import\u0020java.util.ArrayList;import\u0020java.util.Date;import\u0020java.util.Scanner;class\u0020Message\u0020{\u0020\u0020private\u0020String\u0020sender;private\u0020String\u0020content;private\u0020Date\u0020date;public\u0020Message(String\u0020sender,\u0020String\u0020content)\u0020{\u0020\u0020\u0020this.sender\u0020=\u0020sender;this.content\u0020=\u0020content;this.date\u0020=\u0020new\u0020Date();\u0020\u0020}public\u0020String\u0020getSender()\u0020{\u0020\u0020\u0020return\u0020sender;}\u0020public\u0020String\u0020getContent()\u0020{\u0020\u0020\u0020return\u0020content;}\u0020public\u0020Date\u0020getDate()\u0020{\u0020\u0020\u0020return\u0020date;}\u0020}public\u0020class\u0020MessageApp\u0020{\u0020\u0020private\u0020static\u0020ArrayList\u0020messages\u0020=\u0020new\u0020ArrayList<>();public\u0020static\u0020void\u0020main(String[]\u0020args)\u0020{\u0020\u0020\u0020Scanner\u0020scanner\u0020=\u0020new\u0020Scanner(System.in);while\u0020(true)\u0020{\u0020\u0020\u0020\u0020System.out.println("请选择操作：");System.out.println("1.\u0020短消息接收");System.out.println("2.\u0020显示短列表");System.out.println("3.\u0020阅读短消息");System.out.println("4.\u0020删除短消息");System.out.println("5.\u0020清空短消息");System.out.println("0.\u0020退出");int\u0020choice\u0020=\u0020scanner.nextInt();scanner.nextLine();\u0020//\u0020清空输入缓冲switch\u0020(choice)\u0020{\u0020\u0020\u0020\u0020case\u00201:\u0020\u0020\u0020\u0020\u0020receiveMessage(scanner);break;case\u00202:\u0020\u0020\u0020\u0020\u0020displayMessages();break;case\u00203:\u0020\u0020\u0020\u0020\u0020readMessage(scanner);break;case\u00204:\u0020\u0020\u0020\u0020\u0020deleteMessage(scanner);break;case\u00205:\u0020\u0020\u0020\u0020\u0020clearMessages();break;case\u00200:\u0020\u0020\u0020\u0020\u0020System.out.println("程序已退出。");System.exit(0);break;default:\u0020\u0020\u0020\u0020\u0020System.out.println("无效的选择，请重新输入。");\u0020\u0020\u0020\u0020}\u0020\u0020\u0020}\u0020}private\u0020static\u0020void\u0020receiveMessage(Scanner\u0020scanner)\u0020{\u0020\u0020\u0020System.out.println("请输入短消息的发送者：");String\u0020sender\u0020=\u0020scanner.nextLine();System.out.println("请输入短消息的内容：");String\u0020content\u0020=\u0020scanner.nextLine();Message\u0020message\u0020=\u0020new\u0020Message(sender,\u0020content);if\u0020(messages.size()\u0020>=\u002020)\u0020{\u0020\u0020\u0020\u0020messages.remove(0);\u0020\u0020\u0020}messages.add(message);System.out.println("短消息接收成功。");}private\u0020static\u0020void\u0020displayMessages()\u0020{\u0020\u0020\u0020for\u0020(int\u0020i\u0020=\u00200;i\u0020<\u0020messages.size();i++)\u0020{\u0020\u0020\u0020\u0020Message\u0020message\u0020=\u0020messages.get(i);System.out.println("短消息"\u0020+\u0020(i\u0020+\u00201)\u0020+\u0020":");System.out.println("发送者:\u0020"\u0020+\u0020message.getSender());System.out.println("内容:\u0020"\u0020+\u0020message.getContent());System.out.println("时间:\u0020"\u0020+\u0020message.getDate());System.out.println();\u0020\u0020\u0020\u0020}\u0020}private\u0020static\u0020void\u0020readMessage(Scanner\u0020scanner)\u0020{\u0020\u0020\u0020System.out.println("请输入要阅读的短消息的编号：");int\u0020index\u0020=\u0020scanner.nextInt();scanner.nextLine();\u0020//\u0020清空输入缓冲if\u0020(index\u0020>=\u00201\u0020&&\u0020index\u0020<=\u0020messages.size())\u0020{\u0020\u0020\u0020\u0020Message\u0020message\u0020=\u0020messages.get(index\u0020-\u00201);System.out.println("发送者:\u0020"\u0020+\u0020message.getSender());System.out.println("内容:\u0020"\u0020+\u0020message.getContent());System.out.println("时间:\u0020"\u0020+\u0020message.getDate());\u0020\u0020\u0020}else\u0020{\u0020\u0020\u0020\u0020System.out.println("无效的短消息编号。");\u0020\u0020\u0020}\u0020}private\u0020static\u0020void\u0020deleteMessage(Scanner\u0020scanner)\u0020{\u0020\u0020\u0020System.out.println("请输入要删除的短消息的编号：");int\u0020index\u0020=\u0020scanner.nextInt();scanner.nextLine();\u0020//\u0020清空输入缓冲if\u0020(index\u0020>=\u00201\u0020&&\u0020index\u0020<=\u0020messages.size())\u0020{\u0020\u0020\u0020\u0020messages.remove(index\u0020-\u00201);System.out.println("短消息删除成功。");\u0020\u0020\u0020}else\u0020{\u0020\u0020\u0020\u0020System.out.println("无效的短消息编号。");\u0020\u0020\u0020}\u0020}private\u0020static\u0020void\u0020clearMessages()\u0020{\u0020\u0020\u0020messages.clear();System.out.println("所有短消息已清空。");\u0020} }
