在构造函数中将对象作为参数传递

Toyota 和 Corolla Car car String brand 和 String model

public class Car {
    private String brand, model;

    public Car(String brand, String model) {
        this.brand = brand;
        this.model = model;
    }

    // getters and setters
}

public class Customer {
    private String name;
    private Car car;

    public Customer(String name, Car car) {
        this.name = name;
        this.car = car;
    }

    // getters and setters
}

public class Service {
    Customer customer = new Customer("John", "Toyota", "Corolla");
}