使用 Quarkus 和 Hibernate 通过 AttributeConverter 将 JSON 更改持久保存到数据库

Question

I'm trying to persist changes to database in the following way:

Entities

I have a JPA entity with JSON data type:

@Entity
public class TestEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @NotNull
    @Convert(converter = TestConverter.class)
    @Column(name = "data", columnDefinition = "JSON")
    private TestData data;

    ...
}

With TestData entity defined like this:

public class TestData {
    private String value;

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        TestData testData = (TestData) o;
        return Objects.equals(value, testData.value);
    }

    @Override
    public int hashCode() {
        return Objects.hash(value);
    }
}

Converter

Converter for TestData is implemented like this:

@Converter
public class TestConverter implements AttributeConverter<TestData, String> {
    private static final Logger logger = LoggerFactory.getLogger(TestConverter.class);
    private static final Jsonb jsonb = JsonbBuilder.create();

    @Override
    public String convertToDatabaseColumn(TestData attribute) {
        logger.debug("To JSON: {}", attribute);
        return jsonb.toJson(attribute);
    }

    @Override
    public TestData convertToEntityAttribute(String dbData) {
        logger.debug("From JSON: {}", dbData);
        return jsonb.fromJson(dbData, TestData.class);
    }
}

Service

Finally I have a service which is trying to modify an existing entity in the database:

@ApplicationScoped
public class Service {
    private static final Logger logger = LoggerFactory.getLogger(Service.class);

    @Inject
    public EntityManager entityManager;

    @Transactional
    public void modify(Long id) {
        TestEntity entity = entityManager.find(TestEntity.class, id);
        entity.getData().setValue("new");
        logger.debug("Modified: {}", entity);
    }
}

Configuration

<property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:33003/test?sessionVariables=FOREIGN_KEY_CHECKS=0&amp;characterEncoding=UTF-8&amp;zeroDateTimeBehavior=convertToNull" />
<property name="javax.persistence.jdbc.user" value="db-user" />
<property name="javax.persistence.jdbc.password" value="db-pass" />
<property name="javax.persistence.schema-generation.database.action" value="update"/>

<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL8Dialect"/>
<property name="hibernate.show_sql" value="true"/>
<property name="hibernate.format_sql" value="true"/>
<property name="hibernate.connection.provider_disables_autocommit" value="false"/>

The Problem

The problem is that new value is not persisted to the database. Here is what I see in the log:

2019-11-30 12:19:40,065 DEBUG [org.acm.TestConverter] From JSON: {"value":"hello"}
2019-11-30 12:19:40,068 DEBUG [org.acm.TestConverter] To JSON: TestData{value='hello'}
2019-11-30 12:19:40,069 DEBUG [org.acm.TestConverter] From JSON: {"value":"hello"}
2019-11-30 12:19:40,071 DEBUG [org.acm.Service] Modified: TestEntity{id=2, data=TestData{value='new'}}

Here is the log file with hibernate logging turned on (too much to pase here so I'm posting a link): https://pastebin.com/1e3URx8W

What I've Tried

Here's some things I've tried:

• Adding entityManager.persist(entity); to the end of modify function -> no change (expected)
• Adding log entry to TestData.equals function -> no entry in the log
• Adding entity.setData(entity.getData()); to the end of modify function -> no change
• Changing JSON type to TEXT -> no change
• Manually starting and commiting transaction -> no change
• Adding temp = entity.getData(); entity.setData(null); entity.setData(temp); temp = entity.getData(); entity.setData(null); entity.setData(temp); to the end of modify function -> working the correct value is persisted to database

Is there anything I'm missing here?

Thanks

Versions

• JRE 8
• Quarkus 1.0.1.Final
• Hibernate 5.4.9.Final
• MySQL 8.0.18

Answer 1

Seems to me as if the update is pending in Hibernate's cache. If you read the entity via the EntityManager or persist and flush ( EntityManager.persistAndFlush() ) after performing entity.setData(temp) , the cache should get flushed and you should see your changes in the database.

Quote from quarkus.io :

JPA batches changes you make to your entities and sends changes (it's called flush) at the end of the transaction or before a query. This is usually a good thing as it's more efficient. But if you want to check optimistic locking failures, do object validation right away or generally want to get immediate feedback, you can force the flush operation by calling entity.flush() or even use entity.persistAndFlush() to make it a single method call.