一个简陋的java图书管理系统

import java.util.Scanner;public class Menu {  int Min = 1;  int Max = 3;  public void getMenu(){    System.out.println("1、显示/2、输入/3、查找");  }  public void getFindMenu(){    System.out.println("1、编号/2、书名/3、作者");  }  public int setMenu(){    System.out.println("输入序号:");    Scanner reader = new Scanner(System.in);    int num = reader.nextInt();    if(num >= Min || num <= Max)      return num;    else      return -1;  }}

import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.util.Scanner;import java.io.IOException;public class Book {  public void find(){    Menu menu = new Menu();    menu.getFindMenu();    Scanner reader = new Scanner(System.in);    int num = menu.setMenu();    switch(num){    case 1:      System.out.println("请输入编号");      Find(reader.next(), 0);      break;    case 2:      System.out.println("请输入书名");      Find(reader.next(), 1);      break;    case 3:      System.out.println("请输入作者");      Find(reader.next(), 2);      break;    }  }  public void Find(String s,int n){    try {      Scanner in = new Scanner(new File("res/Book.txt"));      while (in.hasNextLine()) {        String str = in.nextLine();        String[] book = str.trim().split("#");        if(book[n].compareTo(s) == 0)          System.out.println(book[0] +" "+ book[1] +" "+ book[2]);      }    } catch (FileNotFoundException e) {      e.printStackTrace();    }  }  public String findNum(String s,int n){    try {      Scanner in = new Scanner(new File("res/Book.txt"));      while (in.hasNextLine()) {        String str = in.nextLine();        String[] book = str.trim().split("#");        if(book[n].compareTo(s) == 0)          return book[n];      }    } catch (FileNotFoundException e) {      e.printStackTrace();    }    return "没有找到";  }  public String message(){    Scanner reader = new Scanner(System.in);    String str = "";    String s = "";    System.out.println("请输入编号");    str = reader.next();    if(findNum(str,0).compareTo("没有找到") != 0){      System.out.println("此编号存在输入错误");      return "@@!!";    }    s += str + "#";    System.out.println("请输入书名");    str = reader.next();    s += str + "#";    System.out.println("请输入作者");    str = reader.next();    s += str + "#/n";    return s;  }  public void setBook() {    FileOutputStream fop = null;    File file;    String content = message();    if(content.compareTo("@@!!") == 0)      return ;      try {      file = new File("res/Book.txt");      fop = new FileOutputStream(file,true);      byte[] contentInBytes = content.getBytes();      fop.write(contentInBytes);      fop.flush();      fop.close();      System.out.println("Done");    } catch (IOException e) {      e.printStackTrace();    } finally {      try {        if (fop != null) {          fop.close();        }      } catch (IOException e) {        e.printStackTrace();      }    }  }  public void getBook() {    try {      Scanner in = new Scanner(new File("res/Book.txt"));      while (in.hasNextLine()) {        String str = in.nextLine();        splitt(str);      }    } catch (FileNotFoundException e) {      e.printStackTrace();    }  }  public static String[] splitt(String str) {    String[] book = str.trim().split("#");    for (int i = 0; i < book.length; i++) {      System.out.println(book[i]);    }    System.out.println("/n*********************");    return book;  }}

public class ManageBook {   public static void main(String[] agse){    Menu menu = new Menu();    Book book = new Book();    while(true){      menu.getMenu();      int num = menu.setMenu();      switch(num){        case 1:          book.getBook();          break;        case 2:          book.setBook();          break;        case 3:          book.find();          break;        case -1:          System.out.println("输入有误");          break;        }    }  }}