import java.util.ArrayList;import java.util.Date;import java.util.Scanner;class Message {private String content;private Date timestamp;public Message(String content, Date timestamp) {this.content = content;this.timestamp = timestamp;}public String getContent() {return content;}public Date getTimestamp() {return timestamp;}}public class MessageApp {private static ArrayList messages = new ArrayList<>();public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (true) {System.out.println("请选择操作：");System.out.println("1. 短消息接收");System.out.println("2. 短列表显示所有短消息");System.out.println("3. 阅读短消息");System.out.println("4. 删除短消息");System.out.println("5. 清空所有短消息");System.out.println("0. 退出程序");int choice = scanner.nextInt();scanner.nextLine(); // 读取换行符switch (choice) {case 1:receiveMessage(scanner);break;case 2:displayMessages();break;case 3:readMessage(scanner);break;case 4:deleteMessage(scanner);break;case 5:clearMessages();break;case 0:System.exit(0);break;default:System.out.println("无效的操作，请重新选择。");}} }private static void receiveMessage(Scanner scanner) {System.out.println("请输入短消息内容：");String content = scanner.nextLine();Message message = new Message(content, new Date());if (messages.size() >= 20) {messages.remove(0);}messages.add(message);System.out.println("短消息接收成功！");}private static void displayMessages() {if (messages.size() == 0) {System.out.println("暂无短消息。");} else {System.out.println("短消息列表：");for (int i = 0; i < messages.size(); i++) {Message message = messages.get(i);System.out.println(i + 1 + ". " + message.getContent());}}}private static void readMessage(Scanner scanner) {System.out.println("请输入要阅读的短消息编号：");int index = scanner.nextInt();scanner.nextLine(); // 读取换行符if (index < 1 || index > messages.size()) {System.out.println("无效的短消息编号。");} else {Message message = messages.get(index - 1);System.out.println("短消息内容：" + message.getContent());System.out.println("短消息时间：" + message.getTimestamp());}}private static void deleteMessage(Scanner scanner) {System.out.println("请输入要删除的短消息编号：");int index = scanner.nextInt();scanner.nextLine(); // 读取换行符if (index < 1 || index > messages.size()) {System.out.println("无效的短消息编号。");} else {messages.remove(index - 1);System.out.println("短消息删除成功！");}}private static void clearMessages() {messages.clear();System.out.println("所有短消息已清空！");}}
