Hibernate annotations

Assuntos Gerais
#1

to com um exemplo q tah me dando muita dor de cabeça… ja vi q esse problema muita gente ja teve so que em situacoes diferente…

o erro é: Hibernate Dialect must be explicitly set e Hibernate Dialect must be explicitly set!

e que mesmo eu tirando o hibernate.cfg.xml ou persistence.xml o erro eh o mesmo…

os diretorios estao da seguinte forma:

hello
Helloworld.java
Message.java
META-INF
persistence.xml

as classes sao essas:

package hello;

import javax.persistence.*;

@Entity
@Table(name = “MESSAGES”)
public class Message {

@Id @GeneratedValue
@Column(name = “MESSAGE_ID”)
private Long id;

@Column(name = “MESSAGE_TEXT”)
private String text;

@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = “NEXT_MESSAGE_ID”)
private Message nextMessage;

private Message() {}

public Message(String text) {
this.text = text;
}

public Long getId() {
return id;
}

private void setId(Long id) {
this.id = id;
}

public String getText() {
return text;
}

public void setText(String text) {
this.text = text;
}

public Message getNextMessage() {
return nextMessage;
}

public void setNextMessage(Message nextMessage) {
this.nextMessage = nextMessage;
}
}

package hello;

import java.util.;
import javax.persistence.;

public class HelloWorld {

public static void main(String[] args) {
	// Start EntityManagerFactory
	EntityManagerFactory emf = Persistence.createEntityManagerFactory("helloworld");
	
	// First unit of work
	EntityManager em = emf.createEntityManager();
	EntityTransaction tx = em.getTransaction();
	tx.begin();
	
	Message message = new Message("Hello World");
	em.persist(message);
	tx.commit();
	em.close();
	
	// Second unit of work
	EntityManager newEm = emf.createEntityManager();
	EntityTransaction newTx = newEm.getTransaction();
	newTx.begin();
	
	List messages = newEm.createQuery("select m from Message m order by m.text asc").getResultList();
	System.out.println( messages.size() + " message(s) found" );
	
	for (Object m : messages) {
	Message loadedMsg = (Message) m;
	System.out.println(loadedMsg.getText());
	}
	
	newTx.commit();
	newEm.close();
	
	// Shutting down the application
	emf.close();
}

}

e o persistence.xml:

org.hibernate.ejb.HibernatePersistence 
<class>hello.Message</class>

<properties>
	<property name="hibernate.archive.autodetection"
	value="class, hbm"/>
	
	<property name="hibernate.show_sql" value="true"/>
	
	<property name="hibernate.format_sql" value="true"/>
	
	<property name="hibernate.connection.driver_class"
	value="com.mysql.jdbc.Driver"/>
	
	<property name="hibernate.connection.url"
	value="jdbc:mysql://localhost/banco?autoReconnect=true"/>
	
	<property name="hibernate.connection.username"
	value="root"/>
	
	<property name="hibernate.c3p0.min_size"
	value="5"/>
	
	<property name="hibernate.c3p0.max_size"
	value="20"/>
	
	<property name="hibernate.c3p0.timeout"
	value="300"/>
	
	<property name="hibernate.c3p0.max_statements"
	value="50"/>
	
	<property name="hibernate.c3p0.idle_test_period"
	value="3000"/>
	
	<property name="hibernate.dialect"
	value="org.hibernate.dialect.MySQLDialect"/>
	
	<property name="hibernate.hbm2ddl.auto" value="create"/>
</properties>

ja coloquei o persitence em tudo q eh canto masi nao tem jeito… esse exemplo eh adaptado do Java persitence with hibernate…

alguem ja passou por isso? pode me dar uma luz?

#2