[FIXED] Is it good practice to use a `@Configuration` bean as a normal bean?

Issue

In spring, we can mark a class as @Configuration, and use it to configure the beans.

But the bean can also be used as a normal bean, see the example:

@Configuration
@EnableCaching
public class CacheConfig {
    private List<GuavaCache> caches = Collections.emptyList();

    @Bean
    public CacheManager cacheManager() {
        SimpleCacheManager cacheManager = new SimpleCacheManager();
        cacheManager.setCaches(caches);

        return cacheManager;
    }

    public String statistics() {
        StringBuilder sb = new StringBuilder();
        for (GuavaCache cache : caches) {
            sb.append(cache.statistics()).append("\n");
        }
        return sb.toString();
    }

}

You can see we configured a CacheManager bean in this CacheConfig, but it also contains a normal statistics method that we can reference this bean and invoke it.

I just wonder is it the recommended way to use @Configuration class?

Personally, I would avoid it, because it mixes two responsabilities, "creating beans", "providing some business logic". I prefer creating another bean for the statistics (the code following maybe incorrect, just for demo).

@Configuration
@EnableCaching
public class CacheConfig {
    private List<GuavaCache> caches = Collections.emptyList();

    @Bean
    public CacheManager cacheManager() {
        SimpleCacheManager cacheManager = new SimpleCacheManager();
        cacheManager.setCaches(caches);
        return cacheManager;
    }

    @Bean
    public CacheStatistics cacheStatistics() {
        return new CacheStatistics(caches);
    }

}

class CacheStatistics {
    private List<GuavaCache> caches;
    public CacheStatistics(List<GuavaCache> caches) {
        this.caches = caches;
    }
    public String statistics() {
        StringBuilder sb = new StringBuilder();
        for (GuavaCache cache : caches) {
            sb.append(cache.statistics()).append("\n");
        }
        return sb.toString();
    }
}

Solution

Basically we used @Configuration to replace .xml files in spring.This files are not used for putting up business logic

So we need to take care if we using @Configuration we just use it for declaring beans.I don't think we put other things there well.

Thanks, Himanshu

Answered By - himanshu bisht
Answer Checked By - Robin (JavaFixing Admin)