ProfilingBeanPostProcessor.java

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;

import java.time.Duration;
import java.time.Instant;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

@Component
public class ProfilingBeanPostProcessor implements BeanPostProcessor {

    private static final Logger log = LoggerFactory.getLogger(ProfilingBeanPostProcessor.class);

    private final Map<String, Instant> beansCreationTime = new ConcurrentHashMap<>();

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        beansCreationTime.put(beanName, Instant.now());
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        final Instant endTime = Instant.now();
        final Instant startTime = beansCreationTime.get(beanName);
        final long initializationTimeMillis = Duration.between(startTime, endTime).toMillis();
        log.warn("Bean {} created in {}ms", beanName, initializationTimeMillis);
        return bean;
    }
}