@EnableCaching annotation in Spring Boot - Step-by-Step Execution

Concept Flow - @EnableCaching annotation

Start Application

↓

Spring Boot scans for @EnableCaching

↓

Enable Cache Infrastructure

↓

Detect @Cacheable, @CachePut, @CacheEvict

↓

Wrap methods with caching logic

↓

On method call: Check cache

↓

Return cached

↓

Store result in cache

↓

Return result

↓

End

This flow shows how Spring Boot detects @EnableCaching, sets up caching, and intercepts method calls to use or update the cache.

Execution Sample

Spring Boot

@SpringBootApplication
@EnableCaching
public class App {
  @Cacheable("books")
  public Book getBook(String id) {
    // fetch book from DB
  }
}

This code enables caching and caches results of getBook method by book id.

Execution Table

Step	Action	Cache State	Method Call	Cache Hit?	Result Returned
1	Application starts, @EnableCaching detected	Empty	No	N/A	N/A
2	Call getBook("123")	Empty	Yes	No	Fetch from DB
3	Store result in cache key "123"	Contains key "123"	No	N/A	N/A
4	Call getBook("123") again	Contains key "123"	Yes	Yes	Return cached book
5	Call getBook("456")	Contains keys "123"	Yes	No	Fetch from DB
6	Store result in cache key "456"	Contains keys "123", "456"	No	N/A	N/A
7	Call getBook("123") again	Contains keys "123", "456"	Yes	Yes	Return cached book

💡 Execution stops when no more method calls occur.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 5	After Step 6	Final
cache	{}	{"123": Book123}	{"123": Book123}	{"123": Book123}	{"123": Book123, "456": Book456}	{"123": Book123, "456": Book456}

Key Moments - 2 Insights

Why does the method execute the first time but not the second time for the same argument?

At step 2, the cache is empty so the method runs and result is stored (step 3). At step 4, the cache has the key so the cached result is returned without running the method.

What happens if a new argument is passed to the cached method?

At step 5, the argument "456" is not in cache, so the method runs and stores the result (step 6). This shows caching is per argument.

Visual Quiz - 3 Questions

Look at the execution table, what is the cache state after step 3?

A Contains key "123"

B Empty

C Contains keys "123" and "456"

D Contains key "456" only

💡 Hint

Check the 'Cache State' column at step 3 in the execution table.

At which step does the method getBook("123") return a cached result?

A Step 2

B Step 4

C Step 5

D Step 6

💡 Hint

Look for 'Cache Hit?' column for getBook("123") calls in the execution table.

If @EnableCaching was removed, how would the cache state change after step 3?

A Cache would still contain key "123"

B Cache would remain empty

C Cache would contain keys "123" and "456"

D Cache would contain key "456" only

💡 Hint

Without @EnableCaching, caching is not activated, so cache stays empty.

Concept Snapshot

@EnableCaching enables Spring's caching support.
Add @EnableCaching on a config class to activate caching.
Use @Cacheable on methods to cache results by arguments.
On method call, cache is checked first.
If cached, return cached result; else run method and cache result.
Caching improves performance by avoiding repeated work.

Full Transcript

The @EnableCaching annotation tells Spring Boot to turn on caching features. When the app starts, Spring scans for this annotation and sets up caching behind the scenes. Methods marked with @Cacheable will have their results saved in a cache after the first call. Later calls with the same arguments return the cached result instead of running the method again. This saves time and resources. The execution table shows how the cache starts empty, fills with results after method calls, and returns cached data on repeated calls. Without @EnableCaching, caching does not happen and the cache stays empty. This simple setup helps apps run faster by reusing previous results.