Question

我定义了以下节点和关系： CarMaker and Models

CarModel在多年内成为CarMaker，并且表示为MADE_IN关系的属性。
CarModel仅由一个CarMaker制作。
CarMaker可以在多年内制作多个CarModel。

我已经定义了以下类来表示节点：CarModel，CarMaker和关系MADE_IN

CarModel

@NodeEntity
public class CarModel {

    private Long id;
    private String name;
    @Relationship (type="MADE_IN", direction = Relationship.UNDIRECTED)
    private Set<MadeIn> madeIns = new HashSet<MadeIn>();
    private Set<String> years = new HashSet<String>();

    public CarModel() {     
    }

    public Long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

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


    public void addMadeIn(MadeIn madeIn) {
        System.out.println ("Found CarMaker: " + madeIn.getCarMaker());
        this.madeIns.add(madeIn);
    }

    private Set<MadeIn> getMadeIn() {
        return madeIns;     
    }

    public Set<String> getYears() {
        Iterator<MadeIn> itr = madeIns.iterator();
        while (itr.hasNext()) {
            years.add(((MadeIn) itr.next()).getYear());
        }

        Set<String> sortedYears = years.stream().collect(Collectors.toCollection(TreeSet::new));
        return sortedYears;
    }


}

的汽车制造商

public class CarMaker {

    @GraphId private Long id;
    private String name;    
    @Relationship (type="MADE_IN", direction = Relationship.UNDIRECTED)
    private Set<CarModel> carModels = new HashSet<>();


    public CarMaker() {

    }

    public Long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

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



    public Set<CarModel> getCarModels() {
        return carModels;
    }

    public void setCarModels(CarModel carModel) {
        carModels.add(carModel);

    }


}

MADE_IN

@RelationshipEntity(type="MADE_IN")
public class MadeIn {
    @GraphId private Long relationshipId;
    @Property private String year;
    @StartNode private CarMaker carMaker;
    @EndNode private CarModel carModel;


    public MadeIn() {

    }

    public MadeIn(CarMaker carMaker, CarModel carModel, String year) {
        this.carMaker = carMaker;
        this.carModel = carModel;
        this.year = year;
    }

    public Long getRelationshipId() {
        return relationshipId;
    }

    public void setCarMaker(CarMaker carMaker) {
        this.carMaker = carMaker;
    }

    public CarMaker getCarMaker() {
        return this.getCarMaker();
    }

    public void setCarModel(CarModel carModel) {
        this.carModel = carModel;
    }

    public CarModel getCarModel() {
        return this.getCarModel();
    }


    public String getYear() {
        return year;
    }

    public void setYear(String year) {
        this.year = year;
    }
}

当我提出检索CarModel的请求时，我会收到一个回复，其中包含该模型的详细信息及其生产年份：

{
    "id": 260248,
    "name": "Ulysse",
    "years": [
        "1994",
        "1995",
        "1996",
        "1997",
        "1998",
        "1999",
        "2000",
        "2001",
        "2004",
        "2005",
        "2006",
        "2007",
        "2008",
        "2009",
        "2010",
        "2011",
        "2012"
    ]
}

问题是当我尝试请求CarMaker制作的CarModel时：

{ “id”：4152072， “名字”：“宝马”， “carModels”：[] }

我注意到，如果我在MadeIn类上反转注释@StartNode和@EndNode，我会获得有关CarMaker制作的CarModel的信息，但是我将不再获得有关制作这些模型的年份的信息。

{ “id”：4152072， “名字”：“宝马”， “carModels”：[ { “id”：260852， “名字”：“120”， “年”：[] }， { “id”：261430， “名字”：“Z18”， “年”：[] }， { “id”：262044， “名字”：“L7”， “年”：[] }，

我想知道我错过了什么，或者我做错了什么？

提前感谢您的帮助。

- MD

Neo4j RelationshipEntity和Spring JPA

0 个答案: