TreeTable is a combination of Tree and Table. It can be very nice component when you want to display tabular data in a hierarchical manner. Last week when I was looking for a component that can be used to implement TreeTable, I came across JXTreeTable. It is a component of SwingX package by SwingLabs.
Using JXTreeTable we can create TreeTable very easily. Only difficult part is creating the DataModel to match with our requirement.