"Hibernate 不在数据库中保存对象？"

Question

I have the following problem, when trying to insert an object in the database Hibernate gets stuck, no error returned, the object is not saved correctly.

Debugging it I found out that it hangs at

Hibernate: select nextval('hibernate_sequence')

I am using PostgreSQL as a database.

My configuration file:

<hibernate-mapping>
    <class name="src.MyClass" table="MyClass">

    <cache usage="read-write"/>

    <id name="id" column="classid">
        <generator class="native" />
    </id>

    <property name="name" column="name" not-null="true" unique="true" length="160"/>

</class>
</hibernate-mapping>

@Override
public void save( Myclass mc)
{
    Session session = sessionFactory.getCurrentSession();

    session.save( mc);
}

The SELECT part works.

I'm not sure what I'm missing. Also using native SQL Insert command, it works.

Answer 1

I did'nt see you that flushing your session

Session session = sessionFactory.openSession();
session.save(mc);
session.flush();
session.close();

But most preferable is

Session session = factory.openSession();
    Transaction tx = null;
    try {
        tx = session.beginTransaction();
        session.save(mc);
        tx.commit(); // Flush happens automatically
    }
    catch (RuntimeException e) {
        tx.rollback();
        throw e; // or display error message
    }
    finally {
        session.close();
    }

Answer 2

Kotlin makes things easier:

import org.hibernate.Session

val session: Session get() = sessionFactory.openSession()

fun Session.executeTransaction(action: (Session) -> Unit) = use {
    val transaction = it.beginTransaction()
    action(it)
    transaction.commit()
}

fun <T> T.saveToDb() = session.executeTransaction { it.save(this) }

fun <T> T.updateAtDb() = session.executeTransaction { it.update(this) }

fun <T> T.deleteFromDb() = session.executeTransaction { it.delete(this) }