用java制作一个简单的日记本，要求有菜单，创建日记、打开日记、编辑日记、保存、退出等，并实现其功能的代码

好的，下面是一个简单的Java日记本代码实现：

import java.util.Scanner;
import java.io.*;

public class Diary {
    private static Scanner input = new Scanner(System.in);

    public static void main(String[] args) {
        boolean exit = false;

        while (!exit) {
            System.out.println("请选择操作：");
            System.out.println("1. 创建日记");
            System.out.println("2. 打开日记");
            System.out.println("3. 编辑日记");
            System.out.println("4. 保存日记");
            System.out.println("5. 退出");
            System.out.print("请选择：");

            int choice = input.nextInt();

            switch (choice) {
                case 1:
                    createDiary();
                    break;
                case 2:
                    openDiary();
                    break;
                case 3:
                    editDiary();
                    break;
                case 4:
                    saveDiary();
                    break;
                case 5:
                    exit = true;
                    break;
                default:
                    System.out.println("无效选项，请重新选择！");
                    break;
            }
        }
    }

    private static void createDiary() {
        System.out.print("请输入日记文件名：");
        String fileName = input.next();

        try {
            File file = new File(fileName);
            if (file.createNewFile()) {
                System.out.println("创建日记成功！");
            } else {
                System.out.println("日记已存在！");
            }
        } catch (IOException e) {
            System.out.println("创建日记失败：" + e.getMessage());
        }
    }

    private static void openDiary() {
        System.out.print("请输入日记文件名：");
        String fileName = input.next();

        try {
            FileReader reader = new FileReader(fileName);
            BufferedReader bufferedReader = new BufferedReader(reader);

            String line;
            while ((line = bufferedReader.readLine()) != null) {
                System.out.println(line);
            }

            bufferedReader.close();
            reader.close();
        } catch (FileNotFoundException e) {
            System.out.println("打开日记失败：文件不存在！");
        } catch (IOException e) {
            System.out.println("打开日记失败：" + e.getMessage());
        }
    }

    private static void editDiary() {
        System.out.print("请输入日记文件名：");
        String fileName = input.next();

        try {
            FileWriter writer = new FileWriter(fileName, true);
            BufferedWriter bufferedWriter = new BufferedWriter(writer);

            System.out.println("请输入日记内容（输入end结束输入）：");
            String line;
            while (!(line = input.nextLine()).equals("end")) {
                bufferedWriter.write(line);
                bufferedWriter.newLine();
            }

            bufferedWriter.close();
            writer.close();
        } catch (IOException e) {
            System.out.println("编辑日记失败：" + e.getMessage());
        }
    }

    private static void saveDiary() {
        System.out.print("请输入日记文件名：");
        String fileName = input.next();

        try {
            FileWriter writer = new FileWriter(fileName, true);
            BufferedWriter bufferedWriter = new BufferedWriter(writer);

            System.out.println("请输入要保存的内容（输入end结束输入）：");
            String line;
            while (!(line = input.nextLine()).equals("end")) {
                bufferedWriter.write(line);
                bufferedWriter.newLine();
            }

            bufferedWriter.close();
            writer.close();
        } catch (IOException e) {
            System.out.println("保存日记失败：" + e.getMessage());
        }
    }
}

这个程序实现了菜单，包括创建日记、打开日记、编辑日记、保存、退出等功能。你可以根据自己的需要修改和完善它。