Around Advice ( ver. Spring )

[ 이전 글 ]Aspect Oriented Programming ( 2 )

Aspect Oriented Programming ( 2 )

 

Spring Version

 

보조업무의 4종류

• Before Advice ( 앞쪽 )
• After returnning Advice ( 뒤쪽 )
• After throwing Advice ( 예외처리 )
• Around Advice ( 앞, 뒤 )

 

이전 글에서 보인 형태가 Around Advice이다

Spring으로 바꾸자

 

 

XML

 

Proxy객체에 주업무를 실행할 객체와

보조업무를 실행할 객체를 지시한다

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:util="http://www.springframework.org/schema/util"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd">
		
	
	<bean id="target" class="spring.aop.entity.ScoreExam" p:kor="1"  p:eng="1" p:math="1" p:com="1"/>
	<bean id="logAroundAdvice" class="spring.aop.advice.LogAroundAdvice"/>
	<bean id="proxy" class="org.springframework.aop.framework.ProxyFactoryBean">
		<property name="target" ref="target"/>
		<property name="interceptorNames">
			<list>
				<value>logAroundAdvice</value>
			</list>
		</property>
	</bean>
	
</beans>

실행부

아래 주석된 부분으로 실행시 Proxy 실행( 주업무 + 보조업무 )

현 상태에서는 주업무만 실행된다

package spring.aop;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import spring.aop.entity.Exam;

public class Program {

	public static void main(String[] args) {
		
		ApplicationContext context = 
        			new ClassPathXmlApplicationContext("spring/aop/setting.xml");
		
		Exam exam = 
        //      (Exam) context.getBean("target");
                (Exam) context.getBean("proxy");
		
		System.out.printf("total is %d\n", exam.total());
		System.out.printf("avg is %.2f\n", exam.avg());
        }
}

Proxy

Java Project에서는 invoke()

Spring에서는 proceed()

package spring.aop.advice;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

public class LogAroundAdvice implements MethodInterceptor {

	@Override
	public Object invoke(MethodInvocation invocation) throws Throwable {
		long start = System.currentTimeMillis();

		Object result = invocation.proceed();

		long end = System.currentTimeMillis();
		String message = (end - start) + "ms 시간이 걸렸습니다.";

		System.out.println(message);
		return result;
	}

}

interface

package spring.aop.entity;

public interface Exam {
	int total();
	float avg();
}

구현 클래스

package spring.aop.entity;

public class ScoreExam implements Exam {

	private int kor;
	private int eng;
	private int math;
	private int com;

	public ScoreExam() { }

	public ScoreExam(int kor, int eng, int math, int com) {
		this.kor = kor;
		this.eng = eng;
		this.math = math;
		this.com = com;
	}

	public void setKor(int kor) {this.kor = kor;}

	public void setEng(int eng) {this.eng = eng;}

	public void setMath(int math) {this.math = math;}

	public void setCom(int com) {this.com = com;}

	@Override
	public int total() {
		int result = kor + eng + math + com;
		
		try {
        // 쓰레드를 잠시 정시시켜 강제로 작업시간을 늘렸다
			Thread.sleep(200);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		return result;
		
	}

	@Override
	public float avg() {
		
		float result = total() / 4.0f;
		
		return result;
	}

	@Override
	public String toString() {
		return "ScoreExam [kor=" + kor + ", eng=" + eng + 
				", math=" + math + ", com=" + com + "]";
	}
}