Johnson has no hits or runs through seven innings, walking three and striking out nine. No Brave has yet to reach second base. And it's not like he's tailing off due to fatigue; Johnson struck out Jason Heyward and Dan Uggla to end the seventh.
The one issue for Johnson is pitch count. He is at 105 through seven innings, throwing 68 for strikes. Johnson is a big guy who constantly hits the 100+ mark in his starts, so it shouldn't be an issue for the eighth inning, but if the no-hitter continues into the ninth, he could be looking at a 120+ mark.
Johnson will face Alex Gonzalez, Freddie Freeman and the pitcher's spot in the eighth, which favors him considerably. The ninth could be the true test if he reaches it.