@Cacheable for read caching in Spring Boot - Mini Project: Build & Apply

Using @Cacheable for Read Caching in Spring Boot

📖 Scenario: You are building a simple Spring Boot application that fetches user details from a database. To improve performance, you want to cache the user data when it is read, so repeated requests for the same user do not hit the database every time.

🎯 Goal: Learn how to use the @Cacheable annotation in Spring Boot to cache method results for faster read access.

📋 What You'll Learn

Create a service class with a method to get user details by ID

Add a cache configuration variable

Use @Cacheable annotation on the method to enable caching

Complete the Spring Boot application setup to support caching

💡 Why This Matters

🌍 Real World

Caching read data like user details reduces database load and speeds up response times in web applications.

💼 Career

Understanding and implementing caching with Spring Boot is a common requirement for backend developers to optimize application performance.

1

Create UserService with getUserById method

Create a class called UserService with a method getUserById that takes a Long id parameter and returns a String representing user details. Inside the method, return the string "User details for id: " + id.

Spring Boot

public class UserService {
    // Your code here
}

Need a hint?

Define a public class named UserService. Inside it, create a public method getUserById that returns a string combining the fixed text and the id parameter.

2

Add cache name configuration

Inside the UserService class, add a public static final String variable called CACHE_NAME and set it to "users".

Spring Boot

public class UserService {
    public static final String CACHE_NAME = "users";
    // Your code here

    public String getUserById(Long id) {
        return "User details for id: " + id;
    }
}

Need a hint?

Define a constant string CACHE_NAME inside the class to hold the cache name "users".

3

Add @Cacheable annotation to getUserById method

Import org.springframework.cache.annotation.Cacheable and annotate the getUserById method with @Cacheable(cacheNames = UserService.CACHE_NAME) to enable caching of the method's return value.

Spring Boot

import org.springframework.cache.annotation.Cacheable;

public class UserService {
    public static final String CACHE_NAME = "users";

    @Cacheable(cacheNames = UserService.CACHE_NAME)
    // Your code here
    public String getUserById(Long id) {
        return "User details for id: " + id;
    }
}

Need a hint?

Use the @Cacheable annotation above the method and specify the cache name using the constant UserService.CACHE_NAME.

4

Enable caching in Spring Boot application

In your main Spring Boot application class, import org.springframework.cache.annotation.EnableCaching and add the @EnableCaching annotation above the class declaration to activate caching support.

Spring Boot

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
// Add import for EnableCaching

// Add @EnableCaching annotation
@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

Need a hint?

Import @EnableCaching and place it above the main application class to enable caching features in Spring Boot.