The interviewer was interested in how much I remember about the behavior of the APIs rather than my problem-solving skills.
Then he asked me standard Core Java questions while I had no experience in Java other than in Android and I had never worked in those Core Java topics. I answered all except one using my intuition and problem-solving skills and later found out that my answers were right. He did not like it that I did not know the answer right away so he asked me if I had any experience in threads which I did not have. He looked very disappointed as if this is not the type of candidate he asked for.