pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>cn.et</groupId>
  <artifactId>SpringAopPrinciple</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <dependencies>
	<dependency>
	    <groupId>org.springframework</groupId>
	    <artifactId>spring-beans</artifactId>
	    <version>4.3.9.RELEASE</version>
	</dependency>
	<dependency>
	    <groupId>org.springframework</groupId>
	    <artifactId>spring-context</artifactId>
	    <version>4.3.9.RELEASE</version>
	</dependency>
	<dependency>
	    <groupId>org.springframework</groupId>
	    <artifactId>spring-aop</artifactId>
	    <version>4.3.9.RELEASE</version>
	</dependency>
	<!-- JUnit Java語言的單元測試框架 -->
	<dependency>
	    <groupId>junit</groupId>
	    <artifactId>junit</artifactId>
	    <version>4.12</version>
	    <scope>test</scope>
	</dependency>
	<!-- Cglib 提供強大的動態代理 -->
	<dependency>
	    <groupId>cglib</groupId>
	    <artifactId>cglib</artifactId>
	    <version>2.2</version>
	</dependency>
  </dependencies>
  <build>
  	<plugins>
  		<!-- 指定JDK版本和編碼的外掛 -->
  		<plugin>
  			<groupId>org.apache.maven.plugins</groupId>
  			<artifactId>maven-compiler-plugin</artifactId>
  			<configuration>
  				<source>1.7</source>
				<target>1.7</target>
				<encoding>UTF-8</encoding>
  			</configuration>
  		</plugin>
  	</plugins>
  </build>
</project>
 

package cn.et.dao;

public interface UserDao {
	public void addUser();
}

package cn.et.dao.impl;

import cn.et.dao.UserDao;

public class UserDaoImpl implements UserDao {
	public void addUser(){
		System.out.println("新增使用者");
	}
}

package cn.et.dao.impl;

public class StudentDao {
	public void addStudent(){
		System.out.println("新增學生");
	}
}
 

package cn.et.utils;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

public class MyInvocationHandler implements InvocationHandler{
	private Object targetObj;
	public MyInvocationHandler(Object targetObj){
		this.targetObj = targetObj;
	}

	@Override
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
		System.out.println("許可權驗證");
		Object resultObj = method.invoke(targetObj, args);
		System.out.println("日誌記錄");
		return resultObj;
	}
}
 

package cn.et.utils;

import java.lang.reflect.Method;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class CglibProxy implements MethodInterceptor {
	private Enhancer enhancer = new Enhancer();  
	public Object getProxy(Class clazz){  
		enhancer.setSuperclass(clazz);  
		enhancer.setCallback(this);  
		//通過位元組碼技術動態建立子類例項  
	    return enhancer.create();  
	}  
	//實現MethodInterceptor介面方法  
	public Object intercept(Object obj, Method method, Object[] args,  
	    MethodProxy proxy) throws Throwable {  
	    System.out.println("許可權驗證");  
	    Object result = proxy.invokeSuper(obj, args);  
	    System.out.println("日誌記錄");  
	    return result;  
	}  
}

package cn.et.utils;



import java.lang.reflect.Proxy;

import org.junit.Test;

import cn.et.dao.UserDao;
import cn.et.dao.impl.StudentDao;
import cn.et.dao.impl.UserDaoImpl;

public class Checkout {
	@Test
	public void Testing(){
		UserDao userDao = new UserDaoImpl();
		/*
		Spring AOP(面向切面程式設計)，擴充套件功能不修改原始碼實現，採用橫向抽取機制，取代了傳統縱向繼承體系重複性程式碼
		橫向抽取機制，底層使用動態代理方式實現
			針對有介面的情況時使用JDK中的java.lang.reflect類庫提供的動態代理
			針對沒有介面的情況時,使用Cglib框架提供的動態代理
		*/
		MyInvocationHandler handler = new MyInvocationHandler(userDao);
		UserDao proxyUserDao = (UserDao) Proxy.newProxyInstance(userDao.getClass().getClassLoader(),userDao.getClass().getInterfaces(),handler);
		proxyUserDao.addUser();
		
		System.out.println("。。。。。。。。。。。。。");
		
		CglibProxy proxy = new CglibProxy();  
	    StudentDao proxyImp = (StudentDao)proxy.getProxy(StudentDao.class);  
	    proxyImp.addStudent();  
		
	}
}