Models

package br.com.whitewinter.model;

import java.io.Serializable;
import java.util.List;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import org.hibernate.validator.Email;
import org.hibernate.validator.Length;
import org.hibernate.validator.NotEmpty;
import org.hibernate.validator.NotNull;

import br.com.caelum.vraptor.ioc.Component;

@Entity
@Component
@Table(name = "cliente")
public class Cliente {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @OneToOne(fetch = FetchType.EAGER)
    @NotNull(message = "Usuario não foi carregado corretamente. Tente preencher os campos novamente. Caso o erro persista, entre em contato com o administrador do sistema.")
    @JoinColumn(name = "usuario_id", nullable = false)
    private Usuario usuario;

    // gets e sets
}

// usuario
package br.com.whitewinter.model;

import java.io.Serializable;
import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;
import org.hibernate.validator.Length;
import org.hibernate.validator.NotEmpty;
import org.hibernate.validator.NotNull;
import org.hibernate.validator.Valid;

import br.com.caelum.vraptor.ioc.Component;

@Entity
@Component
@Table(name = "usuario")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Usuario {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @NotNull(message = "Usuario Master não foi carregado corretamente. Tente preencher os campos novamente. Caso o erro persista, entre em contato com o administrador do sistema.")
    @JoinColumn(name = "usuario_master_id", nullable = false)
    private UsuarioMaster usuarioMaster;

    // gets e sets
}

// usuario master

package br.com.whitewinter.model;

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.Table;

import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;
import org.hibernate.validator.Length;
import org.hibernate.validator.NotEmpty;

import br.com.caelum.vraptor.ioc.Component;

@Entity
@Component
@Table(name = "usuario_master")
@Cache(usage = CacheConcurrencyStrategy.READ_ONLY)
public class UsuarioMaster  {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @NotEmpty(message = "Campo 'nome' deve ser preenchido.")
    @Length(max = 50, message = "Campo 'nome' ultrapassa o tamanho máximo de 50 caracteres.")
    @Column(nullable = false, length = 50)
    private String nome;

    // gets e sets
}