Decorator Pattern 3 - chain

1. 실행 시간을 측정하는 Decorator

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• Decorator는 하나 추가하여 시간을 측정하는 기능을 추가해보자.

 

2. TimeDecorator

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• TimeDecorator는 timeDecorator가 호출된 시간과 다음 Component가 종료된 시간을 측정.

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class TimeDecorator implements Component{

    private Component component;

    public TimeDecorator(Component component) {
        this.component = component;
    }

    @Override
    public String operation() {
        log.info("TimeDecorator 실행");
        long startTime = System.currentTimeMillis();
        String result = component.operation();
        long endTime = System.currentTimeMillis();
        long resultTime = endTime - startTime;
        log.info("TimeDecorator 종료, resultTime =  {} ms", resultTime);
        return result;
    }
}

 

3. Test

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@Test
void decorator2(){
    Component realComponent = new RealComponent();
    Component messageDecorator = new MessageDecorator(realComponent);
    Component timeDecorator = new TimeDecorator(messageDecorator);
    DecoratorPatternClient client = new DecoratorPatternClient(timeDecorator);

    client.execute();

}

23:13:01.512 [main] INFO hello.proxy.pureproxy.decorator.code.TimeDecorator - TimeDecorator 실행
23:13:01.514 [main] INFO hello.proxy.pureproxy.decorator.code.MessageDecorator - MessageDecorator 실행
23:13:01.514 [main] INFO hello.proxy.pureproxy.decorator.code.RealComponent - Real Component 실행
23:13:01.520 [main] INFO hello.proxy.pureproxy.decorator.code.MessageDecorator - MessageDecorator 꾸미기 적용 : data --> ***data***
23:13:01.523 [main] INFO hello.proxy.pureproxy.decorator.code.TimeDecorator - TimeDecorator 종료, resultTime =  8 ms
23:13:01.523 [main] INFO hello.proxy.pureproxy.decorator.code.DecoratorPatternClient - result=***data***

 

4. 정리

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Client 코드의 변경 없이 proxy의 추가로 기능을 추가했다. -> Decorator 특징

 

 

5. GitHub : 211228 DecoratorPattern 3

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GitHub - bsh6463/Spring_Advanced_2