Mapping MySQL json column into JPA throws error

Question

I want to map MySQL JSON column into JPA. I did some research and I used

@Type( type = "json" )
@Column( columnDefinition = "json" )

But this throws an exception

Exception in thread "main" org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class [json]
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:348)
    at org.hibernate.boot.internal.ClassLoaderAccessImpl.classForName(ClassLoaderAccessImpl.java:62)
    at org.hibernate.cfg.annotations.SimpleValueBinder.fillSimpleValue(SimpleValueBinder.java:538)
    at org.hibernate.cfg.SetSimpleValueTypeSecondPass.doSecondPass(SetSimpleValueTypeSecondPass.java:25)
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1621)
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1579)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:278)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:858)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:885)
    at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:58)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
    at com.savemonk.ce.utility.hibernateAndJPA.JPAUtility.getEntityManagerFactory(JPAUtility.java:12)
    at com.savemonk.ce.v2.pricegraph.manager.AddNewPriceTrackRecord.addNewPriceTrackRecordTest(AddNewPriceTrackRecord.java:29)
    at com.savemonk.ce.v2.pricegraph.manager.AddNewPriceTrackRecord.main(AddNewPriceTrackRecord.java:23)
Caused by: java.lang.ClassNotFoundException: Could not load requested class : json
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl$AggregatedClassLoader.findClass(ClassLoaderServiceImpl.java:336)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:345)
    ... 14 more

I understand that @Type is hibernate's org.hibernate.annotations.Type What is the correct way to map the column in JPA?

I can post entity class if required. Any links and resources which explain about JPA + JSON-type-column would help a lot.

just adding the dependency like below , worked for me: com.vladmihalcea hibernate-types-52 2.16.2 compile — Hemant Nagpal, Jan 07 '23 at 19:01

score 2 · Answer 1 · edited Feb 05 '20 at 13:29

There is no json Type in Hibernate ORM. You can use the Hibernate Types project which offers support for JSON.

To add support for json, add the following @TypeDef annotation to your entity:

@TypeDef(name = "json", typeClass = JsonStringType.class)

You also need to add the following Maven dependency:

<dependency>
    <groupId>com.vladmihalcea</groupId>
    <artifactId>hibernate-types-52</artifactId>
    <version>${hibernate-types.version}</version>
</dependency>

Check out this article to see how you can use the JsonStringType with MySQL.

score 1 · Answer 2 · answered Nov 04 '20 at 15:52

1

Except dependency, you also need to add

@TypeDef(name = "json", typeClass = JsonStringType.class)

to one of your entities class declaration

answered Nov 04 '20 at 15:52

Javasick

2,753
1
23
35

score 0 · Answer 3 · answered Jul 22 '22 at 09:55

Add dependency

    <dependency>
        <groupId>com.vladmihalcea</groupId>
        <artifactId>hibernate-types-52</artifactId>
        <version>2.16.2</version>
        <scope>compile</scope>
    </dependency>

On above your class where you are using @Type(type = "json"). Add this:

@TypeDef(name = "json", typeClass = JsonStringType.class)

This worked for me

Mapping MySQL json column into JPA throws error

3 Answers3