How do I open .dat file using IntelliJ Idea??

Hello, I got an assignment to build a b+ tree.

I decided to use Java, and I'm using IntelliJ Idea 2019.2.1.

I have to store index and data to a .dat format file.

I would like to check whether the data are stored in the .dat file without reading the file again...

Is there a way where I could see the data in .dat file through IntelliJ database tool??