library.java

java lab4 图书馆程序 有两个class分别是book和library object book需要添加到library中

import java.io.*;
public class Library {
	private Book[] books;
	private int noOfBooks;
	public Library()
	{
		books=new Book[0];
		noOfBooks=0;
	}
	public Library(Book books[])
	{
		noOfBooks=books.length;
		for(int i=0;i<noOfBooks;i++)
		{
			this.books[i]=books[i];
		}
	}
	public void addBook(Book book)
	{
		Book temp[]=new Book[noOfBooks];
		if(noOfBooks==0)
		{
			books=new Book[1];
			books[0]=(Book)book.clone();
			noOfBooks++;
		}
		else if(noOfBooks>0)
		{
			
			for(int i=0;i<noOfBooks;i++)
			{
				temp[i]=(Book)books[i].clone();
			}
			books=new Book[noOfBooks+1];
			for(int i=0;i<noOfBooks;i++)
			{
				books[i]=(Book)temp[i].clone();
			}
			books[noOfBooks]=book;
			noOfBooks++;
		}
	}
	public Book getBook(int index)
	{
		return this.books[index];
	}
	public String toString()
	{
		String out="";
		for(int i=0;i<noOfBooks;i++)
		{
			out+="The "+(i+1)+"th book"+" id="+books[i].getID_number()+" author: "+books[i].getAuthor_of_book()+"\n";
			out+="             title:"+books[i].getTitle_of_book()+"\n";
			out+="             year ="+books[i].getYear()+" price="+books[i].getPrice()+"$"+"\n";
		}
		return out;
	}
	public void Sort_title()
	{
		int i,j;
		Book temp;
		for(i=0;i<noOfBooks;i++)
		{
			if(this.books[i]==null)
				break;
			for(j=i+1;j<noOfBooks;j++)
			{
				if(this.books[j]==null)
					break;
				if(this.books[j].Smaller_title(this.books[i]))
				{
					temp=(Book)this.books[i].clone();
					this.books[i]=(Book)this.books[j].clone();
					this.books[j]=(Book)temp.clone();
				}
			}
		}
	}
	public void Sort_author()
	{
		int i,j;
		Book temp;
		for(i=0;i<noOfBooks;i++)
		{
			if(this.books[i]==null)
				break;
			for(j=i+1;j<noOfBooks;j++)
			{
				if(this.books[j]==null)
					break;
				if(this.books[j].Smaller_author(this.books[i]))
				{
					temp=(Book)this.books[i].clone();
					this.books[i]=(Book)this.books[j].clone();
					this.books[j]=(Book)temp.clone();
				}
			}
		}
	}
	public void Sort_id_number()
	{
		int i,j;
		Book temp;
		for(i=0;i<noOfBooks;i++)
		{
			if(this.books[i]==null)
				break;
			for(j=i+1;j<noOfBooks;j++)
			{
				if(this.books[j]==null)
					break;
				if(this.books[j].Smaller_id_number(this.books[i]))
				{
					temp=(Book)this.books[i].clone();
					this.books[i]=(Book)this.books[j].clone();
					this.books[j]=(Book)temp.clone();
				}
			}
		}
	}
	public void Sort_Year()
	{
		int i,j;
		Book temp;
		for(i=0;i<noOfBooks;i++)
		{
			if(this.books[i]==null)
				break;
			for(j=i+1;j<noOfBooks;j++)
			{
				if(this.books[j]==null)
					break;
				if(this.books[j].Smaller_year(this.books[i]))
				{
					temp=(Book)this.books[i].clone();
					this.books[i]=(Book)this.books[j].clone();
					this.books[j]=(Book)temp.clone();
				}
			}
		}
	}
	public void Sort_price()
	{
		int i,j;
		Book temp;
		for(i=0;i<noOfBooks;i++)
		{
			if(this.books[i]==null)
				break;
			for(j=i+1;j<noOfBooks;j++)
			{
				if(this.books[j]==null)
					break;
				if(this.books[j].Smaller_price(this.books[i]))
				{
					temp=(Book)this.books[i].clone();
					this.books[i]=(Book)this.books[j].clone();
					this.books[j]=(Book)temp.clone();
				}
			}
		}
	}
	public void WriteToFile()throws IOException
	{
		try{
			BufferedWriter out=new BufferedWriter(new FileWriter("library.txt"));
			out.write(noOfBooks+"\n");
			for(int i=0;i<noOfBooks;i++)
			{
				books[i].WriteToFile(out);
			}	
			out.close();
		}catch(IOException e){}
	}
	public void ReadFromFile()throws IOException
	{	
		try{
			BufferedReader in=new BufferedReader(new FileReader("library.txt"));
			noOfBooks=Integer.parseInt(in.readLine());
			for(int i=0; i<noOfBooks; i++)
				books[i].ReadFromFile(in);
			in.close();
		}catch(IOException e){}
	}
}