Question

我遇到了JPA的问题，我收到了很多我不需要的额外数据以及很多请求。我知道我可以通过在请求中返回DTO来解决此问题，但是随后我路由了JPA的有用性，因此我想知道是否有更好的方法来解决此问题。

例如，我有两个班。一种称为产品项目，另一种称为供应商。一个产品项目，可以具有一个ManyToOne关系的供应商。当我执行获取商品项目的获取请求时，不需要供应商的地址。我只需要名称和ID。但是，当我向供应商提出获取请求时，我确实需要与供应商有关的所有信息。除了返回没有该信息的DTO之外，还有什么方法可以指定此方法？

ProductItem.java

@Entity 
public class ProductItem {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY) 
    private Long id;
    @ManyToOne
    private Organization org;
    @ManyToOne
    private Supplier supplier;
    private String barCode;
    private String description;
    private String name;
    private Integer stock;
    private Integer caseQty;
    private BigDecimal caseCost;
    @ManyToMany(cascade=CascadeType.ALL)
    private List<Note> notes;
    @CreationTimestamp
    private LocalDateTime createdOn;
    @UpdateTimestamp
    private LocalDateTime updatedOn;

Supplier.java

@Entity 
public class Supplier {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY) 
    private Long id;
    private String name;
    @ManyToMany(cascade=CascadeType.ALL)
    private List<Note> notes;
    @ManyToOne(cascade=CascadeType.ALL)
    private Address address;
    @ManyToOne
    private Organization org;

当前获取http://localhost:8080/productitem/1

{
    "id": 1,
    "org": {
        "id": 1,
        "name": "Test",
        "address": {
             "name": "Test"
            },
        "website": null,
        "phone": null
    },
    "supplier": {
        "id": 1,
        "name": "Sams Club",
        "notes": [],
        "address": {
         "name": "Test"
        },
        "org": {
            "id": 1,
            "name": "Test",
            "address": {
             "name": "Test"
            },
            "website": null,
            "phone": null
        }
    },
    "barCode": "UPC134",
    "description": "This is description. This is description. This is description. This is description. ",
    "name": "Sunchips",
    "stock": 10,
    "caseQty": 34,
    "caseCost": 29.99,
    "notes": [
        {
            "id": 1,
            "title": "Product Item Created",
            "description": "Note created by user X on 12/16/2019 11:00PM"
        },
        {
            "id": 2,
            "title": "Product Item Updated",
            "description": "Product ITem updated stock by user X on 12/16/2019 11:00PM"
        }
    ],
    "createdOn": "2019-02-28T13:44:39",
    "updatedOn": "2019-02-28T13:44:39"
}

尝试获得http://localhost:8080/productitem/1

{
    "id": 1,
    "org": {
        "id": 1,
        "name": "Test",
        "address": null,
        "website": null,
        "phone": null
    },
    "supplier": {
        "id": 1,
        "name": "Sams Club",
    },
    "barCode": "UPC134",
    "description": "This is description. This is description. This is description. This is description. ",
    "name": "Sunchips",
    "stock": 10,
    "caseQty": 34,
    "caseCost": 29.99,
    "notes": [
        {
            "id": 1,
            "title": "Product Item Created",
            "description": "Note created by user X on 12/16/2019 11:00PM"
        },
        {
            "id": 2,
            "title": "Product Item Updated",
            "description": "Product ITem updated stock by user X on 12/16/2019 11:00PM"
        }
    ],
    "createdOn": "2019-02-28T13:44:39",
    "updatedOn": "2019-02-28T13:44:39"
}

尝试实现/当前获得http://localhost:8080/supplier/1

 {
        "id": 1,
        "name": "Sams Club",
        "notes": [],
        "address": {
         "name": "Test"
        },
        "org": {
            "id": 1,
            "name": "Test",
            "address": null,
            "website": null,
            "phone": null
        }

Answer 1

您可以使用Jackson Json Views来控制某些控制器方法的序列化/反序列化。简短示例：

查看定义：

FileName

供应商：

public class Views {
    public static class BriefSupplier {
    }

    public static class FullSupplier extends BriefSupplier {
    }
}

控制器：

@Entity 
public class Supplier {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY) 
    @JsonView(Views.BriefSupplier.class)
    private Long id;
    @JsonView(Views.BriefSupplier.class)
    private String name;
    @ManyToMany(cascade=CascadeType.ALL)
    @JsonView(Views.FullSupplier.class)
    private List<Note> notes;
    @ManyToOne(cascade=CascadeType.ALL)
    @JsonView(Views.FullSupplier.class)
    private Address address;
    @ManyToOne
    @JsonView(Views.FullSupplier.class)
    private Organization org;
}

Answer 2

除非您用@Transient专门标记，否则JPA将使用该类的所有属性：

@Transient
private String agencyName;

@Column注释纯粹是可选的，在那里您可以覆盖自动生成的列名。此外，@Column的length属性仅在自动生成表定义时使用，对运行时间没有影响。

请确保您导入的是javax.persistence.transient，而不是其他软件包。

Hibernate JPA Spring Boot忽略特定请求的JSON属性

2 个答案: