Autoincrementable mediante Tabla

Referencia Libro

Se usa mediante la creación de una tabla que manejara los autoincrementable para cada tabla.

CREATE TABLE id_gen (
gen_name VARCHAR(80),
gen_val INTEGER,
CONSTRAINT pk_id_gen
PRIMARY KEY (gen_name)
);
INSERT INTO id_gen (gen_name, gen_val) VALUES ('PEOPLE_GEN', 0);
INSERT INTO id_gen (gen_name, gen_val) VALUES ('HISTORIAL_GEN', 0);



  create table PEOPLE(
   PEOPLEID NUMBER NOT NULL,
     DESCRIPCION VARCHAR(100)  ,
     "FECHA" DATE,
      CONSTRAINT PEOPLEPK PRIMARY KEY (PEOPLEID)
    );

Definimos la entidad

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.peopleinmotion.horizonreinicioremotoejb.entity;

import java.io.Serializable;
import java.util.Date;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.persistence.TableGenerator;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.validation.constraints.NotNull;

/**
 *
 * @author avbravo
 */
@Entity
@Table(name = "PEOPLE")
@NamedQueries({
   @NamedQuery(name = "PEOPLE.findAll", query = "SELECT p FROM People p"),
   @NamedQuery(name = "PEOPLE.findByPEOPLEId", query = "SELECT p FROM People p WHERE p.PEOPLEID = :PEOPLEID"),
   @NamedQuery(name = "PEOPLE.findByDescripcion", query = "SELECT p FROM People p WHERE p.DESCRIPCION = :DESCRIPCION")})
public class People implements Serializable {

    private static final long serialVersionUID = 1L;
    // @Max(value=?)  @Min(value=?)//if you know range of your decimal fields consider using these annotations to enforce field validation


    @TableGenerator(name = "PEOPLE_GEN",
            table = "ID_GEN",
            pkColumnName = "GEN_NAME",
            valueColumnName = "GEN_VAL",
            pkColumnValue = "PEOPLE_GEN",
            initialValue = 10000,
            allocationSize = 100)
    @GeneratedValue(generator = "PEOPLE_GEN")
    @Id
   
    @Basic(optional = false)
     @NotNull
    @Column(name = "PEOPLEID")
    private Integer PEOPLEID;

    @Column(name = "DESCRIPCION")
    private String DESCRIPCION;
    
    @Column(name="FECHA")
       @Temporal(TemporalType.TIMESTAMP)
    private Date FECHA;

    public People() {
    }

    public People(Integer PEOPLEID) {
        this.PEOPLEID = PEOPLEID;
    }

    public Date getFECHA() {
        return FECHA;
    }

    public void setFECHA(Date FECHA) {
        this.FECHA = FECHA;
    }
    
    

    public Integer getPEOPLEID() {
        return PEOPLEID;
    }

    public void setPEOPLEID(Integer PEOPLEID) {
        this.PEOPLEID = PEOPLEID;
    }

    public String getDESCRIPCION() {
        return DESCRIPCION;
    }

    public void setDESCRIPCION(String DESCRIPCION) {
        this.DESCRIPCION = DESCRIPCION;
    }

    
   

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (PEOPLEID != null ? PEOPLEID.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // PEOPLEx: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof People)) {
            return false;
        }
        People other = (People) object;
        if ((this.PEOPLEID == null && other.PEOPLEID != null) || (this.PEOPLEID != null && !this.PEOPLEID.equals(other.PEOPLEID))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "com.peopleinmotion.mavenproject1.PEOPLE[ PEOPLEID=" + PEOPLEID + " ]";
    }

}

Definir el repositorio

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.peopleinmotion.horizonreinicioremotoejb.repository;

import com.peopleinmotion.horizonreinicioremotoejb.entity.People;

import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

/**
 *
 * @author avbravo
 */
@Stateless
public class PeopleFacade extends AbstractFacade<People> {

    @PersistenceContext(unitName = "com.people-inmotion_horizonreinicioremotoejb_ejb_1.0-SNAPSHOTPU")
    private EntityManager em;

    @Override
    protected EntityManager getEntityManager() {
        return em;
    }

    public PeopleFacade() {
        super(People.class);
    }
    
    public List<People> findByDescripcion(String descripcion) {
        Query query = em.createNamedQuery("PEOPLE.findByDescripcion");
        return query.setParameter("descripcion",descripcion).getResultList();
    }

   

  
    
}

En el controller

   People people = new People();   
//            em.getTransaction().begin();

           people.setDESCRIPCION(JsfUtil.generateUniqueID());
            people.setFECHA(DateUtil.fechaHoraActual());
           
            peopleFacade.create(people);