SpringSpring 고급편Dynamic Proxy

Spring 핵심원리 고급편 - Dynamic Proxy 2

목차

public class LogTraceBasicHandler implements InvocationHandler {

    private final Object target;
    private final LogTrace logTrace;

    public LogTraceBasicHandler(Object target, LogTrace logTrace) {
        this.target = target;
        this.logTrace = logTrace;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        TraceStatus status = null;

        try {
            String message = method.getDeclaringClass().getSimpleName() + "." + method.getName() + "()";
            status = logTrace.begin(message);

            // 로직 호출
            method.invoke(target, args);
            logTrace.end(status);

            return result;
        } catch (Exception ex) {
            logTrace.exception(status, ex);
            throw ex;
        }
    }
}

@Configuration
public class DynamicBasicProxyConfig {

    @Bean
    public OrderControllerV1 orderControllerV1(LogTrace logTrace){
        OrderControllerV1 orderControllerV1 = new OrderControllerV1Impl(orderServiceV1(logTrace));

        // Proxy 객체 생성
        OrderControllerV1 proxy = (OrderControllerV1) Proxy
                .newProxyInstance(
                    OrderControllerV1.class.getClassLoader(),
                    new Class[]{OrderControllerV1.class},
                    new LogTraceBasicHandler(orderControllerV1, logTrace));

        return proxy;
    }

    @Bean
    public OrderServiceV1 orderServiceV1(LogTrace logTrace){
        OrderServiceV1 orderServiceV1 = new OrderServiceV1Impl(orderRepositoryV1(logTrace));

        // Proxy 객체 생성
        OrderServiceV1 proxy = (OrderServiceV1) Proxy
                .newProxyInstance(
                    OrderServiceV1.class.getClassLoader(),
                    new Class[]{OrderServiceV1.class},
                    new LogTraceBasicHandler(orderServiceV1, logTrace));

        return proxy;
    }

    @Bean
    public OrderRepositoryV1 orderRepositoryV1(LogTrace logTrace){
        OrderRepositoryV1 orderRepository = new OrderRepositoryV1Impl();

        // Proxy 객체 생성
        OrderRepositoryV1 proxy = (OrderRepositoryV1) Proxy
                .newProxyInstance(
                    OrderRepositoryV1.class.getClassLoader(),
                    new Class[]{OrderRepositoryV1.class},
                    new LogTraceBasicHandler(orderRepository, logTrace));

        return proxy;
    }
}

@Import(DynamicBasicProxyConfig.class)
@SpringBootApplication(scanBasePackages = "hello.proxy.app") //주의
public class ProxyApplication {

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

    @Bean
    public LogTrace logTrace(){
        return new ThreadLocalLogTrace();
    }
}
2021-11-28 22:18:58.331  INFO 3357 --- [nio-8080-exec-1] h.p.trace.logtrace.ThreadLocalLogTrace   : [4e72efcd] OrderControllerV1.request()
2021-11-28 22:18:58.333  INFO 3357 --- [nio-8080-exec-1] h.p.trace.logtrace.ThreadLocalLogTrace   : [4e72efcd] |-->OrderServiceV1.orderItem()
2021-11-28 22:18:58.333  INFO 3357 --- [nio-8080-exec-1] h.p.trace.logtrace.ThreadLocalLogTrace   : [4e72efcd] |   |-->OrderRepositoryV1.save()
2021-11-28 22:18:59.338  INFO 3357 --- [nio-8080-exec-1] h.p.trace.logtrace.ThreadLocalLogTrace   : [4e72efcd] |   |<--OrderRepositoryV1.save() time=1005ms
2021-11-28 22:18:59.338  INFO 3357 --- [nio-8080-exec-1] h.p.trace.logtrace.ThreadLocalLogTrace   : [4e72efcd] |<--OrderServiceV1.orderItem() time=1006ms
2021-11-28 22:18:59.339  INFO 3357 --- [nio-8080-exec-1] h.p.trace.logtrace.ThreadLocalLogTrace   : [4e72efcd] OrderControllerV1.request() time=1007ms

특정 메소드에만 부가기능 로직 적용

PatternMatchUtils.simpleMatch 를 사용해 메소드 이름이 조건을 만족하는지 Pattern Matching 한다.

  • pattern : pattern 과 정확히 매칭되면 참
  • pattern* : pattern 으로 시작하면 참
  • *pattern : pattern 으로 끝나면 참
  • *pattern* : pattern 이 있으면 참
public class LogTraceFilterHandler implements InvocationHandler {

    private final Object target;
    private final LogTrace logTrace;
    private final String[] patterns;

    public LogTraceFilterHandler(Object target, LogTrace logTrace, String[] patterns) {
        this.target = target;
        this.logTrace = logTrace;
        this.patterns = patterns;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

        // 메서드 이름 필터
        String methodName = method.getName();

        // save, request, reque*, *est
        // 특정 조건이 맞는 객체에 공통 기능을 적용한다.
        if(!PatternMatchUtils.simpleMatch(patterns, methodName)){
            return method.invoke(target, args);
        }

        TraceStatus status = null;

        try {
            String message = method.getDeclaringClass().getSimpleName() + "." + method.getName() + "()";
            status = logTrace.begin(message);

            // 로직 호출
            Object result = method.invoke(target, args);
            logTrace.end(status);

            return result;
        } catch (Exception ex) {
            logTrace.exception(status, ex);
            throw ex;
        }
    }
}
public class DynamicProxyFilterConfig {

    private static final String[] PATTERNS = {"request*", "order*", "save*"};

    @Bean
    public OrderControllerV1 orderControllerV1(LogTrace logTrace){
        OrderControllerV1 orderControllerV1 = new OrderControllerV1Impl(orderServiceV1(logTrace));
        OrderControllerV1 proxy = (OrderControllerV1) Proxy.newProxyInstance(OrderControllerV1.class.getClassLoader(),
                new Class[]{OrderControllerV1.class},
                new LogTraceFilterHandler(orderControllerV1, logTrace, PATTERNS));

        return proxy;
    }

    @Bean
    public OrderServiceV1 orderServiceV1(LogTrace logTrace){
        OrderServiceV1 orderServiceV1 = new OrderServiceV1Impl(orderRepositoryV1(logTrace));
        OrderServiceV1 proxy = (OrderServiceV1) Proxy.newProxyInstance(OrderServiceV1.class.getClassLoader(),
                new Class[]{OrderServiceV1.class},
                new LogTraceFilterHandler(orderServiceV1, logTrace, PATTERNS));

        return proxy;
    }

    @Bean
    public OrderRepositoryV1 orderRepositoryV1(LogTrace logTrace){
        OrderRepositoryV1 orderRepository = new OrderRepositoryV1Impl();

        OrderRepositoryV1 proxy = (OrderRepositoryV1) Proxy.newProxyInstance(OrderRepositoryV1.class.getClassLoader(),
                new Class[]{OrderRepositoryV1.class},
                new LogTraceFilterHandler(orderRepository, logTrace, PATTERNS));

        return proxy;
    }
}
@Import(DynamicProxyFilterConfig.class)
@SpringBootApplication(scanBasePackages = "hello.proxy.app") //주의
public class ProxyApplication {

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

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