同学通讯录：具有数据插入、修改、删除、显示、查询和统计功能的电话簿管理程序。用Java实现。

好的，这是一个比较典型的Java项目，下面是一些实现思路和代码示例供您参考：

1. 定义一个联系人类，包括姓名、电话号码、电子邮件等属性，以及相应的 getter 和 setter 方法。

public class Contact {
    private String name;
    private String phoneNumber;
    private String email;

    public Contact(String name, String phoneNumber, String email) {
        this.name = name;
        this.phoneNumber = phoneNumber;
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

2. 定义一个通讯录类，包括联系人列表、添加联系人、删除联系人、修改联系人、查询联系人等方法。

import java.util.ArrayList;

public class AddressBook {
    private ArrayList<Contact> contacts;

    public AddressBook() {
        contacts = new ArrayList<>();
    }

    public void addContact(Contact contact) {
        contacts.add(contact);
    }

    public void removeContact(Contact contact) {
        contacts.remove(contact);
    }

    public void updateContact(Contact oldContact, Contact newContact) {
        int index = contacts.indexOf(oldContact);
        if (index >= 0) {
            contacts.set(index, newContact);
        }
    }

    public Contact findContactByName(String name) {
        for (Contact contact : contacts) {
            if (contact.getName().equals(name)) {
                return contact;
            }
        }
        return null;
    }

    public ArrayList<Contact> getAllContacts() {
        return contacts;
    }

    public int countContacts() {
        return contacts.size();
    }
}

3. 编写一个基本的用户界面，允许用户输入指令并执行相应的操作。

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        AddressBook addressBook = new AddressBook();
        Scanner scanner = new Scanner(System.in);
        boolean quit = false;
        while (!quit) {
            System.out.println("Enter command: ");
            String command = scanner.nextLine();
            switch (command) {
                case "add":
                    System.out.println("Enter name: ");
                    String name = scanner.nextLine();
                    System.out.println("Enter phone number: ");
                    String phoneNumber = scanner.nextLine();
                    System.out.println("Enter email: ");
                    String email = scanner.nextLine();
                    Contact contact = new Contact(name, phoneNumber, email);
                    addressBook.addContact(contact);
                    break;
                case "remove":
                    System.out.println("Enter name: ");
                    String nameToRemove = scanner.nextLine();
                    Contact contactToRemove = addressBook.findContactByName(nameToRemove);
                    if (contactToRemove != null) {
                        addressBook.removeContact(contactToRemove);
                    } else {
                        System.out.println("Contact not found.");
                    }
                    break;
                case "update":
                    System.out.println("Enter name to update: ");
                    String oldName = scanner.nextLine();
                    Contact oldContact = addressBook.findContactByName(oldName);
                    if (oldContact != null) {
                        System.out.println("Enter new name: ");
                        String newName = scanner.nextLine();
                        System.out.println("Enter new phone number: ");
                        String newPhoneNumber = scanner.nextLine();
                        System.out.println("Enter new email: ");
                        String newEmail = scanner.nextLine();
                        Contact newContact = new Contact(newName, newPhoneNumber, newEmail);
                        addressBook.updateContact(oldContact, newContact);
                    } else {
                        System.out.println("Contact not found.");
                    }
                    break;
                case "list":
                    for (Contact c : addressBook.getAllContacts()) {
                        System.out.println(c.getName() + " " + c.getPhoneNumber() + " " + c.getEmail());
                    }
                    break;
                case "count":
                    System.out.println("Number of contacts: " + addressBook.countContacts());
                    break;
                case "quit":
                    quit = true;
                    break;
                default:
                    System.out.println("Invalid command.");
                    break;
            }
        }
    }
}

这个程序还有很多可以改进的地方，比如可以将数据存储到文件中，添加更多的查询条件等等。但是以上代码应该可以满足您的基本需求。