Not-null property references a null or transient value + Excluir dados Associados

posta o ManagedBean e a Classe ae pra ajudar

public class TarefaProgHandler {

private Tarefaprogramada tp;
private List<Tarefaprogramada> tarefaProgListagem;
private String status;
private Tarefaprogramada tps;

public TarefaProgHandler() {
    tp = new Tarefaprogramada();
    status = "incluindo";
    carregaLista();
}

public String Novo() {
    tp = new Tarefaprogramada();
    status = "incluindo";
    return "sucesso";
}

public String Cadastrar() {
    tp = new Tarefaprogramada();
    status = "incluindo";
    return "cadastroTp";
}

public String MovimentarTp() {
    status = "incluindo";
    return "atendimentoTp";
}

public String getStatus() {
    return status;
}

public void setStatus(String status) {
    this.status = status;
}

public List<Tarefaprogramada> getTarefaProgListagem() {
    return tarefaProgListagem;
}

public void setTarefaProgListagem(List<Tarefaprogramada> tarefaProgListagem) {
    this.tarefaProgListagem = tarefaProgListagem;
}

public Tarefaprogramada getTp() {
    return tp;
}

public void setTp(Tarefaprogramada tp) {
    this.tp = tp;
}

private void carregaLista() {
    Session s = HibernateUtil.currentSession();
    Dao<Tarefaprogramada> dao = new Dao<Tarefaprogramada>(s, Tarefaprogramada.class);
    this.tarefaProgListagem = dao.list();
}

public String salve() {
    Session s = HibernateUtil.currentSession();
    Dao<Tarefaprogramada> dao = new Dao<Tarefaprogramada>(s, Tarefaprogramada.class);

    if (status.equals("incluindo")) {
        dao.save(tp);
        tarefaProgListagem.add(tp);
    } else {
        dao.merge(tp);
        carregaLista();
    }

    return "sucesso";
}

public String busca() {
    HttpServletRequest req =
            (HttpServletRequest) FacesContext.getCurrentInstance().
            getExternalContext().getRequest();

    Session s = HibernateUtil.currentSession();
    Dao<Tarefaprogramada> dao = new Dao<Tarefaprogramada>(s, Tarefaprogramada.class);

    tp = dao.load(Integer.parseInt(req.getParameter("linkId")));
    status = "alterando";
    return "visualizarChamado";
}


public String exclua() {
    HttpServletRequest req =
            (HttpServletRequest) FacesContext.getCurrentInstance().
            getExternalContext().getRequest();
    Session s = HibernateUtil.currentSession();

    Dao<Tarefaprogramada> dao = new Dao<Tarefaprogramada>(s, Tarefaprogramada.class);

    tp = dao.load(Integer.parseInt(req.getParameter("linkId")));
    dao.delete(tp);
    carregaLista();
    return "mesma_pagina";
}

}

classe associada
package modelo.entidade;

import java.io.Serializable;

import java.util.ArrayList;

import java.util.Date;

import javax.persistence.Basic;

import javax.persistence.CascadeType;

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.Lob;

import javax.persistence.ManyToOne;

import javax.persistence.Table;

import javax.persistence.Temporal;

import javax.persistence.TemporalType;

/**
*

• @author Paulo
  
  */
  
  @Entity
  
  @Table(name = “TP_HISTORICO”)
  
  public class TpHistorico implements Serializable {
  

  private static final long serialVersionUID = 1L;
  
  @Id
  
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  
  <a class="mention" href="/u/basic">@Basic</a>(optional = false)
  
  @Column(name = “TPH_ID”)
  
  private Integer tphId;
  
  <a class="mention" href="/u/basic">@Basic</a>(optional = false)
  
  @Column(name = “TPH_DATAINICIO”)
  
  @Temporal(TemporalType.TIMESTAMP)
  
  private Date tphDatainicio;
  
  <a class="mention" href="/u/basic">@Basic</a>(optional = false)
  
  @Column(name = “TPH_DATATERMINO”)
  
  @Temporal(TemporalType.TIMESTAMP)
  
  private Date tphDatatermino;
  
  <a class="mention" href="/u/basic">@Basic</a>(optional = true)
  
  <a class="mention" href="/u/lob">@Lob</a>
  
  @Column(name = “TPH_DESCRICAO”)
  
  private String tphDescricao;
  
  @JoinColumn(name = “FASE_ID”, referencedColumnName = “FASE_ID”)
  
  @ManyToOne(optional = false)
  
  private Fase tpHfaseId;
  
  @JoinColumn(name = “TP_ID”, referencedColumnName = “TP_ID”)
  
  @ManyToOne(optional = false)
  
  private Tarefaprogramada tphTpId;
  
  @JoinColumn(name = “USUARIO_ID”, referencedColumnName = “USUARIO_ID”)
  
  @ManyToOne(optional = false)
  
  private Usuario usuarioIdHistorico;
  

  public TpHistorico() {
  
  tphId = 0;
  
  tphDatainicio = new Date();
  
  tphDatatermino = new Date();
  
  tphDescricao = “”;
  

  tphTpId = new Tarefaprogramada();
   tpHfaseId = new Fase();
   usuarioIdHistorico = new Usuario();
   tpHfaseId = new Fase();
  

  }

  public TpHistorico(Integer tphId) {
  
  this.tphId = tphId;
  
  }
  

  public TpHistorico(Integer tphId, Date tphDatainicio, Date tphDatatermino, String tphDescricao, Fase tpHfaseId, Tarefaprogramada tphTpId, Usuario usuarioIdHistorico) {
  
  this.tphId = tphId;
  
  this.tphDatainicio = tphDatainicio;
  
  this.tphDatatermino = tphDatatermino;
  
  this.tphDescricao = tphDescricao;
  
  this.tpHfaseId = tpHfaseId;
  
  this.tphTpId = tphTpId;
  
  this.usuarioIdHistorico = usuarioIdHistorico;
  
  }
  

  public Integer getTphId() {
  
  return tphId;
  
  }
  

  public void setTphId(Integer tphId) {
  
  this.tphId = tphId;
  
  }
  

  public Date getTphDatainicio() {
  
  return tphDatainicio;
  
  }
  

  public void setTphDatainicio(Date tphDatainicio) {
  
  this.tphDatainicio = tphDatainicio;
  
  }
  

  public Date getTphDatatermino() {
  
  return tphDatatermino;
  
  }
  

  public void setTphDatatermino(Date tphDatatermino) {
  
  this.tphDatatermino = tphDatatermino;
  
  }
  

  public String getTphDescricao() {
  
  return tphDescricao;
  
  }
  

  public void setTphDescricao(String tphDescricao) {
  
  this.tphDescricao = tphDescricao;
  
  }
  

  public Fase getFaseId() {
  
  return tpHfaseId;
  
  }
  

  public void setFaseId(Fase faseId) {
  
  this.tpHfaseId = faseId;
  
  }
  

  public Tarefaprogramada getTpId() {
  
  return tphTpId;
  
  }
  

  public void setTpId(Tarefaprogramada tpId) {
  
  this.tphTpId = tpId;
  
  }
  

  public Usuario getUsuarioIdHistorico() {
  
  return usuarioIdHistorico;
  
  }
  

  public void setUsuarioIdHistorico(Usuario usuarioIdHistorico) {
  
  this.usuarioIdHistorico = usuarioIdHistorico;
  
  }
  

  public Fase getTpHfaseId() {
  
  return tpHfaseId;
  
  }
  

  public void setTpHfaseId(Fase tpHfaseId) {
  
  this.tpHfaseId = tpHfaseId;
  
  }
  

  public Tarefaprogramada getTphTpId() {
  
  return tphTpId;
  
  }
  

  public void setTphTpId(Tarefaprogramada tphTpId) {
  
  this.tphTpId = tphTpId;
  
  }
  

  <a class="mention" href="/u/override">@Override</a>
  
  public int hashCode() {
  
  int hash = 0;
  
  hash += (tphId != null ? tphId.hashCode() : 0);
  
  return hash;
  
  }
  

  <a class="mention" href="/u/override">@Override</a>
  
  public boolean equals(Object object) {
  
  // TODO: Warning - this method won’t work in the case the id fields are not set
  
  if (!(object instanceof TpHistorico)) {
  
  return false;
  
  }
  
  TpHistorico other = (TpHistorico) object;
  
  if ((this.tphId == null && other.tphId != null) || (this.tphId != null && !this.tphId.equals(other.tphId))) {
  
  return false;
  
  }
  
  return true;
  
  }
  

  <a class="mention" href="/u/override">@Override</a>
  
  public String toString() {
  
  return “modelo.entidade.TpHistorico[tphId=” + tphId + “]”;
  
  }
  
  }