冬眠 - 不負載的渴望協會懶實體

Question

如果我在我的項目

@Entity 
@Table(name = "application_home_screen") 
public class ApplicationHomeScreenVO implements Serializable { 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id", unique = true, nullable = false) 
    private Integer id; 

    @OneToOne(fetch = FetchType.EAGER) 
    @Cascade({ CascadeType.ALL }) 
    @JoinColumn(name="image1_id") 
    private ApplicationImageVO image1; 

    @OneToOne(fetch = FetchType.EAGER) 
    @Cascade({ CascadeType.ALL }) 
    @JoinColumn(name="image2_id") 
    private ApplicationImageVO image2; 
} 



@Entity 
@Table(name = "application_image") 
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"}) 
public class ApplicationImageVO implements Serializable { 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id", unique = true, nullable = false) 
    private Integer id; 


    @OneToOne(fetch = FetchType.LAZY, mappedBy = "image1") 
    @Cascade({ CascadeType.ALL }) 
    private ApplicationHomeScreenVO homeScreenImage1; 

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "image2") 
    @Cascade({ CascadeType.ALL }) 
    private ApplicationHomeScreenVO homeScreenImage2; 

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity1") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity1 otherEntity1; 

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity2") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity2 otherEntity2; 

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity3") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity3 otherEntity3; 

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity4") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity4 otherEntity3; 
} 

以下類當我加載ApplicationHomeVO - ID只期望圖像1和圖像2被從ApplicationImageVO類但加載情況並非如此

ApplicationImageVO類中的所有其他對象也會加載，即使它們標記爲LAZY。我預計只有ApplicationHomeScreenVO對象被加載

有什麼辦法阻止這些其他entites被加載？

謝謝 Damie

Answer 1

@OneToOne宣佈這樣被PK映射，並且它必須是預先抓取...

，您可以：

• 使其成爲@ManyToOne(fetch=FetchType.LAZY)

或

• 聲明一個外鍵列：

@OneToOne(fetch = FetchType.LAZY) @JoinColumn(name="fk") public T getT()

編輯

@Entity 
@Table(name = "application_home_screen") 
public class ApplicationHomeScreenVO implements Serializable { 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id", unique = true, nullable = false) 
    private Integer id; 

    @OneToOne(fetch = FetchType.EAGER) 
    @Cascade({ CascadeType.ALL }) 
    @JoinColumn(name="image1_id") 
    private ApplicationImageVO image1; 

    @OneToOne(fetch = FetchType.EAGER) 
    @Cascade({ CascadeType.ALL }) 
    @JoinColumn(name="image2_id") 
    private ApplicationImageVO image2; 
} 



@Entity 
@Table(name = "application_image") 
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"}) 
public class ApplicationImageVO implements Serializable { 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name = "id", unique = true, nullable = false) 
    private Integer id; 


    @OneToOne(fetch = FetchType.LAZY, mappedBy = "image1") 
    @Cascade({ CascadeType.ALL }) 
    private ApplicationHomeScreenVO homeScreenImage1; 

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "image2") 
    @Cascade({ CascadeType.ALL }) 
    private ApplicationHomeScreenVO homeScreenImage2; 

    @ManyToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity1") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity1 otherEntity1; 

    @ManyToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity2") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity2 otherEntity2; 

    @ManyToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity3") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity3 otherEntity3; 

    @ManyToOne(fetch = FetchType.LAZY, mappedBy = "otherEntity4") 
    @Cascade({ CascadeType.ALL }) 
    private OtherEntity4 otherEntity3; 
}