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I am migrating my Quarkus project from the classic Hibernate ORM to Hibernate Reactive and I faced a problem with JSONB field mapping.

Here is the entity:

@Entity
@TypeDef(name = JsonTypes.JSON_BIN, typeClass = JsonBinaryType::class)
class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "myEntityIdGenerator")
    @SequenceGenerator(name = "myEntityIdGenerator", sequenceName = "my_entity_id_seq", allocationSize = 10)
    var id: Long? = null

    // Usage of a plain JsonNode instead of a mapped class is intentional, 
    // as the app receives a request with raw JSON data and should store it without any processing
    @Type(type = JsonTypes.JSON_BIN)
    @NotNull
    lateinit var jsonData: JsonNode
}

The project has the io.quarkiverse.hibernatetypes:quarkus-hibernate-types:0.2.0 dependency to handle JSON types.

This code worked fine with blocking Hibernate API, but when trying to persist a MyEntity using the Hibernate Reactive, I get the following exception:

io.vertx.core.impl.NoStackTraceThrowable: Parameter at position[1] with class = [com.fasterxml.jackson.databind.node.ObjectNode] and value = [{"field1":"some value"}] can not be coerced to the expected class = [java.lang.Object] for encoding.

Is this a bug or custom types should be handled differently while using Hibernate Reactive?

Ultranium
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2 Answers2

6

Hibernate Types is not compatible with Hibernate Reactive.

But you have three options to map a Json with Hibernate Reactive:

  1. Use io.vertx.core.json.JsonObject
  2. Map it as String and use a converter
  3. Create a UserType

1. JsonObject

Example with io.vertx.core.json.JsonObject:

    @Entity
    private static class EntityWithJson {

        ...

        private JsonObject jsonObj;

...
}

You can see a working example in the repository: JsonTypeTest

2. Using a converter

Example using a converter:

class EntityWithJson {

        @Column(columnDefinition = "json")
        @Convert(converter = StringToJson.class)
        private String json;
...
}

@Converter
public class StringToJson implements AttributeConverter<String, JsonObject> {

    @Override
    public JsonObject convertToDatabaseColumn(String string) {
        if (string == null) {
            return null;
        }
        return new JsonObject(string);
    }

    @Override
    public String convertToEntityAttribute(JsonObject dbData) {

        if (dbData == null) {
            return null;
        }
        return dbData.encodePrettily();
    }
}

You can see a working example in the repository: JsonTypeTest

3. UserType

class EntityWithJson {


        @Type(type="org.example.Json")
        @Column(columnDefinition = "json")
        private JsonObject jsonObj;

}

package org.example

public class Json implements UserType {

   // ... Implementation left out for brevity
}

You can see a working example in the repository: UserJsonTypeTest

Davide D'Alto
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  • Thank you for such an exhaustive answer. The `JsonObject` field approach seems OK to me, but, unfortunately, the `io.vertx.core.json.JsonObject` does not implement `Serializable`, so when I put the `@Cacheable` annotation on my entity class, I get this exception: `ClassCastException: class io.vertx.core.json.JsonObject cannot be cast to class java.io.Serializable`. – Ultranium Aug 25 '22 at 12:34
  • I think I would map it as a string in that case – Davide D'Alto Aug 25 '22 at 12:58
  • I ended up implementing the `UserType`, handling the serialization via `assemble()` and `disassemble()` methods. Here is my solution: https://gist.github.com/Ultranium/2caaa4899ad117647f59abf690389dcd – Ultranium Aug 25 '22 at 15:44
1

To store a field with postgres type JSONB, we can use the annotation :

@JdbcTypeCode(SqlTypes.JSON)

This will automatically create the table column with JsonB data type.

Meghna Sharma
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