Erro no Hibernate

if (funcao.equals("remove")) {
            String id = request.getParameter("id");
            int idint = Integer.parseInt(id.trim());          
            pesquisaDao = em.find(Pesquisa.class, idint); 

            System.err.println("Pesquisa: " + id);
            try {
                em.getTransaction().begin();

            em.remove(pesquisaDao);            ////////////////////////////////////////////////////////////////////////////////

                em.getTransaction().commit();
            } catch (Exception e) {
                System.err.println("Erro :" + e.getMessage());
            }

package entidades;

import java.io.Serializable;
import java.util.Collection;
import java.util.Date;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;

/**
 *
 * @author danielti
 */
@Entity
@Table(name = "Pesquisa")
@NamedQueries({@NamedQuery(name = "Pesquisa.findById", query = "SELECT p FROM Pesquisa p WHERE p.id = :id"), @NamedQuery(name = "Pesquisa.findByNome", query = "SELECT p FROM Pesquisa p WHERE p.nome = :nome"), @NamedQuery(name = "Pesquisa.findByDescricao", query = "SELECT p FROM Pesquisa p WHERE p.descricao = :descricao"), @NamedQuery(name = "Pesquisa.findByDataInicio", query = "SELECT p FROM Pesquisa p WHERE p.dataInicio = :dataInicio"), @NamedQuery(name = "Pesquisa.findByHoraInicio", query = "SELECT p FROM Pesquisa p WHERE p.horaInicio = :horaInicio"), @NamedQuery(name = "Pesquisa.findByDataFim", query = "SELECT p FROM Pesquisa p WHERE p.dataFim = :dataFim"), @NamedQuery(name = "Pesquisa.findByHoraFim", query = "SELECT p FROM Pesquisa p WHERE p.horaFim = :horaFim"), @NamedQuery(name = "Pesquisa.findByUrlBanner", query = "SELECT p FROM Pesquisa p WHERE p.urlBanner = :urlBanner"), @NamedQuery(name = "Pesquisa.findByUsuario", query = "SELECT p FROM Pesquisa p WHERE p.usuario = :usuario"), @NamedQuery(name = "Pesquisa.findByEndereco", query = "SELECT p FROM Pesquisa p WHERE p.endereco = :endereco"), @NamedQuery(name = "Pesquisa.findByBairro", query = "SELECT p FROM Pesquisa p WHERE p.bairro = :bairro"), @NamedQuery(name = "Pesquisa.findByCidade", query = "SELECT p FROM Pesquisa p WHERE p.cidade = :cidade"), @NamedQuery(name = "Pesquisa.findByCep", query = "SELECT p FROM Pesquisa p WHERE p.cep = :cep"), @NamedQuery(name = "Pesquisa.findByEstado", query = "SELECT p FROM Pesquisa p WHERE p.estado = :estado"), @NamedQuery(name = "Pesquisa.findByTelefone", query = "SELECT p FROM Pesquisa p WHERE p.telefone = :telefone"), @NamedQuery(name = "Pesquisa.findByPublicar", query = "SELECT p FROM Pesquisa p WHERE p.publicar = :publicar"), @NamedQuery(name = "Pesquisa.findByEmail", query = "SELECT p FROM Pesquisa p WHERE p.email = :email"), @NamedQuery(name = "Pesquisa.findBySugestao", query = "SELECT p FROM Pesquisa p WHERE p.sugestao = :sugestao"), @NamedQuery(name = "Pesquisa.findByUrlLink", query = "SELECT p FROM Pesquisa p WHERE p.urlLink = :urlLink"), @NamedQuery(name = "Pesquisa.findByExigeLogin", query = "SELECT p FROM Pesquisa p WHERE p.exigeLogin = :exigeLogin"), @NamedQuery(name = "Pesquisa.findByIdentificacao", query = "SELECT p FROM Pesquisa p WHERE p.identificacao = :identificacao"), @NamedQuery(name = "Pesquisa.findByLoginAnonimo", query = "SELECT p FROM Pesquisa p WHERE p.loginAnonimo = :loginAnonimo")})
public class Pesquisa implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @Column(name = "id", nullable = false)
    private Integer id;
    @Column(name = "nome")
    private String nome;
    @Column(name = "descricao")
    private String descricao;
    @Column(name = "data_inicio")
    @Temporal(TemporalType.DATE)
    private Date dataInicio;
    @Column(name = "hora_inicio")
    @Temporal(TemporalType.TIME)
    private Date horaInicio;
    @Column(name = "data_fim")
    @Temporal(TemporalType.DATE)
    private Date dataFim;
    @Column(name = "hora_fim")
    @Temporal(TemporalType.TIME)
    private Date horaFim;
    @Column(name = "url_banner")
    private String urlBanner;
    @Column(name = "usuario")
    private Character usuario;
    @Column(name = "endereco")
    private Character endereco;
    @Column(name = "bairro")
    private Character bairro;
    @Column(name = "cidade")
    private Character cidade;
    @Column(name = "cep")
    private Character cep;
    @Column(name = "estado")
    private Character estado;
    @Column(name = "telefone")
    private Character telefone;
    @Column(name = "publicar")
    private Character publicar;
    @Column(name = "email")
    private Character email;
    @Column(name = "sugestao")
    private Character sugestao;
    @Column(name = "url_link")
    private String urlLink;
    @Column(name = "exige_login")
    private Character exigeLogin;
    @Column(name = "identificacao")
    private Character identificacao;
    @Column(name = "login_anonimo")
    private Character loginAnonimo;
    @JoinTable(name = "Pesquisa_grupo", joinColumns = {@JoinColumn(name = "Pesquisa_id", referencedColumnName = "id")}, inverseJoinColumns = {@JoinColumn(name = "grupo_perguntas_id", referencedColumnName = "id")})
    @ManyToMany
    private Collection<GrupoPerguntas> grupoPerguntasIdCollection;   
    @ManyToMany
    private Collection<Usuario> usuarioidCollection;
    @JoinColumn(name = "responsavel", referencedColumnName = "id")
    @ManyToOne
    private Usuario responsavel;
  
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "pesquisa")
    private Collection<Pesquisagrupoperg> pesquisagrupopergCollection;

    public Pesquisa() {
    }

    public Pesquisa(Integer id) {
        this.id = id;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getNome() {
        return nome;
    }

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

    public String getDescricao() {
        return descricao;
    }

    public void setDescricao(String descricao) {
        this.descricao = descricao;
    }

    public Date getDataInicio() {
        return dataInicio;
    }

    public void setDataInicio(Date dataInicio) {
        this.dataInicio = dataInicio;
    }

    public Date getHoraInicio() {
        return horaInicio;
    }

    public void setHoraInicio(Date horaInicio) {
        this.horaInicio = horaInicio;
    }

    public Date getDataFim() {
        return dataFim;
    }

    public void setDataFim(Date dataFim) {
        this.dataFim = dataFim;
    }

    public Date getHoraFim() {
        return horaFim;
    }

    public void setHoraFim(Date horaFim) {
        this.horaFim = horaFim;
    }

    public String getUrlBanner() {
        return urlBanner;
    }

    public void setUrlBanner(String urlBanner) {
        this.urlBanner = urlBanner;
    }

    public Character getUsuario() {
        return usuario;
    }

    public void setUsuario(Character usuario) {
        this.usuario = usuario;
    }

    public Character getEndereco() {
        return endereco;
    }

    public void setEndereco(Character endereco) {
        this.endereco = endereco;
    }

    public Character getBairro() {
        return bairro;
    }

    public void setBairro(Character bairro) {
        this.bairro = bairro;
    }

    public Character getCidade() {
        return cidade;
    }

    public void setCidade(Character cidade) {
        this.cidade = cidade;
    }

    public Character getCep() {
        return cep;
    }

    public void setCep(Character cep) {
        this.cep = cep;
    }

    public Character getEstado() {
        return estado;
    }

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

    public Character getTelefone() {
        return telefone;
    }

    public void setTelefone(Character telefone) {
        this.telefone = telefone;
    }

    public Character getPublicar() {
        return publicar;
    }

    public void setPublicar(Character publicar) {
        this.publicar = publicar;
    }

    public Character getEmail() {
        return email;
    }

    public void setEmail(Character email) {
        this.email = email;
    }

    public Character getSugestao() {
        return sugestao;
    }

    public void setSugestao(Character sugestao) {
        this.sugestao = sugestao;
    }

    public String getUrlLink() {
        return urlLink;
    }

    public void setUrlLink(String urlLink) {
        this.urlLink = urlLink;
    }

    public Character getExigeLogin() {
        return exigeLogin;
    }

    public void setExigeLogin(Character exigeLogin) {
        this.exigeLogin = exigeLogin;
    }

    public Character getIdentificacao() {
        return identificacao;
    }

    public void setIdentificacao(Character identificacao) {
        this.identificacao = identificacao;
    }

    public Character getLoginAnonimo() {
        return loginAnonimo;
    }

    public void setLoginAnonimo(Character loginAnonimo) {
        this.loginAnonimo = loginAnonimo;
    }

    public Collection<GrupoPerguntas> getGrupoPerguntasIdCollection() {
        return grupoPerguntasIdCollection;
    }

    public void setGrupoPerguntasIdCollection(Collection<GrupoPerguntas> grupoPerguntasIdCollection) {
        this.grupoPerguntasIdCollection = grupoPerguntasIdCollection;
    }

    public Collection<Usuario> getUsuarioidCollection() {
        return usuarioidCollection;
    }

    public void setUsuarioidCollection(Collection<Usuario> usuarioidCollection) {
        this.usuarioidCollection = usuarioidCollection;
    }

    public Usuario getResponsavel() {
        return responsavel;
    }

    public void setResponsavel(Usuario responsavel) {
        this.responsavel = responsavel;
    }

   
    public Collection<Pesquisagrupoperg> getPesquisagrupopergCollection() {
        return pesquisagrupopergCollection;
    }

    public void setPesquisagrupopergCollection(Collection<Pesquisagrupoperg> pesquisagrupopergCollection) {
        this.pesquisagrupopergCollection = pesquisagrupopergCollection;
    }

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

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

    @Override
    public String toString() {
        return "entidades.Pesquisa[id=" + id + "]";
    }

}