The new 1Z0-819 certification is the combination of the old existing ones (1Z0-815 & 1Z0-816) together.
OCP Java SE 11 Programmer I - Study guide for 1Z0-815
1. Welcome to Java
2. Java Building Blocks
3. Java Operators
4. Making Decisions
5. Core Java APIs
6. Lambdas and Functional Interfaces
7. Methods and Encapsulation
8. Class Design
9. Advanced Class Design
10. Exceptions
11. Java Modules
OCP Java SE 11 Programmer II - Study guide for 1Z0-816
1. Java Fundamentals
2. Java Annotations
3. Generics and Collections
(to continue)