Text filter by state and information of an alumn JAVA

This is my code for that function:

public List<Alumno> filtro(String filtrar,char estado) throws DAOException 
{


List<Alumno> listaAlu = new ArrayList<>(); //The list that i return.

This is my sql statement  that is contained in an String named sentencia:

                "select*\n"+    "fromalumnos\n"+ 
                "where dni like '%"+filtrar+"%'"+
                "or apyn like '%"+filtrar+"%'"+ 
                "or sexo like '%"+filtrar+"%'" +
                "or fec_nac like '%"+filtrar+"%'"+ 
                "or cant_mat_aprob like '%"+filtrar+"%'"+ 
                "or promedio like '%"+filtrar+"%'"+ 
                "or fec_ing like '%"+filtrar+"%'"+ 
                "or carrera like '%"+filtrar+"%'" + 
                "and estado = '"+estado+"'";

        Statement statement;
        ResultSet rs;

        try {
            statement = conection.createStatement();
            rs = statement.executeQuery(sentencia);
            while(rs.next()) {
                listaAlu = AñadirLista(rs, listaAlu);
            }       
            return listaAlu;
        } catch (SQLException | DAOException ex) {
            Logger.getLogger(AlumnoDAOJDBC.class.getName()).log(Level.SEVERE, null, ex);
            throw new DAOException("Buscar falló: " + ex.getMessage());
        }    
}

this is AñadirLista function:

    Alumno alu = new Alumno();
    getAluDeResultSet(rs, alu);
    listaAlu.add(alu);
    return listaAlu;

i don't know what to do to filter it by their state, i send it as a parameter named "estado" and the information of the object is "filtrar". Thanks