Adam Lee Brown, 49, of Portland, was charged with attempted murder, kidnapping and assault following the bloody July 1 attack.
Brown grabbed the 10-year-old boy inside the restaurant, and pulled him into a bathroom.
The boy's father tried to open the door but had to get the manager to unlock it. At that point, Brown opened the door, shoved the injured boy outside and then locked himself inside the restroom. Several people who were in the restaurant held the door shut until police arrived.
Brown barricaded himself in the bathroom for several hours before eventually surrenduring to police.
In court on Wednesday, the boy's parents had the prosecutor read a statement to Brown, saying "you are a sick evil twisted human being. The horror our son feels will always be in the depths of his mind, but broken is something he'll never be."
Brown was declared a "predatory" sex offender after he was convicted for sodomy in December of 1993.
According to news reports from KATU and others in 1993, Brown had unprotected sex with children and tried to infect them with HIV, the virus that causes AIDS.
Prosecutors said he victimized nine kids, five of whom were exposed to HIV. He targeted both male and female children between two and eight years old.
Brown sexually assaulted children who were in the care of acquaintances, and gave them drugs and alcohol, according to the sex offender registry.
He was not allowed to have contact with minors after his release or frequent places where minors regularly congregate.
He was paroled in 2004, but his original sentence was 16 years, which means he would have gotten out of jail in 2009 whether his parole was denied or allowed.
At the time of the latest attack, Brown also had an outstanding warrant for a parole violation.