Erro na JPA

package autoescola.model;

import java.net.Proxy.Type;
import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;

@Entity
public class Conta 
{
   @Id
   @Column (insertable = false)
   @GeneratedValue(strategy=GenerationType.IDENTITY)
   private int id;
   private String descricao;
   @Temporal(TemporalType.DATE)
   private Date data;
   private String valor;
   private boolean tipo;  
    .  
    .
    .
}

CREATE TABLE conta
(
  id bigint NOT NULL,
  data date,
  descricao character varying(255) NOT NULL,
  valor character varying(255) NOT NULL,
  tipo boolean NOT NULL,
  CONSTRAINT pkid PRIMARY KEY (id)
)

BaseDAO<Conta> dao = new BaseDAO<Conta>();
Calendar calendario = Calendar.getInstance();
Conta conta1 = new Conta();
conta1.setDescricao("Conta 1");
conta1.setData(calendario.getTime());
conta1.setValor("R$ 500,00");
dao.create(conta1);