  In this paper, by setting proper boundaries in the Minkowski spacetime, we
construct three toy model spacetimes, a toy black hole, a toy white hole, and a
toy wormhole. Based on these model spacetimes, we discuss the Hawking radiation
and the information loss problem. By counting the number of the field modes
inside and outside the horizon, we show the thermal radiation of the toy black
hole. We show that the white hole have a thermal absorption. We show that in
the whole toy wormhole spacetime, there is no information lost. In addition, we
show the black hole radiation and the white hole absorption are independent of
the choices of boundary conditions at the singularity. We also show the
physical effects caused by two particular boundary conditions.
