我在做一个小的springrestapi项目。我有两个类，它们表示数据库中的两个表。我在要从中检索数据的对象中有一个@onetomanyMap。现在我检索所有嵌套对象，但是我想要的是能够通过int datestamp变量（在我的类中是一个声明为“utcs”的历元）限制嵌套对象的数量。我天真地认为，粗糙的政策可以帮助我，但现在我明白我错了。我希望能够在我的存储库中执行以下操作：

@Repository
public interface TypeRepository extends CrudRepository<Type, Integer> {
    List<Type> findByDataUtcsGreaterThan(int utcs);
}

这就是我想要的json结构，以及它现在的样子。但是如何限制数据对象的数量呢？

[
    {
        "typeKey": "Queue",
        "uomId": 1,
        "data": [
            {
                "value": 11,
                "utcs": 1605840300
            },
            {
                "value": 15,
                "utcs": 1605840360
            },
            {
                "value": 22,
                "utcs": 1605840420
            }
        ]
    },
    {
        "typeKey": "Unroutable",
        "uomId": 1,
        "data": [
            {
                "value": 196,
                "utcs": 1605840300
            },
            {
                "value": 196,
                "utcs": 1605840360
            },
            {
                "value": 196,
                "utcs": 1605840420
            }
        ]
    }
]

具有嵌套对象@onetomany的（type）对象类

@Entity
@Table(name = "SYSTEMSTATSTYPE")
public class Type {
    @Id
    @Column(name = "ID")
    private int id;
    @Column(name = "TYPEKEY")
    private String typeKey;
    @Column(name = "UOMID")
    private int uomId;

    @OneToMany(mappedBy = "type", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    private List<Data> data = new ArrayList<>();

    public Type() {
        super();
    }

    public Type(String typeKey, int uomId) {
        this.typeKey = typeKey;
        this.uomId = uomId;
    }

    // Getters and setters
}

（数据）对象类@manytone

@Entity
@Table(name = "SYSTEMSTATSDATA")
public class Data {
    @Id
    @Column(name = "ID")
    private int id;
    @Column(name = "VALUE")
    private int value;
    @Column(name = "UTCS")
    private int utcs;

    @JsonIgnore
    @ManyToOne
    @JoinColumn(name = "TYPEID")
    private Type type;

    public Data() {
        super();
    }

    public Data(int value, int utcs, Type type) {
        super();
        this.value = value;
        this.utcs = utcs;
        this.type = type;
    }
    // Getters and setters
}