通过java和mongodb数据库写出自行车管理系统的管理员页面、学员页面、自行车页面和查询页面的代码

以下是一个简单的自行车管理系统的Java代码示例，使用MongoDB作为后端数据库。

管理员页面：

import java.util.Scanner;
import org.bson.Document;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import static com.mongodb.client.model.Filters.*;

public class AdminPage {
    private MongoDatabase database;
    private MongoCollection<Document> bikeCollection;

    public AdminPage(MongoDatabase database) {
        this.database = database;
        this.bikeCollection = database.getCollection("bikes");
    }

    public void display() {
        Scanner scanner = new Scanner(System.in);
        int choice = -1;

        while (choice != 0) {
            System.out.println("1. Add bike");
            System.out.println("2. Remove bike");
            System.out.println("0. Exit");
            System.out.print("Enter your choice: ");
            choice = scanner.nextInt();

            switch(choice) {
                case 1:
                    addBike();
                    break;
                case 2:
                    removeBike();
                    break;
                case 0:
                    System.out.println("Exiting...");
                    break;
                default:
                    System.out.println("Invalid choice.");
            }
        }

        scanner.close();
    }

    private void addBike() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter bike ID: ");
        int id = scanner.nextInt();
        System.out.print("Enter bike name: ");
        String name = scanner.next();
        System.out.print("Enter bike type: ");
        String type = scanner.next();
        System.out.print("Enter bike price: ");
        double price = scanner.nextDouble();

        Document bike = new Document();
        bike.append("_id", id)
            .append("name", name)
            .append("type", type)
            .append("price", price);

        bikeCollection.insertOne(bike);

        System.out.println("Bike added successfully.");
    }

    private void removeBike() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter bike ID: ");
        int id = scanner.nextInt();

        bikeCollection.deleteOne(eq("_id", id));

        System.out.println("Bike removed successfully.");
    }
}

学员页面：

import java.util.Scanner;
import org.bson.Document;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import static com.mongodb.client.model.Filters.*;

public class StudentPage {
    private MongoDatabase database;
    private MongoCollection<Document> bikeCollection;

    public StudentPage(MongoDatabase database) {
        this.database = database;
        this.bikeCollection = database.getCollection("bikes");
    }

    public void display() {
        Scanner scanner = new Scanner(System.in);
        int choice = -1;

        while (choice != 0) {
            System.out.println("1. View all bikes");
            System.out.println("2. View bike by ID");
            System.out.println("0. Exit");
            System.out.print("Enter your choice: ");
            choice = scanner.nextInt();

            switch(choice) {
                case 1:
                    viewAllBikes();
                    break;
                case 2:
                    viewBikeById();
                    break;
                case 0:
                    System.out.println("Exiting...");
                    break;
                default:
                    System.out.println("Invalid choice.");
            }
        }

        scanner.close();
    }

    private void viewAllBikes() {
        System.out.println("Bikes:");
        for(Document doc : bikeCollection.find()) {
            System.out.println(doc.toJson());
        }
    }

    private void viewBikeById() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter bike ID: ");
        int id = scanner.nextInt();

        Document bike = bikeCollection.find(eq("_id", id)).first();

        if (bike != null) {
            System.out.println(bike.toJson());
        } else {
            System.out.println("Bike not found.");
        }
    }
}

自行车页面：

import java.util.Scanner;
import org.bson.Document;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import static com.mongodb.client.model.Filters.*;

public class BikePage {
    private MongoDatabase database;
    private MongoCollection<Document> bikeCollection;

    public BikePage(MongoDatabase database) {
        this.database = database;
        this.bikeCollection = database.getCollection("bikes");
    }

    public void display() {
        Scanner scanner = new Scanner(System.in);
        int choice = -1;

        while (choice != 0) {
            System.out.println("1. View all bikes");
            System.out.println("2. View bike by ID");
            System.out.println("0. Exit");
            System.out.print("Enter your choice: ");
            choice = scanner.nextInt();

            switch(choice) {
                case 1:
                    viewAllBikes();
                    break;
                case 2:
                    viewBikeById();
                    break;
                case 0:
                    System.out.println("Exiting...");
                    break;
                default:
                    System.out.println("Invalid choice.");
            }
        }

        scanner.close();
    }

    private void viewAllBikes() {
        System.out.println("Bikes:");
        for(Document doc : bikeCollection.find()) {
            System.out.println(doc.toJson());
        }
    }

    private void viewBikeById() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter bike ID: ");
        int id = scanner.nextInt();

        Document bike = bikeCollection.find(eq("_id", id)).first();

        if (bike != null) {
            System.out.println(bike.toJson());
        } else {
            System.out.println("Bike not found.");
        }
    }
}

查询页面：

import java.util.Scanner;
import org.bson.Document;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import static com.mongodb.client.model.Filters.*;

public class QueryPage {
    private MongoDatabase database;
    private MongoCollection<Document> bikeCollection;

    public QueryPage(MongoDatabase database) {
        this.database = database;
        this.bikeCollection = database.getCollection("bikes");
    }

    public void display() {
        Scanner scanner = new Scanner(System.in);
        int choice = -1;

        while (choice != 0) {
            System.out.println("1. Search bikes by name");
            System.out.println("2. Search bikes by type");
            System.out.println("0. Exit");
            System.out.print("Enter your choice: ");
            choice = scanner.nextInt();

            switch(choice) {
                case 1:
                    searchBikesByName();
                    break;
                case 2:
                    searchBikesByType();
                    break;
                case 0:
                    System.out.println("Exiting...");
                    break;
                default:
                    System.out.println("Invalid choice.");
            }
        }

        scanner.close();
    }

    private void searchBikesByName() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter bike name: ");
        String name = scanner.next();

        System.out.println("Bikes:");
        for(Document doc : bikeCollection.find(eq("name", name))) {
            System.out.println(doc.toJson());
        }
    }

    private void searchBikesByType() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter bike type: ");
        String type = scanner.next();

        System.out.println("Bikes:");
        for(Document doc : bikeCollection.find(eq("type", type))) {
            System.out.println(doc.toJson());
        }
    }
}