빈 후처리기 적용

빈 후처리기

@Slf4j
public class PackageLogTracePostProcessor implements BeanPostProcessor {
    private final String basePackges;
    private final Advisor advisor;

    public PackageLogTracePostProcessor(String basePackges, Advisor advisor) {
        this.basePackges = basePackges;
        this.advisor = advisor;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        log.info("beanName={}, bean={}", beanName, bean.getClass());

        String packageName = bean.getClass().getPackageName();
        if (packageName.startsWith(basePackges)) {
            return bean;
        }

        ProxyFactory proxyFactory = new ProxyFactory(bean);
        proxyFactory.addAdvisor(advisor);

        Object proxy = proxyFactory.getProxy();
        log.info("create proxy: target={}, proxy={}", bean.getClass(), proxy.getClass());
        return proxy;
    }
}

설정

@Slf4j
@Configuration
@Import({AppV1Config.class, AppV2Config.class})
public class BeanPostProcessorConfig {

    @Bean
    public PackageLogTracePostProcessor logTracePostProcessor(LogTrace logTrace) {
        return new PackageLogTracePostProcessor("hello.proxy.app", getAdvisor(logTrace));
    }

    private Advisor getAdvisor(LogTrace logTrace) {
        //pointcut
        NameMatchMethodPointcut pointcut = new NameMatchMethodPointcut();
        pointcut.setMappedNames("request*", "order*", "save*");
        //advice
        LogTraceAdvice advice = new LogTraceAdvice(logTrace);
        //advisor = pointcut + advice
        return new DefaultPointcutAdvisor(pointcut, advice);
    }
}

메인

@Import(BeanPostProcessorConfig.class)
@SpringBootApplication(scanBasePackages = "hello.proxy.app.v3")
public class ProxyApplication {

	public static void main(String[] args) {
		SpringApplication.run(ProxyApplication.class, args);
	}

	@Bean
	public LogTrace logTrace() {
		return new ThreadLocalLogTrace();
	}

}

정리

• 수동으로 등록하는 빈은 물론이고, 컴포넌트 스캔을 사용하는 빈까지 모두 프록시를 적용할 수 있다
• 설정 파일에 있는 수 많은 프록시 생성 코드도 한번에 제거할 수 있다.