可嵌入類可以有構造函數嗎？

Question

我有一個帶有可嵌入注釋的類，當我嘗試將實例傳遞給實體時，出現異常：

org.hibernate.InstantiationException：實體沒有默認構造函數：：entity.D3

enum Figure {
    SQUARE, TRIANGLE
};

@Embeddable
public class D3 {
    float z;
    @Enumerated(EnumType.STRING)
    Figure figure;

    public D3(float z, Figure f) {
        this.z = z;
        this.figure = f;
    }
}

Answer 1

除了您定義的任何構造函數之外，它還在尋找默認構造函數（即無參數）：

@Embeddable
public class D3 {
    float z;
    @Enumerated(EnumType.STRING)
    Figure figure;

    public D3() { //I've added this
    }

    public D3(float z, Figure f) {
        this.z = z;
        this.figure = f;
    }
}