CODEWITHSUNDEEP
javajsonspring-bootspring-data-jpaone-to-many
Manoj Kumar
Manoj Kumar

Reputation: 159

Error in JSON result for one to many mapping in Spring-Data-Jpa

Owner Entity: PriceListItemTest.java

@JsonPropertyOrder({"pricingUOMCode","lineTypeCode","primaryPricingUOMFlag","priceListId","itemId","priceListItemId"})
@Entity
@Table(name = "QP_PRICE_LIST_ITEMS")
public class PriceListItemTest implements Serializable{

    @Column(name = "price_list_item_id")    
    private String priceListItemId;

    @Column(name = "pricing_uom_code")  
    private String pricingUOMCode; 

    @Column(name = "line_type_code")    
    private String lineTypeCode; 

    @Column(name = "primary_pricing_uom_flag")  
    private String primaryPricingUOMFlag;

    @Id
    @Column(name = "item_id")   
    private String itemId;

    @OneToMany(mappedBy = "priceListItemsTest", cascade = CascadeType.ALL)
    private List<ItemDetailTest> itemDetailsTest;

    // getters and setters
}

and Entity2 : ItemDetailTest.java

@JsonPropertyOrder({"itemNumber","inventoryItemId","organizationId"})
@Entity
@Table(name = "egp_system_items_b")
public class ItemDetailTest implements Serializable {

    @Id
    @Column(name = "inventory_item_id") 
    private String inventoryItemId; 

    @Column(name = "item_number")   
    private String itemNumber; 

    @Column(name = "organization_id")   
    private String organizationId;


//   To be used for bidirectional   
    @ManyToOne//(fetch = FetchType.LAZY)
    private PriceListItemTest priceListItemsTest;

    // getters and setters
}

The RestController is returning error while retrieving the JSON result. 

{
    "timestamp": "2018-10-23T14:05:26.248+0000",
    "status": 500,
    "error": "Internal Server Error",
    "message": "Could not write JSON: could not extract ResultSet; nested exception is com.fasterxml.jackson.databind.JsonMappingException: could not extract ResultSet (through reference chain: java.util.ArrayList[0]->com.Pricing.Pricing_App.model.PriceListItemTest[\"itemDetailsTest\"])",
    "path": "/getByItemIdTest"
}

May be the mapping oneTomany is wrong.
It is working fine if it has oneToone mapping but facing problem with OneToMany. Can someone please help me with the error?

Edit: Controller:

@RestController
public class PriceListItemControllerTest {

    @Autowired
    private PriceListItemRepositoryTest priceListItemRepositoryTest;

    @GetMapping(value="/getByItemIdTest")
    public List<PriceListItemTest> getByItemIdTest(@RequestParam("itemId") String itemId) {
        return priceListItemRepositoryTest.findByItemId(itemId);
    }

}

Upvotes: 2

Views: 8711

Answers (3)

Sachintha Hewawasam
Sachintha Hewawasam

Reputation: 851

use @JsonIgnore like in the below. problem is infinite json calls are going through your json call. to ignore that use this annotation on your ManytoOne relation. worked fine for me. 

@ManyToOne//(fetch = FetchType.LAZY)
@JsonIgnore
private PriceListItemTest priceListItemsTest;

Upvotes: 5

sam
sam

Reputation: 2004

Change your model class like below:

@Entity
@Table(name = "QP_PRICE_LIST_ITEMS")
public class PriceListItemTest implements Serializable {

    private static final long serialVersionUID = -748956247024967638L;

    @Basic
    @Column(name = "price_list_item_id")    
    private String priceListItemId;

    @Basic
    @Column(name = "pricing_uom_code")  
    private String pricingUOMCode; 

    @Basic
    @Column(name = "line_type_code")    
    private String lineTypeCode; 

    @Basic
    @Column(name = "primary_pricing_uom_flag")  
    private String primaryPricingUOMFlag;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "item_id")   
    private String itemId;

    @JsonManagedReference
    @OneToMany(mappedBy = "priceListItemsTest", cascade = CascadeType.ALL)
    private List<ItemDetailTest> itemDetailsTest;

    // getters and setters
}

and

@Entity
@Table(name = "egp_system_items_b")
public class ItemDetailTest implements Serializable {

    private static final long serialVersionUID = 8495817802073010928L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "inventory_item_id") 
    private String inventoryItemId; 

    @Basic
    @Column(name = "item_number")   
    private String itemNumber; 

    @Basic
    @Column(name = "organization_id")   
    private String organizationId;

    @JsonBackReference
    @ManyToOne
    @JoinColumn(name = "fk_item_id", nullable = false) // name of the foreign key column
    private PriceListItemTest priceListItemsTest;

    // getters and setters
}

In your JoinColumn provide the actual name of the foreign key field. It should work as Jackson will automatically serialize.

For One To many refernces you can follow these links: link1 and link2

Upvotes: 6

Simon Martinelli
Simon Martinelli

Reputation: 36103

You have a bidirectional mapping between the two entities and this would cause an infinit loop during JSON serialization.

You must ignore one of the sides using @JsonIgnore for example.

Read more about that topic here:

https://www.baeldung.com/jackson-bidirectional-relationships-and-infinite-recursion

Upvotes: 2

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