  We present a holographic analysis of diffractive photoproducton of charmonium
$J/\psi$ and upsilonium $\Upsilon$ on a proton, considered as a bulk Dirac
fermion, for all ranges of $\sqrt{s}$, i.e., from near threshold to very high
energy. Using the bulk wave functions of the proton and vector mesons, within
holographic QCD, and employing Witten diagrams in the bulk, we compute the
diffractive photoproduction amplitude of $J/\psi$ and $\Upsilon$. The
holographic amplitude shows elements of the strictures of vector meson
dominance (VMD). It is dominated by the exchange of a massive graviton or
$2^{++}$ glueball resonances near threshold, and its higher spin-j counterparts
that reggeize at higher energies. Both the differential and total cross
sections are controlled by the gravitational form factor $A(t)$, and compare
well to the recent results reported by the GlueX collaboration near threshold
and the world data at large $\sqrt{s}$. The holographic gravitational form
factors, including the D-term, which is due to the exchange of massive spin-0
glueballs, are in good agreement with lattice simulations. We use it to extract
the holographic pressure and shear forces inside the proton. Finally, using a
pertinent integral representation of the holographic gravitational form factor
$A(t)$ near threshold, and its Pomeron counterpart way above threshold, we
extract the generalized parton distribution (GPD) of gluons inside the proton
at different resolutions.
