Caching is a common performance optimization technique for web applications. It can speed up responses by storing frequently accessed data in memory so that it can be quickly retrieved the next time it is needed.
Spring Boot provides several built-in caching solutions, including the SimpleKeyGenerator, which can be used to generate cache keys based on the parameters of a method. There are also a number of third-party cache libraries that can be used with Spring Boot, such as Ehcache, Hazelcast, and Redis.
In this article, we will take a look at how to configure caching with Spring Boot and explore some of the more common use cases for caching data.
Spring Boot provides several different ways to configure caching. The simplest way is to add the @EnableCaching annotation to a Spring Boot application:
@SpringBootApplication
@EnableCaching
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
This will enable caching for all methods annotated with @Cacheable in the application.
It is also possible to specify the cache manager to be used by Spring Boot. For example, to use the Ehcache cache manager, the following property can be added to the application.properties file:
spring.cache.type=ehcache
Now that we have caching enabled in our Spring Boot application, let's look at some examples of how we can cache data.
One common use case for caching is to cache the results of method calls. This can be done by annotating the method with @Cacheable and specifying the name of the cache to use:
@Cacheable("books")
public List<Book> getBooks() {
// ...
}
In this example, the results of the getBooks() method will be cached in a cache named "books".
It is also possible to specify the key to use for caching the results of the method. For example, to cache the results of the getBooks() method using the id of the book as the key, the following annotation can be used:
@Cacheable(value="books", key="#id")
public List<Book> getBooks(Long id) {
// ...
}
Another common use case for caching is to cache method parameters. This can be done by annotating the method with @CachePut and specifying the name of the cache to use:
@CachePut("books")
public void updateBook(Book book) {
// ...
}
In this example, the updateBook() method will cache the book object in the "books" cache.
It is also possible to specify the key to use for caching the method parameters. For example, to cache the book object using the id of the book as the key, the following annotation can be used:
@CachePut(value="books", key="#book.id")
public void updateBook(Book book) {
// ...
}
Another common use case for caching is to cache the results of method calls. This can be done by annotating the method with @Cacheable and specifying the name of the cache to use:
@Cacheable("books")
public List<Book> getBooks() {
// ...
}
In this example, the results of the getBooks() method will be cached in a cache named "books".
It is also possible to specify the key to use for caching the results of the method. For example, to cache the results of the getBooks() method using the id of the book as the key, the following annotation can be used:
@Cacheable(value="books", key="#id")
public List<Book> getBooks(Long id) {
// ...
}
In this article, we have looked at how to configure caching with Spring Boot and explored some of the more common use cases for caching data. Caching can be a useful performance optimization technique for web applications. It can speed up responses by storing frequently accessed data in memory so that it can be quickly retrieved the next time it is needed.