spring中AOP代理的几种方式

部分例子摘自 spring in action

(1)使用ProxyFactoryBean的代理

package chapter4;

public interface Performable {
	public void perform() throws Exception;
}

package chapter4;

import java.util.Random;

public class Artist implements Performable {

	public void perform() throws Exception {
		int num = new Random().nextInt(100);
		
		if(num >= 50) {
			throw new Exception(String.valueOf(num));
		} else {
			System.out.println(num);
		}
	}
}

package chapter4;

public class Audience {
	public Audience() {
	}

	public void takeSeats() {
		System.out.println("The audience is taking their seats.");
	}

	public void turnOffCellPhones() {
		System.out.println("The audience is turning off " + "their cellphones");
	}

	public void applaud() {
		System.out.println("CLAP CLAP CLAP CLAP CLAP");
	}

	public void demandRefund() {
		System.out.println("Boo! We want our money back!");
	}
}

package chapter4;

import java.lang.reflect.Method;

import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.ThrowsAdvice;

public class AudienceAdvice 
	implements MethodBeforeAdvice, AfterReturningAdvice, ThrowsAdvice {
	
	private Audience audience;
	
	public void setAudience(Audience audience) {
		this.audience = audience;
	}

	public void before(Method method, Object[] args, Object target)
		throws Throwable {
		audience.takeSeats();
		audience.turnOffCellPhones();
	}

	public void afterReturning(Object returnValue, Method method, Object[] args,
			Object target) throws Throwable {
		audience.applaud();
	}
	
	public void afterThrowing(Exception ex) {
		audience.demandRefund();
	}
}

 

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
	
	<bean id="audience" class="chapter4.Audience" />
	
	<bean id="audienceAdvice" class="chapter4.AudienceAdvice" >
		<property name="audience" ref="audience" />
	</bean>
	
	<bean id="audienceAdvisor" class="org.springframework.aop.aspectj.AspectJExpressionPointcutAdvisor">
		<property name="advice" ref="audienceAdvice" />
		<property name="expression" value="execution(* *.perform(..))" /> 
	</bean>
	
	<bean id="artistTarget" class="chapter4.Artist" />
	
	<bean id="artist" class="org.springframework.aop.framework.ProxyFactoryBean" >
		<property name="target" ref="artistTarget" />
		<property name="interceptorNames" value="audienceAdvisor" />
		<property name="proxyInterfaces" value="chapter4.Performable" />
	</bean>
</beans>

 (2)隐式使用ProxyFactoryBean的aop代理

DefaultAdvisorAutoProxyCreator实现了BeanPostProcessor，它将自动检查advisor的pointcut是否匹配bean的方法，如果匹配会替换bean为一个proxy，并且应用其advice。

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
	
	<bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator" />
	
	<bean id="audience" class="chapter4.Audience" />
	
	<bean id="audienceAdvice" class="chapter4.AudienceAdvice" >
		<property name="audience" ref="audience" />
	</bean>
	
	<bean id="audienceAdvisor" class="org.springframework.aop.aspectj.AspectJExpressionPointcutAdvisor">
		<property name="advice" ref="audienceAdvice" />
		<property name="expression" value="execution(* *.perform(..))" /> 
	</bean>
	
	<bean id="artist" class="chapter4.Artist" />
</beans>

 (3)使用注解的aop代理

xml中增加了一个<aop:aspectj-autoproxy />，它创建了AnnotationAwareAspectJAutoProxyCreator在spring中，这个类将自动代理匹配的类的放方法。和上个例子中DefaultAdvisorAutoProxyCreator做同样的工作。

package chapter4;

import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;

@Aspect
public class Audience {
	public Audience() {
	}
	
	@Pointcut("execution(* *.perform(..))")
	public void pointcut(){}

	@Before("pointcut()")
	public void takeSeats() {
		System.out.println("The audience is taking their seats.");
	}

	@Before("pointcut()")
	public void turnOffCellPhones() {
		System.out.println("The audience is turning off " + "their cellphones");
	}
	@AfterReturning("pointcut()")
	public void applaud() {
		System.out.println("CLAP CLAP CLAP CLAP CLAP");
	}
	@AfterThrowing("pointcut()")
	public void demandRefund() {
		System.out.println("Boo! We want our money back!");
	}
}

 

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
	
	<aop:aspectj-autoproxy />
	
	<bean id="audience" class="chapter4.Audience" />

	<bean id="artist" class="chapter4.Artist" />
</beans>

 (4)使用aop配置文件的自动代理

采用这种方法，不用加<aop:aspectj-autoproxy />

package chapter4;

import org.aspectj.lang.annotation.Aspect;

@Aspect
public class Audience {
	public Audience() {
	}

	public void pointcut() {
	}

	public void takeSeats() {
		System.out.println("The audience is taking their seats.");
	}

	public void turnOffCellPhones() {
		System.out.println("The audience is turning off " + "their cellphones");
	}

	public void applaud() {
		System.out.println("CLAP CLAP CLAP CLAP CLAP");
	}

	public void demandRefund() {
		System.out.println("Boo! We want our money back!");
	}
}

 

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
	
	<bean id="audience" class="chapter4.Audience" />
	
	<aop:config>
		<aop:aspect ref="audience">
			<aop:before method="takeSeats" pointcut="execution(* *.perform(..))" />
			<aop:before method="turnOffCellPhones" pointcut="execution(* *.perform(..))" />
			<aop:after-returning method="applaud" pointcut="execution(* *.perform(..))" />
			<aop:after-throwing method="demandRefund" pointcut="execution(* *.perform(..))" />
		</aop:aspect>
	</aop:config>

	<bean id="artist" class="chapter4.Artist" />
	
</beans>