How to implement an in-memory cache in Spring Boot with Java 8 that stores a list of strings and loads automatically on application startup?

Question

I am trying to implement an in-memory cache in a Spring Boot application using Java 8. The cache should store a list of String values, and it should automatically load with values at application startup.

Here are the key requirements:

1. In-memory storage: The cache should reside in memory.
2. Stores list of strings: The cache will store a collection of String values.
3. Automatic loading at startup: The cache should be populated with initial data when the application starts (e.g., loading data from a file or database).
4. Java 8-specific approaches: I'm curious if there are any features or approaches in Java 8 that could make this implementation more efficient or cleaner.

I have considered using Spring's @Cacheable annotation, but I am not sure if that's the best approach, given that I want the cache to load automatically during startup.

Could you suggest an approach to implement this cache efficiently using Spring Boot and Java 8?

What I’m looking for:

• Efficient in-memory cache with automatic loading.
• Java 8-specific tools or optimizations (if available).
• A code example of how the cache can be implemented, initialized at startup, and accessed during runtime.