I wanna share my experience on 1Z0-8080. The preparation took about 2 months. I was too lazy for reading books, so I order Oracle Java Certification - Pass the Associate 1Z0-8080 from Udemy, really good course, I wanna recommend to all of you. What about mock tests? First, I order Java Certification: OCA Associate 1Z0-8080 exam Simulation from Udemy as well, my average 80%, but these test are too easy in my opinion, and not enough for preparation. Second choice was whizlabs.com (average around 80%), but I was kind a disappointed of this service, really bad font, hard to read questions, tests contains several errors, also was questions about enums (out of scope). So at the last I go for https://enthuware.com/
(average 78%) page for ordering tests, web-page looks like a scamp/fraud (really very poor design, I though they wanna steal my money). Enthuware mock tests in my opinion really really good compared to other services, questions are very well balanced, so many thanks goes to enthuware. Today I took exam, first 7 questions were really tricky for me, it took for me around 30 minutes, I was in shock, disappointed wanna leave test room, but later goes everything well. I would give you one advice, if it seems to hard for you solve question, mark as "review", don't spend so much time, go for another question(It was my mistake). Final word, good luck to everyone in exams!