FileInputStream和FileOutputStream類為建立一個與檔案相關的輸入與輸出流，提供從檔案中讀取或者寫入一個位元組或一組資料的方法。而ObjectOutputStream是用來輸入物件。最後程式還有一點小問題，加入書籍會覆蓋以前加入的書籍資料，之後有時間再修改。

package test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Scanner;

public class Jmain {

	/**
	 * @param args
	 */
	static int a;

	static FileOutputStream nos=null;
	static FileInputStream nis=null;
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			nos=new FileOutputStream("savenum.txt",true);
			nis=new FileInputStream("savenum.txt");
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		m();
	}
	public static void m(){
		
		Scanner snr = new Scanner(System.in); 
		System.out.println("選擇功能");
		System.out.println("1 加入書籍");
		System.out.println("2 查詢書籍");
		System.out.println("3 退出");
		a=snr.nextInt();
		d(a);
	}
	public static void d(int a){
		int i=0,n,isbn,num=0;
		Scanner sn = new Scanner(System.in); 
		switch(a){
		case 1:{
			System.out.println("輸入需要加入的數量");
			i=sn.nextInt();
			try {
				nos.write(i);
			} catch (IOException e) {
				e.printStackTrace();
			}
			inputbook.newb();
			for(n=0;n<i;n++){
				inputbook.input();
			}
			m();
		}
		case 2:{
			try {
				num=nis.read();
				while(num==-1){
				num+=nis.read();}
			} catch (IOException e) {
				e.printStackTrace();
			}
			//System.out.println(num);
			System.out.println("輸入isbn");
			isbn=sn.nextInt();
			findBook.fba();
//			System.out.println(num);
			for(n=0;n<num;n++){
			findBook.fb(isbn);
			}
			m();
		}
		case 3:{
			break;
		}
		}
		
	}
}
 

package test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.ObjectInputStream;

public class findBook {
	static ObjectInputStream ois;
	public static void fba(){
		try {
			ois=new ObjectInputStream(new FileInputStream("save.txt"));
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public static void fb(int isbn){
		
		inputbook book=new inputbook() ;
	try {
		book=(inputbook) ois.readObject();
	} catch (IOException e1) {
		// TODO Auto-generated catch block
		e1.printStackTrace();
	} catch (ClassNotFoundException e1) {
		// TODO Auto-generated catch block
		e1.printStackTrace();
	}
		if(isbn==book.isbn)
		{
			System.out.println("ISBN:");
			System.out.println(book.isbn);
			System.out.println("價格:");
			System.out.println(book.price);
			System.out.println("書名:");
			System.out.println(book.name);
		}
		else
			System.out.println("未找到記錄");
	
	}
}
 

package test;
import java.io.*;
import java.util.Scanner;
public class inputbook implements Serializable{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	int isbn;
	int price;
	String name;
	public int getIsbn() {
		return isbn;
	}
	public void setIsbn(int isbn) {
		this.isbn = isbn;
	}
	public int getPrice() {
		return price;
	}
	public void setPrice(int price) {
		this.price = price;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	static ObjectOutputStream fos;
	static int a=1;
	public static  void newb(){
		
			try {
				fos=new ObjectOutputStream(new FileOutputStream("save.txt"));
				a=2;
			} catch (FileNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
	}
	public static void input(){
		int i,p;
		String n;
//		System.out.println(a);
		Scanner scanner = new Scanner(System.in); 
		inputbook book=new inputbook() ;
		System.out.println("請輸入ISBN：");
		i=scanner.nextInt();
//		System.out.println(i);
		book.setIsbn(i);
		System.out.println("請輸入書名：");
		n=scanner.nextLine();
		n=scanner.nextLine();
		book.setName(n);
		System.out.println("請輸入價格：");
		p=scanner.nextInt();
		book.setPrice(p);
		try {
			fos.writeObject(book);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}	
	}
}