import java.util.ArrayList;import java.util.List;import java.util.Scanner;public class ShortMessageApp {public static void main(String[] args) {List messages = new ArrayList<>();Scanner scanner = new Scanner(System.in);int choice;do {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. 清空短消息");System.out.println("0. 退出");System.out.print("请选择操作：");choice = scanner.nextInt();switch (choice) {case 1:receiveMessage(messages, scanner);break;case 2:displayMessages(messages);break;case 3:readMessage(messages, scanner);break;case 4:deleteMessage(messages, scanner);break;case 5:clearMessages(messages);break;case 0:System.out.println("程序已退出。");break;default:System.out.println("无效的选择，请重新输入。");break;}System.out.println(); } while (choice != 0);scanner.close();}public static void receiveMessage(List messages, Scanner scanner) {System.out.print("请输入短消息内容：");String message = scanner.next();if (messages.size() >= 20) {messages.remove(0);}messages.add(message);System.out.println("短消息已接收。");}public static void displayMessages(List messages) {if (messages.isEmpty()) {System.out.println("短消息列表为空。");} else {System.out.println("短消息列表：");for (int i = 0; i < messages.size(); i++) {System.out.println((i + 1) + ". " + messages.get(i));}}}public static void readMessage(List messages, Scanner scanner) {if (messages.isEmpty()) {System.out.println("短消息列表为空。");} else {System.out.print("请输入要阅读的短消息编号：");int index = scanner.nextInt();if (index < 1 || index > messages.size()) {System.out.println("无效的短消息编号。");} else {String message = messages.get(index - 1);System.out.println("短消息内容：" + message);}}}public static void deleteMessage(List messages, Scanner scanner) {if (messages.isEmpty()) {System.out.println("短消息列表为空。");} else {System.out.print("请输入要删除的短消息编号：");int index = scanner.nextInt();if (index < 1 || index > messages.size()) {System.out.println("无效的短消息编号。");} else {String message = messages.remove(index - 1);System.out.println("短消息已删除：" + message);}}}public static void clearMessages(List messages) {messages.clear();System.out.println("短消息已清空。");}}
