Using Hibernate with Groovy

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Code Block

package demo

import javax.persistence.*
import org.hibernate.cfg.*

// javax.transaction jta.jar added manually to ivy repo
@Grapes([
    @Grab(group='org.hibernate', module='hibernate-annotations', version='3.4.0.GA'),
    @Grab(group='org.slf4j', module='slf4j-simple', version='1.4.2'),
    @Grab(group='hsqldb', module='hsqldb', version='1.8.0.7'),
    @Grab(group='javassist', module='javassist', version='3.4.GA'),
])
@Entity class Book {
    @Id @GeneratedValue(strategy = GenerationType.AUTO)
    public Long id
    public String author
    public String title
    String toString() { "$title by $author" }
}

def hibProps = [
    "hibernate.dialect": "org.hibernate.dialect.HSQLDialect",
    "hibernate.connection.driver_class": "org.hsqldb.jdbcDriver",
    "hibernate.connection.url": "jdbc:hsqldb:mem:demodb",
    "hibernate.connection.username": "sa",
    "hibernate.connection.password": "",
    "hibernate.connection.pool_size": "1",
    "hibernate.connection.autocommit": "true",
    "hibernate.cache.provider_class": "org.hibernate.cache.NoCacheProvider",
    "hibernate.hbm2ddl.auto": "create-drop",
    "hibernate.show_sql": "true",
    "hibernate.transaction.factory_class": "org.hibernate.transaction.JDBCTransactionFactory",
    "hibernate.current_session_context_class": "thread"
]

def configureHibernate(props) {
    def config = new AnnotationConfiguration()
    props.each { k, v -> config.setProperty(k, v) }
    config.addAnnotatedClass(Book.class)
    return config
}

def factory = configureHibernate(hibProps).buildSessionFactory()

// store some books
def session = factory.currentSession
def tx = session.beginTransaction()
session.save(new Book(author:'Dierk et al', title:'Groovy in Action'))
session.save(new Book(author:'Craig', title:'Spring in Action'))
tx.commit()

// find some books
session = factory.currentSession
tx = session.beginTransaction()
def books = session.createQuery("from Book").list()
println 'Found ' + books.size() + ' books:'
books.each { println it }
tx.commit()

...

No Format
Found 2 books: Groovy in Action by Dierk et al Spring in Action by Craig

We can get a little more sophisticated and show a One-to-One relationship as follows:

Code Block


@Entity class Book {
    @Id @GeneratedValue(strategy = GenerationType.AUTO)
    public Long id
    @OneToOne
    public Author author
    public String title
    String toString() { "$title by $author.name" }
}

@Entity class Author {
    @Id @GeneratedValue(strategy = GenerationType.AUTO)
    public Long id
    public String name
}

Where the configureHibernate method needs an additional line:

Code Block
... config.addAnnotatedClass(Book) // existing config.addAnnotatedClass(Author) // new ...

And creation would become:

Code Block


// store some books
def session = factory.currentSession
def tx = session.beginTransaction()
def a1 = new Author(name:'Dierk et al')
session.save(a1)
session.save(new Book(author:a1, title:'Groovy in Action'))
def a2 = new Author(name:'Craig')
session.save(a2)
session.save(new Book(author:a2, title:'Spring in Action'))
tx.commit()

Using Hibernate with Groovy

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