getStates() == 1){
                 System.out.println("图书未归还不能删除！");
                 return;
             }
         }
         System.out.println("你要删除的图书不存在！");
     }

     /**
      * 图书借出
      * @param name
      */
     public void loanBook(String name) {
         queryBooks();  //查询所有图书
         List<Book> booksList=XmlUtil.queryBooks();
         //当前的日期
         Date date=new Date();
         //将日期和时间的格式变为我们要求的格式：年-月-日
         SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
         String sdate=sdf.format(date);
         //检测图书是否存在
         for (Book book : booksList) {
                 if(book.getName().equals(name) && book.getStates()==0) {
                     book.setStates(1);
                     book.setCount(book.getCount()+1);
                     book.setDate(sdate);
                     System.out.println("图书借阅成功！");
                     XmlUtil.saveBook(booksList);  //保存
                     return;
                 }else if(book.getName().equals(name) && book.getStates()==1) {
                     System.out.println("你要借阅的图书已借出!");
                     return;
                 }
         }
         System.out.println("你要借阅的图书不存在！");
     }

     /**
      * 图书归还
      * @param name
      */
     public void giveBook(String name) {
         List<Book> booksList=XmlUtil.queryBooks();

         for (Book book : booksList) {
             if(book.getName().equals(name) && book.getStates()==1) {
                 book.setStates(0);
                 try {
                     //当前的日期
                     Date date=new Date();
                     //将日期和时间的格式变为我们要求的格式：年-月-日
                     SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
                     String sdate=sdf.format(date);
                     Date passDate = sdf.parse(book.getDate());   //String类型转Date类型
                     long time = (date.getTime() - passDate.getTime())/1000/3600/24;  //图书租赁的时间
                     System.out.println("\""+book.getName()+"\""+"归还成功！\n借出日期是："+book.getDate()+"\n归还日期为："+sdate+"\n应付租金："+time+"元");
                     book.setDate("");  //清空图书借出时间
                     XmlUtil.saveBook(booksList);  //保存
                     return;
                 } catch (ParseException e) {
                     e.printStackTrace();
                 }
             }else if(book.getName().equals(name) && book.getStates()==0){
                 System.out.println("图书未借出，无需归还！");
                 return;
             }
         }
         System.out.println("不存在你要归还的图书！");
         }
 }

 package com.book;

 import java.util.Scanner;

 import com.book.Book;
 import com.book.service.BookManagement;

 public class BookMain {
     public static void main(String[] args) {
         Scanner input=new Scanner(System.in);
         BookManagement bm=new BookManagement();
         int zero =-1;
         do {
             System.out.println("欢迎使用迷你图书管理器\n------------------------------------------");
             System.out.println("1、新增图书\n2、查看图书\n3、删除图书\n4、借出图书\n5、归还图书\n6、退出系统\n------------------------------------------");
             System.out.print("请选择：");
             int choose=input.nextInt();
             switch(choose) {
                 case 1:
                     //新增图书
                     Book b=new Book();
                     System.out.print("请输入图书的名称：");
                     b.setName(input.next());
                     System.out.print("请输入图书的作者：");
                     b.setAuthor(input.next());
                     System.out.print("请输入图书价格：");
                     b.setPrice(input.nextFloat());
                     bm.addBook(b);
                     break;
                 case 2:
                     //查看图书
                     bm.queryBooks();
                     break;
                 case 3:
                     //删除图书
                     System.out.print("请输入要删除的图书名称：");
                     String name = input.next();
                     bm.deleteBook(name);
                     break;
                 case 4:
                     //借出图书
                     System.out.print("请输入要借阅图书的名称：");
                     name=input.next();
                     bm.loanBook(name);
                     break;
                 case 5:
                     //归还图书
                     System.out.print("请输入要归还的图书名称：");
                     name=input.next();
                     bm.giveBook(name);
                     break;
                 case 6:
                     //退出系统
                     System.out.println("欢迎再次使用！");
                     return;
             }
             System.out.print("输入0返回：");
             zero = input.nextInt();
         }while(zero==0);
         System.out.println("谢谢使用！");
     }
 }

需要注意的是创建项目后首先要导入这个jar包