Record a JVM GC process

JVM The heap is divided into the new generation and the old generation , About the proportion 1：2, The new generation is divided into 1 individual eden Area and 2 individual survivor District , The approximate ratio is 8：1：1

GC The process ：

1. Big target directly into the old age
2. Small objects first eden Partition memory , When eden When it's full , Trigger once Minor GC, clear eden Area
3. The surviving object enters survivor Area , Age +1
4. When age >15( Default ) When we entered the old age , Trigger once when the old generation is full Full GC