java手机通讯录代码

下面是一个用Java编写的手机通讯录代码示例：

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class PhoneBook {
    private static Map<String, String> phoneBook = new HashMap<>();

    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. 添加联系人");
            System.out.println("2. 查找联系人");
            System.out.println("3. 删除联系人");
            System.out.println("4. 显示通讯录");
            System.out.println("5. 退出");
            int choice = scanner.nextInt();

            switch (choice) {
                case 1:
                    addContact(scanner);
                    break;
                case 2:
                    findContact(scanner);
                    break;
                case 3:
                    removeContact(scanner);
                    break;
                case 4:
                    displayContacts();
                    break;
                case 5:
                    System.out.println("已退出！");
                    return;
                default:
                    System.out.println("无效的选择！");
            }
        }
    }

    private static void addContact(Scanner scanner) {
        System.out.println("请输入姓名：");
        String name = scanner.next();
        System.out.println("请输入电话号码：");
        String phoneNumber = scanner.next();
        phoneBook.put(name, phoneNumber);
        System.out.println("联系人已添加！");
    }

    private static void findContact(Scanner scanner) {
        System.out.println("请输入要查找的姓名：");
        String name = scanner.next();
        String phoneNumber = phoneBook.get(name);
        if (phoneNumber == null) {
            System.out.println("未找到该联系人！");
        } else {
            System.out.println(name + " 的电话号码是：" + phoneNumber);
        }
    }

    private static void removeContact(Scanner scanner) {
        System.out.println("请输入要删除的联系人的姓名：");
        String name = scanner.next();
        String phoneNumber = phoneBook.get(name);
        if (phoneNumber == null) {
            System.out.println("未找到该联系人！");
        } else {
            phoneBook.remove(name);
            System.out.println("联系人已删除！");
        }
    }

    private static void displayContacts() {
        System.out.println("通讯录内容：");
        if (phoneBook.isEmpty()) {
            System.out.println("通讯录为空！");
        } else {
            for (String name : phoneBook.keySet()) {
                String phoneNumber = phoneBook.get(name);
                System.out.println(name + ": " + phoneNumber);
            }
        }
    }
}

这个代码使用了一个`HashMap`来存储联系人的姓名和电话号码，提供了添加联系人、查找联系人、删除联系人和显示通讯录的功能。用户可以根据提示分别选择需要的操作，在添加或查找联系人时输入姓名和电话号码，删除联系人时输入姓名即可。通讯录中的内容会实时显示给用户。