Then Johnson allegedly forced her into his bedroom and made her sit in a chair for hours. Shortly before 4 a.m., she asked Johnson if she could leave, and he finally agreed, police said.
The alleged assault happened at the Edge, a building where Temple rents several floors because the demand for student housing outweighs the supply.
The woman reported the incident to police on Thursday and told officers that Johnson had been abusive during their three-year relationship.
Police said that she suffered scratches, bruising and a contusion on her head, and that it made her dizzy and blurred her vision.
"My head was hurting so bad, and then when I wiped my neck, I realized I was bleeding," she told NBC 10, describing what she said happened that night. "I asked him if I could go to the bathroom. He told me, 'No. You're going to sit right there.' "
She told NBC 10 that she did not seek medical treatment.
Johnson, of Willingboro, N.J., turned himself in at the Central Detective Division on Friday. He was charged with kidnapping, unlawful restraint, simple assault, recklessly endangering another person and related offenses. Bail was set at $25,000.
Johnson had started in Temple's first two games this season against Villanova and Maryland. Temple coach Steve Addazio had no comment on Johnson's arrest or his status with the team after Saturday's 37-28 win against South Florida.
Temple University spokesman Ray Betzner said that the university was not making any statement about the matter.
Johnson could not be reached for comment.
Contact Barbara Laker at 215-854-5933 or lakerb@ phillynews.com, or follow on Twitter @barbaralaker.