In today’s world, where speed and performance are critical for a successful API, caching plays a vital role in improving response times and reducing the load on backend services. With Java Spring REST Docs, you can document and communicate your API’s caching strategies and performance considerations effectively.

Caching with Spring Cache

Spring Cache is a powerful caching abstraction provided by the Spring Framework. It allows you to easily integrate caching into your application without any vendor lock-in. Let’s take a look at how we can leverage Spring Cache to implement caching in our API.

First, we need to enable caching in our Spring application. To do this, annotate your configuration class with @EnableCaching. Then, annotate the methods in your service or repository classes that you want to cache with @Cacheable or @CachePut annotations.

For example, consider a method that fetches user details from a database:

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;
    
    @Cacheable("users")
    public User getUserById(Long userId) {
        return userRepository.findById(userId);
    }
}

In the example above, we have annotated the getUserById method with @Cacheable("users"). This tells Spring to cache the result of the method using the cache name “users”. The next time the method is called with the same input, the result will be retrieved from the cache instead of the database.

To document this caching behavior in your API documentation, you can use Java Spring REST Docs. By writing tests for your API endpoints, you can generate documentation that showcases caching behavior.

Documenting API Caching using Java Spring REST Docs

Java Spring REST Docs allows you to document your API using tests written in Java. These tests not only verify the functionality of your API but also serve as a living documentation for your API users.

To document the caching behavior of your API, you can write a test case that invokes the endpoint multiple times and verifies the caching behavior.

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserApiDocumentation {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void getUserById_shouldCacheResponse() throws Exception {
        mockMvc.perform(get("/users/{id}", 1))
                .andExpect(status().isOk())
                .andDo(document("getUserById"))
                .andReturn().getResponse();
        
        mockMvc.perform(get("/users/{id}", 1))
                .andExpect(status().isOk())
                .andDo(document("getUserById"))
                .andReturn().getResponse();
    }
}

In the above example, we have written a test case that invokes the /users/{id} endpoint twice. By calling andDo(document("getUserById")), we instruct Spring REST Docs to document this API endpoint, including its caching behavior.

By running this test case, you can generate API documentation that clearly communicates the caching behavior of the “getUserById” endpoint.

Conclusion

In this blog post, we discussed how to leverage caching using Java Spring REST Docs. We explored how to integrate caching with Spring Cache and document the caching behavior in our API documentation using Spring REST Docs. By documenting our caching strategies and performance considerations, we can help API users understand and utilize our API effectively. So, start documenting your API caching and performance considerations today to provide a seamless experience to your users!

#API #Caching #Java #Spring #RESTDocs