java创建一个蔬菜类，其中包含私有属性名称、价格和重量，然 后创建方法去访问和修改的测试类

下面是一个简单的蔬菜类的Java代码，包含私有属性名称、价格和重量，以及获取和设置这些属性的方法：

public class Vegetable {
    private String name;
    private double price;
    private double weight;

    public Vegetable(String name, double price, double weight) {
        this.name = name;
        this.price = price;
        this.weight = weight;
    }

    public String getName() {
        return name;
    }

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

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public double getWeight() {
        return weight;
    }

    public void setWeight(double weight) {
        this.weight = weight;
    }
}

接下来是测试类的代码，用于创建 Vegetable 对象并设置/获取属性：

public class TestVegetable {
    public static void main(String[] args) {
        Vegetable carrot = new Vegetable("Carrot", 1.99, 0.2);
        System.out.println(carrot.getName() + " costs $" + carrot.getPrice() + " and weighs " + carrot.getWeight() + " kg.");

        carrot.setPrice(2.49);
        carrot.setWeight(0.3);
        System.out.println("After update: " + carrot.getName() + " costs $" + carrot.getPrice() + " and weighs " + carrot.getWeight() + " kg.");
    }
}

输出结果如下：

Carrot costs $1.99 and weighs 0.2 kg.
After update: Carrot costs $2.49 and weighs 0.3 kg.

在测试类中，我们首先创建一个 Vegetable 对象，然后使用 get 方法获取其属性值并打印输出。接着，我们使用 set 方法更新 Vegetable 对象的属性值，并再次打印输出。