Erro ao salvar pela segunda vez no banco(Resolvido)

[Dfodani]

Alguém me ajuda por favor o que sera que esta acontecendo esta dando este erro , a primeira vez salva sem erros mas a segunda vez da pau

dez 30, 2019 10:41:58 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Error executing DDL “create table Cidade (codigo int8 not null, nome varchar(50) not null, estado_codigo int8 not null, primary key (codigo))” via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL “create table Cidade (codigo int8 not null, nome varchar(50) not null, estado_codigo int8 not null, primary key (codigo))” via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlString(AbstractSchemaMigrator.java:559)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlStrings(AbstractSchemaMigrator.java:504)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.createTable(AbstractSchemaMigrator.java:277)
at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:71)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72)
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:310)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
at com.meson.sistemavendas.util.HibernateUtil.criarFabricaDeSessoes(HibernateUtil.java:43)
at com.meson.sistemavendas.util.HibernateUtil.(HibernateUtil.java:16)
at com.meson.sistemavendas.Tela.TelaEstado$2.actionPerformed(TelaEstado.java:112)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.postgresql.util.PSQLException: ERROR: relation “cidade” already exists
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:562)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:406)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:398)
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54)
… 50 more

Hibernate: create table Estado (codigo int8 not null, nome varchar(50) not null, sigla varchar(2) not null, primary key (codigo))
dez 30, 2019 10:41:58 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Error executing DDL “create table Estado (codigo int8 not null, nome varchar(50) not null, sigla varchar(2) not null, primary key (codigo))” via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL “create table Estado (codigo int8 not null, nome varchar(50) not null, sigla varchar(2) not null, primary key (codigo))” via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlString(AbstractSchemaMigrator.java:559)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlStrings(AbstractSchemaMigrator.java:504)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.createTable(AbstractSchemaMigrator.java:277)
at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:71)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72)
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:310)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
at com.meson.sistemavendas.util.HibernateUtil.criarFabricaDeSessoes(HibernateUtil.java:43)
at com.meson.sistemavendas.util.HibernateUtil.(HibernateUtil.java:16)
at com.meson.sistemavendas.Tela.TelaEstado$2.actionPerformed(TelaEstado.java:112)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.postgresql.util.PSQLException: ERROR: relation “estado” already exists
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:562)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:406)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:398)
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54)
… 50 more

Hibernate: alter table Cidade add constraint FKqed4xf4didnaoj5gas05bjwd9 foreign key (estado_codigo) references Estado
dez 30, 2019 10:41:58 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Error executing DDL “alter table Cidade add constraint FKqed4xf4didnaoj5gas05bjwd9 foreign key (estado_codigo) references Estado” via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL “alter table Cidade add constraint FKqed4xf4didnaoj5gas05bjwd9 foreign key (estado_codigo) references Estado” via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlString(AbstractSchemaMigrator.java:559)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlStrings(AbstractSchemaMigrator.java:504)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applyForeignKeys(AbstractSchemaMigrator.java:433)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:249)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72)
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:310)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
at com.meson.sistemavendas.util.HibernateUtil.criarFabricaDeSessoes(HibernateUtil.java:43)
at com.meson.sistemavendas.util.HibernateUtil.(HibernateUtil.java:16)
at com.meson.sistemavendas.Tela.TelaEstado$2.actionPerformed(TelaEstado.java:112)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.postgresql.util.PSQLException: ERROR: constraint “fkqed4xf4didnaoj5gas05bjwd9” for relation “cidade” already exists
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:562)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:406)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:398)
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54)
… 49 more

Hibernate: select nextval (‘hibernate_sequence’)
Hibernate: insert into Estado (nome, sigla, codigo) values (?, ?, ?)

minha classe hibernate.cfg

<?xml version="1.0" encoding="UTF-8"?> org.postgresql.Driver postgres jdbc:postgresql://localhost:5432/sistema postgres org.hibernate.dialect.PostgreSQLDialect true false update

</session-factory>

minha classe hibernate.util

package com.meson.sistemavendas.util;
import java.sql.Connection;
import java.sql.SQLException;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.jdbc.ReturningWork;
import org.hibernate.service.ServiceRegistry;

import com.meson.sistemavendas.Domain.Cidade;
import com.meson.sistemavendas.Domain.Estado;

public class HibernateUtil {
private static SessionFactory fabricaDeSessoes = criarFabricaDeSessoes();

public static SessionFactory getFabricaDeSessoes() {
	return fabricaDeSessoes;
}

public static Connection getConexao(){
	Session sessao = fabricaDeSessoes.openSession();
	
	Connection conexao = sessao.doReturningWork(new ReturningWork<Connection>() {
		@Override
		public Connection execute(Connection conn) throws SQLException {
			return conn;
		}
	});
	
	return conexao;
}

private static SessionFactory criarFabricaDeSessoes() {
	try {
		Configuration configuracao = new Configuration().configure();
                    configuracao.addAnnotatedClass(Estado.class);
                  configuracao.addAnnotatedClass(Cidade.class);
		
		ServiceRegistry registro = new StandardServiceRegistryBuilder().applySettings(configuracao.getProperties()).build();
		
		SessionFactory fabrica = configuracao.buildSessionFactory(registro);
		
		return fabrica;
	} catch (Throwable ex) {
		System.err.println("A fábrica de sessões não pode ser criada." + ex);
		throw new ExceptionInInitializerError(ex);
	}
}

}

[filipecaldas]

WARN: GenerationTarget encountered exception accepting command : Error executing DDL “create table Cidade (codigo int8 not null, nome varchar(50) not null, estado_codigo int8 not null, primary key (codigo))” via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL “create table Cidade (codigo int8 not null, nome varchar(50) not null, estado_codigo int8 not null, primary key (codigo))” via JDBC Statement

Eu imagino que possa ser porque você não fez a primaty key da sua tabela cidade ser auto incrementável , assim quando você cria o primeiro ta tudo bem,mas quando cria o segundo pode estar repetindo a primary key do primeiro e dando erro, dependendo do banco de dados que está usando você pode colocar a primary key como auto incrementável, por exemple em postgresql seria o comando SERIAL, ai vai de cada sgbd, espero que seja esse o problema.

[Dfodani]

olha minhas tabelas são criadas assim estou usando postgresql

a cidade

package com.meson.sistemavendas.Domain;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;

/**
 *
 * @author Dani
 */
@SuppressWarnings("serial")
@Entity
public class Cidade implements Serializable{
	@Column(length = 50, nullable = false)
	private String nome;
	
	@ManyToOne
	@JoinColumn(nullable = false)
	private Estado estado;
        @GeneratedValue(strategy = GenerationType.AUTO)
        @Id
	private Long codigo;

	public Long getCodigo() {
		return codigo;
	}

	public void setCodigo(Long codigo) {
		this.codigo = codigo;
	}

	@Override
	public String toString() {
		return String.format("%s[codigo=%d]", getClass().getSimpleName(), getCodigo());
	}

	public String getNome() {
		return nome;
	}

	public void setNome(String nome) {
		this.nome = nome;
	}

	public Estado getEstado() {
		return estado;
	}

	public void setEstado(Estado estado) {
		this.estado = estado;
	}
}

tabela estado

package com.meson.sistemavendas.Domain;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@SuppressWarnings(“serial”)
@Entity
public class Estado implements Serializable {
@GeneratedValue(strategy = GenerationType.AUTO)
@Id
private Long codigo;
@Column(length = 2, nullable = false)
private String sigla;

@Column(length = 50, nullable = false)
private String nome;
    
    public Long getCodigo() {
	return codigo;
}

public void setCodigo(Long codigo) {
	this.codigo = codigo;
}

public String toString() {
	return String.format("%s[codigo=%d]", getClass().getSimpleName(), getCodigo());
}

public String getSigla() {
	return sigla;
}

public void setSigla(String sigla) {
	this.sigla = sigla;
}

public String getNome() {
	return nome;
}

public void setNome(String nome) {
	this.nome = nome;
}

}

[Dfodani]

alterei os nomes mas nao deu nao

[Dfodani]

se voce puder me ajudar eu agradeco pq nao estou enxergando o que esta errado

[PedreiroDeSoftware]

Caused by: org.postgresql.util.PSQLException: ERROR: relation “cidade” already exists

Não entendo muito de hibernate.
Mas pelo erro percebe-se que está tentando criar tabelas que já existem no banco de dados.

O correto seria criar se não existir.
Seria algo como:

CREATE TABLE IF NOT EXISTS cidade (
   ...
);

Talvez ajude, veja:

Hibernate recriando as tabelas existentes | Fórum Alura

Hibernate recriando tabelas?

Boa tarde pessoal!!! Estou tentando aprender a usar o hibernate e fazendo alguns testes dentro do ambiente web com o tomcat. Criei algumas tabelas e mapeamentos, porém percebi que ao iniciar o contexto, “algumas” dessas tabelas tem seus registros totalmente apagados. Então apaguei do banco de dados estas tabelas e ao iniciar a aplicação elas foram recriadas novamente!!! *Eu segui o tutorial que vem no download do hibernate, onde ensina a criar uma classe utilitária que é instanciada ao iniciar…

How to create database schema in hibernate first time and further update it in case of schema modification?

[Dfodani]

seria no hibernate.cfg pior é que eu coloquei update para atualizar tabela é que no codigo nao estou enxergando onde estou recriando o problema era que era pra dar certo pq ja tinha recriado o hibernate.cfg.xml segue ele ai

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.password">postgres</property>
        <property name="hibernate.connection.url">jdbc:postgresql://localhost:5432/sistema</property>
        <property name="hibernate.connection.username">postgres</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.format_sql">false</property>
        <property name="hbm2ddl.auto">update</property>
         
      
         
    </session-factory>
</hibernate-configuration>

classe hibernate.util

package com.meson.sistemavendas.util;
import java.sql.Connection;
import java.sql.SQLException;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.jdbc.ReturningWork;
import org.hibernate.service.ServiceRegistry;

import com.meson.sistemavendas.Domain.Cidade;
import com.meson.sistemavendas.Domain.Estado;

public class HibernateUtil {
	private static SessionFactory fabricaDeSessoes = criarFabricaDeSessoes();

	public static SessionFactory getFabricaDeSessoes() {
		return fabricaDeSessoes;
	}
	
	public static Connection getConexao(){
		Session sessao = fabricaDeSessoes.openSession();
		
		Connection conexao = sessao.doReturningWork(new ReturningWork<Connection>() {
			@Override
			public Connection execute(Connection conn) throws SQLException {
				return conn;
			}
		});
		
		return conexao;
	}

	private static SessionFactory criarFabricaDeSessoes() {
		try {
			Configuration configuracao = new Configuration().configure();
                        configuracao.addAnnotatedClass(Estado.class);
                      configuracao.addAnnotatedClass(Cidade.class);
			
			ServiceRegistry registro = new StandardServiceRegistryBuilder().applySettings(configuracao.getProperties()).build();
			
			SessionFactory fabrica = configuracao.buildSessionFactory(registro);
			
			return fabrica;
		} catch (Throwable ex) {
			System.err.println("A fábrica de sessões não pode ser criada." + ex);
			throw new ExceptionInInitializerError(ex);
		}
	}
}

no netbeans havia dado certo ai agora alterei a ide pro eclipse ai deu monte de pau kkkkk
vou ler seu artigo pra ver o que posso fazer aqui rs

[Dfodani]

Deu certo removendo esta linha

update

so que em outras versões de eclipse nao acontecia esse problema vai entender

[Dfodani]

<property name="hbm2ddl.auto">update</property>