模拟短消息接收和有关操作最多存储20条短消息所编写的程序应包含且不限于如下功能：①短消息接收如果短消息总数超出20条则删除最早的短消息。②短列表显示所有短消息。③阅读任意一条短消息。④删除任意一条短消息。消除所有短消息。具有操作功能菜单。Java编写

以下是一个使用Java编写的简单程序，实现了上述功能：

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

public class ShortMessageManager {
    private static final int MAX_MESSAGES = 20;
    private List<Message> messages;

    public ShortMessageManager() {
        this.messages = new ArrayList<>();
    }

    public void receiveMessage(String content) {
        if (messages.size() >= MAX_MESSAGES) {
            messages.remove(0);
        }
        Message message = new Message(content);
        messages.add(message);
        System.out.println("收到一条新消息：\"" + content + "\"");
    }

    public void displayMessages() {
        if (messages.isEmpty()) {
            System.out.println("没有任何短消息。");
        } else {
            for (int i = 0; i < messages.size(); i++) {
                System.out.println((i + 1) + ". " + messages.get(i).getContent());
            }
        }
    }

    public void readMessage(int index) {
        if (index < 1 || index > messages.size()) {
            System.out.println("无效的消息索引。");
        } else {
            Message message = messages.get(index - 1);
            System.out.println("消息内容：\"" + message.getContent() + "\"");
            message.setRead(true);
        }
    }

    public void deleteMessage(int index) {
        if (index < 1 || index > messages.size()) {
            System.out.println("无效的消息索引。");
        } else {
            Message message = messages.get(index - 1);
            messages.remove(message);
            System.out.println("成功删除消息：\"" + message.getContent() + "\"");
        }
    }

    public void deleteAllMessages() {
        messages.clear();
        System.out.println("成功删除所有消息。");
    }

    public static void main(String[] args) {
        ShortMessageManager manager = new ShortMessageManager();
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 接收短消息");
            System.out.println("2. 显示短消息列表");
            System.out.println("3. 阅读短消息");
            System.out.println("4. 删除短消息");
            System.out.println("5. 删除所有短消息");
            System.out.println("0. 退出程序");

            int choice = scanner.nextInt();
            scanner.nextLine(); // 消耗换行符

            switch (choice) {
                case 0:
                    System.out.println("程序已退出。");
                    return;
                case 1:
                    System.out.println("请输入短消息内容：");
                    String content = scanner.nextLine();
                    manager.receiveMessage(content);
                    break;
                case 2:
                    manager.displayMessages();
                    break;
                case 3:
                    System.out.println("请输入要阅读的短消息的索引：");
                    int readIndex = scanner.nextInt();
                    scanner.nextLine(); // 消耗换行符
                    manager.readMessage(readIndex);
                    break;
                case 4:
                    System.out.println("请输入要删除的短消息的索引：");
                    int deleteIndex = scanner.nextInt();
                    scanner.nextLine(); // 消耗换行符
                    manager.deleteMessage(deleteIndex);
                    break;
                case 5:
                    manager.deleteAllMessages();
                    break;
                default:
                    System.out.println("无效的操作。");
            }
            System.out.println();
        }
    }
}

class Message {
    private String content;
    private Date timestamp;
    private boolean isRead;

    public Message(String content) {
        this.content = content;
        this.timestamp = new Date();
        this.isRead = false;
    }

    public String getContent() {
        return content;
    }

    public Date getTimestamp() {
        return timestamp;
    }

    public boolean isRead() {
        return isRead;
    }

    public void setRead(boolean read) {
        isRead = read;
    }
}

这个程序使用了一个ShortMessageManager类来管理短消息，并提供了接收、显示、阅读、删除和删除所有短消息的功能。用户可以通过选择菜单中的选项来执行相应的操作