java程序设计电话查询系统

首先，我们需要创建一个Contact类来存储联系人的信息。

public class Contact {
    private String name;
    private String phoneNumber;
    public Contact(String name, String phoneNumber) {
        this.name = name;
        this.phoneNumber = phoneNumber;
    }
    public String getName() {
        return name;
    }
    public String getPhoneNumber() {
        return phoneNumber;
    }
}

然后我们可以创建一个PhoneBook类来实现电话查询系统：

import java.util.HashMap;
import java.util.Scanner;
public class PhoneBook {
    private HashMap<String, Contact> phoneBook;
    public PhoneBook() {
        phoneBook = new HashMap<>();
    }
    public void addContact(String name, String phoneNumber) {
        phoneBook.put(name, new Contact(name, phoneNumber));
    }
    public Contact getContact(String name) {
        return phoneBook.get(name);
    }
    public void printContacts() {
        for (Contact contact : phoneBook.values()) {
            System.out.println("Name: " + contact.getName() + ", Phone Number: " + contact.getPhoneNumber());
        }
    }
    public static void main(String[] args) {
        PhoneBook phoneBook = new PhoneBook();
        Scanner scanner = new Scanner(System.in);
        boolean isRunning = true;
        while (isRunning) {
            System.out.println("Enter 1 to add contact, 2 to search contact, 3 to print all contacts or 4 to exit.");
            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    System.out.println("Enter contact name:");
                    String name = scanner.next();
                    System.out.println("Enter contact phone number:");
                    String phoneNumber = scanner.next();
                    phoneBook.addContact(name, phoneNumber);
                    break;
                case 2:
                    System.out.println("Enter contact name to search:");
                    String searchName = scanner.next();
                    Contact contact = phoneBook.getContact(searchName);
                    if (contact != null) {
                        System.out.println("Contact found: " + contact.getName() + ", Phone Number: " + contact.getPhoneNumber());
                    } else {
                        System.out.println("Contact not found.");
                    }
                    break;
                case 3:
                    phoneBook.printContacts();
                    break;
                case 4:
                    isRunning = false; // Exit the program.
                    break;
                default:
                    System.out.println("Invalid choice, please enter a valid option.");
            }
        }
        scanner.close();
    }
}

这个程序允许用户添加联系人信息，搜索联系人信息，打印所有联系人信息或者退出程序，用户可以通过输入相应的数字来选择操作，这是一个简单的命令行程序，你可以根据需要添加更多的功能，比如删除联系人，修改联系人信息等。