Please suggests me some project ideas using java

Answer 1

Depending on your level, this takes you through a growth process.

https://www.sololearn.com/post/1629747/?ref=app

Answer 2

https://hackr.io/blog/java-projects

I hope it's helpful to you

Answer 3

Would advice to develop a web crawler, you get to know how multithreading works and also plain Java at same time