19.스프링으로 aop구현하기

스프링으로 AOP를 구현하기

• 프락시 클래스에 구현되는 Cross-cutting Concern

 

스프링은 AOP을 4가지로 구분

Before:앞에만 필요한 AOP

After returnning: 뒤에만 필요한 AOP

After throwing: 예외처리할떄 필요한 AOP

Around: 모두 필요한 AOP - Advice(타겟에 제공할 부가기능을 가진다)

 

• Around 사용해보기

<bean id ="target" class ="spring.aop.entity.NewlecExam" 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" />
	<!-- 핸들러 넣어준다  -->
	<property name="interceptorNames">
	<list>
		<value>logAroundAdvice</value>
	</list>
	
	</property>
	</bean>

 

따로 프락시 클래스를 만들어 생성한다

public class LogAroundAdvice implements MethodInterceptor {

	// 외부적인 요소와 연관 되지 않게 해결한다
	@Override
	public Object invoke(MethodInvocation invocation) throws Throwable {
		long start = System.currentTimeMillis();
		Object result = invocation.proceed();

		long end = System.currentTimeMillis();

		String massage = (end - start) + "ms 시간 걸렸습니다";

		System.out.println(massage);

		return result;
	}

}

public class Program {
	public static void main(String[] args) {

		ApplicationContext context = new ClassPathXmlApplicationContext("spring/aop/setting.xml");

		Exam proxy = (Exam) context.getBean("proxy");

		System.out.printf("total is %d\n", proxy.total());
		System.out.printf("avg is %f\n", proxy.avg());

 

exam으로 바꿔서 사용해볼 수도 있다

public static void main(String[] args) {

		ApplicationContext context = new ClassPathXmlApplicationContext("spring/aop/setting.xml");

		Exam exam = (Exam) context.getBean("exam");

		System.out.printf("total is %d\n", exam.total());
		System.out.printf("avg is %f\n", exam.avg());

<bean id ="exam" class ="spring.aop.entity.NewlecExam" p:kor="1" p:eng="1" p:math="1" p:com="1"/>

total is 4
avg is 1.000000