What is the Java library (server) for handling a large number of UDP datagrams?

Question

Java

The question is - what kind of Java library (server) exists, and does it exist, designed to receive and process a large number of UDP datagrams?
So the requirements are:

1. Open source, liberal license
   
2. pure java
   
3. Good performance, must withstand loads
   
4. Protocol - UDP
   

Thank you!

Answer 1

Look towards netty.
netty.io