Improvement skills in java

Question

, I am a Java programmer.I need to improve my programming skills. Do you know any website which have open source project or programming assignments of advance level (not like Factorial even and odd numbers programs). SO I can understand the existing code and then change the code as per my requirement. Please share if you know any such websites.
#Need_Help
#Thanks in advance

Answer 1

https://www.sololearn.com/Discuss/437973/?ref=app

Answer 2

What projects have you made?

Answer 3

check out the Android development site

Answer 4

Be practicing.....