一个简单的Spring的AOP例子

package aop;
/**  
 * 目标对象的接口 
 */ 
public interface Student {
	public void addStudent(String name);
}

package aop;
/**  
 * 目标对象 
 */ 
public class StudentImpl implements Student {

	public void addStudent(String name) {
		System.out.println(" 欢迎  " + name + "  你加入Spring家庭! ");
	}
}

package aop;

import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;

/**
 * 前置通知
 */
public class BeforeAdvice implements MethodBeforeAdvice {

	public void before(Method method, Object[] args, Object target)
			throws Throwable {

		System.out.println(" 这是BeforeAdvice类的before方法. ");

	}
}

package aop;

import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;

/**
 * 后置通知
 */
public class AfterAdvice implements AfterReturningAdvice {

	public void afterReturning(Object returnValue, Method method,
			Object[] args, Object target) throws Throwable {
		System.out.println("这是AfterAdvice类的afterReturning方法.");
	}

}

package aop;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
/**
 * 环绕通知
 */
public class CompareInterceptor implements MethodInterceptor {
	public Object invoke(MethodInvocation invocation) throws Throwable {
		Object result = null;
		String stu_name = invocation.getArguments()[0].toString();
		if (stu_name.equals("dragon")) {
			// 如果学生是dragon时,执行目标方法,
			result = invocation.proceed();
		} else {
			System.out.println("此学生是" + stu_name + "而不是dragon,不批准其加入.");
		}
		return result;
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
	<bean id="beforeAdvice" class="aop.BeforeAdvice"></bean>
	<bean id="afterAdvice" class="aop.AfterAdvice"></bean>
	<bean id="compareInterceptor" class="aop.CompareInterceptor"></bean>
	<bean id="studenttarget" class="aop.StudentImpl"></bean>
	<bean id="student"
		class="org.springframework.aop.framework.ProxyFactoryBean">
		<property name="proxyInterfaces">
			<value>aop.Student</value>
		</property>
		<property name="interceptorNames">
			<list>
				<value>beforeAdvice</value>
				<value>afterAdvice</value>
				<value>compareInterceptor</value>
			</list>
		</property>
		<property name="target">
			<ref bean="studenttarget" />
		</property>
	</bean>

</beans>

package aop;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
/**
 * 测试代码
 */
public class Test {

	public static void main(String[] args) {
		 ApplicationContext ctx = new FileSystemXmlApplicationContext("/src/applicationContext.xml");
		 Student s = (Student)ctx.getBean("student");
		 s.addStudent("aaa");
	}

}

评论

1 楼 mp_juan 2010-04-14  

不错，讲的还比较细致