  We compute the effect of a d-wave magnetization (altermagnetism) on the
spectrum of bound states (Andreev levels) in a junction between two s-wave
superconductors (gap $\Delta_0$, phase difference $\phi$). Compared to a
nonmagnetic junction, the $\phi$-dependence of the spectrum is shifted by an
offset $\pm\delta\phi$, dependent on the spin direction, so that the Andreev
levels become spin-polarized. In a planar junction, oriented along the
crystalline axis of $d_{xy}$-wave symmetry, the excitation energies are
determined by the normal-state transmission probability $T$ according to
$E=\Delta_0\sqrt{1-T\sin^2\tfrac{1}{2}(\phi\pm\delta\phi)}$. We calculate the
corresponding Josephson energy and supercurrent, recovering the 0-$\pi$
transition of related studies.
