教科书级代码分层思想

下面代码主要是写了一个小型的图书馆管理系统。基本功能就是增删改查。

系统虽然小，但是分层，综合应用上有很强的实际意义，作为菜鸟的我，应当好好研究下，从中吸取经验。

import java.util.List;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.Iterator;

/*
    1. 编号
    2. 书名
    3. 借出状态
*/
class Book {
    
    private int id ;
    private String name ;
    private String flag ;
    
    public void setId(int id){
        this.id = id ;
    }
    public int getId(){
        return this.id;
    }
    
    public void setName(String name){
        this.name = name ;
    }
    public String getName(){
        return this.name;
    }
    
    public void setFlag(String flag){
        this.flag = flag ;
    }
    public String getFlag(){
        return this.flag;
    }
}

class Manager{
    private List<Book> list ;
    
    final static int maxCount = 100;
    
    public List<Book> getList(){
        return initList();
    }
    
    private List<Book> initList() {
        
        this.list = new ArrayList<Book>();
        Book book1 = new Book();
        book1.setId(1);
        book1.setName("水浒传");
        book1.setFlag("可借");
        
        list.add(book1);
        
        Book book2 = new Book();
        book2.setId(2);
        book2.setName("三国演义");
        book2.setFlag("可借");
        
        list.add(book2);
        
        Book book3 = new Book();
        book3.setId(3);
        book3.setName("西游记");
        book3.setFlag("已借出");
        
        list.add(book3);
        
        return this.list;
    }
    
    /*
        添加
    */
    public void addBookToList(Book book) {
        if(this.list.size() <= maxCount) {
            this.list.add(book);
        }
    }
    
    /*
        删除
    */
    public boolean delBookFromList(Book book) {
        boolean flag = false ;
        Iterator<Book> it = this.list.iterator();
        while(it.hasNext()) {
            Book has_book = it.next();
            if(has_book.getName.equals(book.getName())){
                it.remove();
                flag = true;
            }
        }
        return flag;
    }
    
    public boolean borrowBook(Book book){
        boolean flag = false;
        Iterator<Book> it = this.list.iterator();
        while(it.hasNext()) {
            Book has_book = it.next();
            if(has_book.getName.equals(book.getName()){
                if("可借".equals(has_book.getFlag())){
                    flag = true ;
                }
            }
        }
        return flag ;
    }
    
}

public class BookManager {
    
    public static void main(String args[]){
        List<Book> bookList = new ArrayList<Book>();
        Manager m = new Manager();
        
        bookList = m.getList();
        
        Iterator<Book> it = bookList.iterator();
        while(it.hasNext()){
            Book book = it.next();
            System.out.println(
                "  编号:" + book.getId() +
                "  书名:" + book.getName() + 
                "  状态:" + book.getFlag()
            );
        }
        
        Book boo1 = new Book();
        boo1.setId(4);
        boo1.setName("大话西游");
        boo1.setFlag("可借");
        
        m.addBookToList(boo1);
        
        Scanner scanner = new Scanner(System.in);
        String name = scanner.next();
        
        Book removeBook = new Book();
        removeBook.setName(name);
        
        boolean flag = m.delBookFromList(removeBook);
        
        Book b_Book = new Book();
        b_Book.setName(scanner.next());
        boolean  borrowFlag = m.borrowBook(b_Book);
    }
    
}