前言
Spring AOP的实现方法很多，在项目开发中具体采用什么方式，需要按实际情况来选择，每一种的用法，有其一定的实用价值，所以本文将各种使用方法进行了具体实现。主要包括Advice的before、after、throwing、around四种拦截方式的实现，如何进行正则匹配，自动化代理及AspectJ注解形式的实现。
AOP的定义
Spring AOP(Aspect-oriented programming) 面向切面编程，是一种特殊的拦截器，将一组程序中的公共部分抽离出来进行单独管理，降低程序的耦合度，aop和oo互为补充，面向对象编程将程序分解成各个层次的对象，而面向切面编程将程序运行过程分解成各个切面。也可以这样理解，面向对象编程是从静态角度考虑程序结构，面向切面编程是从动态角度考虑程序运行过程。
AOP中6个要素
（1）通知（增强）Advice
通知定义了切面是什么以及何时使用，应该应用在某个方法被调用之前？之后？还是抛出异常时？等等。
（2）连接点 Join point
连接点是在应用执行过程中能够插入切面的一个点。这个点可以是调用方法时，抛出异常时，甚至修改一个字段时。切面代码可以利用这些点插入到应用的正常流程中，并添加新的行为。
（3）切点 Pointcut
切点有助于缩小切面所通知的连接点的范围。如果说通知定义了切面的“什么”和“何时”的话，那么切点就定义了“何处”，切点会匹配通知所要织入的一个或多个连接点，一般常用正则表达式
定义所匹配的类和方法名称来指定这些切点。
（4）切面 Aspect
切面是通知和切点的结合。通知和切点定义了切面的全部内容——它是什么，在何时何处完成其功能。
（5）引入 Introduction
引入允许我们向现有的类添加新方法或属性，从而无需修改这些现有类的情况下，让他们具有新的行为和状态。
（6）织入 Weaving
在过去我常常把织入与引入的概念混淆，我是这样来辨别的，“引入”我把它看做是一个定义，也就是一个名词，而“织入”我把它看做是一个动作，一个动词，也就是切面在指定的连接点被织
入到目标对象中。
AOP用法总结
（1）Before advice 在方法执行前执行。
（2）After returning advice 在方法执行后返回一个结果后执行。
（3）After throwing advice 在方法执行过程中抛出异常的时候执行。
（4）Around advice 在方法执行前后和抛出异常时执行，相当于综合了以上三种通知。
（5）基于正则表达式，对符合匹配规则类或方法进行拦截处理。
（6）基于自动代理，简少配置。
（7）基于AspectJ注解形式,包括execution 表达式、@DeclareParents 注解、自动代理。
实例
1. Before advice 在方法执行前执行
创建Product产品类
package com.jk.work.aopone;
/**
* Title: 产品
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-18
* @version: 1.0
*/
public class Product {
private String name;
private String type;
private int size; public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getType() {
return type;
} public void setType(String type) {
this.type = type;
} public int getSize() {
return size;
} public void setSize(int size) {
this.size = size;
} public void printName(){
System.out.println("Product name "+ this.name);
} public void printType(){
System.out.println("Product type "+this.type);
} public void printThrowException(){
throw new IllegalArgumentException();
}
}
创建BeforeMethod类
package com.jk.work.aopone;
import org.springframework.aop.MethodBeforeAdvice;
import java.lang.reflect.Method;
/**
* Title: BeforeMethod
* Description: 在方法执行前执行
*
* @author jihuan
* @create 2017-05-19
* @version: 1.0
*/
public class BeforeMethod implements MethodBeforeAdvice {
@Override
public void before(Method method, Object[] objects, Object o) throws Throwable {
System.out.println("Before Method");
System.out.println("--------------------");
}
}
创建配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="product" class="com.jk.work.aopone.Product">
<property name="name" value="p2p p2p p2p" />
<property name="type" value="one year"/>
<property name="size" value="30000" />
</bean> <bean id="beforeMethodBean" class="com.jk.work.aopone.BeforeMethod" /> <bean id="productProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="product"/>
<property name="interceptorNames">
<list>
<value>beforeMethodBean</value>
</list>
</property>
<property name="proxyTargetClass" value="true"/> <!-- true 表 cglib,false 为jdkproxy(需要property 引入接口)-->
</bean>
</beans>
创建测试类Test.java
package com.jk.work.aopone;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-19
* @version: 1.0
*/
public class Test { public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
Product product = (Product) context.getBean("productProxy");
System.out.println("---------------------");
product.printName();
System.out.println("---------------------");
product.printType();
System.out.println("----------------------");
try{
product.printThrowException();
}catch(Exception e){
}
}
}
运行结果：
---------------------
Before Method
--------------------
Product name p2p p2p p2p
---------------------
Before Method
--------------------
Product type one year
----------------------
Before Method
--------------------
测试类可以采用编程式调用，简单实现：
package com.jk.work.aopone;
import org.springframework.aop.framework.ProxyFactory;
/**
* Title: 编程式
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-19 00:26
* @version: 1.0
*/
public class Test2 { public static void main(String[] args) {
ProxyFactory proxyFactory=new ProxyFactory() ;
Product product1=new Product();
product1.setName("p2p");
proxyFactory.setTarget(product1);
proxyFactory.addAdvice(new BeforeMethod());
Product product=(Product)proxyFactory.getProxy();
product.printName();
}
}
运行结果：
Before Method
--------------------
Product name p2p
2.After returning advice 方法之后执行
创建AfterMethod类
package com.jk.work.aopone;
import org.springframework.aop.AfterReturningAdvice;
import java.lang.reflect.Method;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-19 00:09
* @version: 1.0
*/
public class AfterMethod implements AfterReturningAdvice {
@Override
public void afterReturning(Object o, Method method, Object[] objects, Object o1) throws Throwable {
System.out.println("-------------------");
System.out.println("After method ");
}
}
创建配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="product" class="com.jk.work.aopone.Product">
<property name="name" value="p2p p2p p2p" />
<property name="type" value="one year"/>
<property name="size" value="30000" />
</bean> <bean id="afterMethodBean" class="com.jk.work.aopone.AfterMethod" /> <bean id="productProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="product"/>
<property name="interceptorNames">
<list>
<value>afterMethodBean</value>
</list>
</property>
<property name="proxyTargetClass" value="true"/> <!-- true 表 cglib,false 为jdkproxy(需要property 引入接口)-->
</bean>
</beans>
创建测试类复用Test.java
运行结果：
---------------------
Product name p2p p2p p2p
-------------------
After method
---------------------
Product type one year
-------------------
After method
----------------------
3. After throwing advice 在方法执行过程中抛出异常的时候执行
创建ThrowException类
package com.jk.work.aopone;
import org.springframework.aop.ThrowsAdvice;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-19
* @version: 1.0
*/
public class ThrowException implements ThrowsAdvice {
public void afterThrowing(IllegalArgumentException e) throws Throwable{
System.out.println("after Throwing Exception");
}
}
创建配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="product" class="com.jk.work.aopone.Product">
<property name="name" value="p2p p2p p2p" />
<property name="type" value="one year"/>
<property name="size" value="30000" />
</bean> <bean id="throwException" class="com.jk.work.aopone.ThrowException" /> <bean id="productProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="product"/>
<property name="interceptorNames">
<list>
<value>throwException</value>
</list>
</property>
<property name="proxyTargetClass" value="true"/> <!-- true 表 cglib,false 为jdkproxy(需要property 引入接口)-->
</bean>
</beans>
运行结果
---------------------
Product name p2p p2p p2p
---------------------
Product type one year
----------------------
after Throwing Exception
4. Around advice 在方法执行前后和抛出异常时执行，相当于综合了以上三种通知
创建AroundMethod类
package com.jk.work.aopone;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import java.util.Arrays;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-19
* @version: 1.0
*/
public class AroundMethod implements MethodInterceptor {
@Override
public Object invoke(MethodInvocation methodInvocation) throws Throwable {
System.out.println("method name:" + methodInvocation.getMethod().getName());
System.out.println("method arguments" + Arrays.toString(methodInvocation.getArguments()));
System.out.println("Around method : before ");
try{
Object result = methodInvocation.proceed();
System.out.println("Around method : after ");
return result;
}catch(IllegalArgumentException e){
System.out.println("Around method : throw an exception ");
throw e;
}
}
}
创建配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="product" class="com.jk.work.aopone.Product">
<property name="name" value="p2p p2p p2p" />
<property name="type" value="one year"/>
<property name="size" value="30000" />
</bean> <bean id="aroundMethod" class="com.jk.work.aopone.AroundMethod" /> <bean id="productProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="product"/>
<property name="interceptorNames">
<list>
<value>aroundMethod</value>
</list>
</property>
<property name="proxyTargetClass" value="true"/> <!-- true 表 cglib,false 为jdkproxy(需要property 引入接口)-->
</bean>
</beans>
运行结果
---------------------
method name:printName
method arguments[]
Around method : before
Product name p2p p2p p2p
Around method : after
---------------------
method name:printType
method arguments[]
Around method : before
Product type one year
Around method : after
----------------------
method name:printThrowException
method arguments[]
Around method : before
Around method : throw an exception
5. 基于正则表达式的实现
采用RegexpMethodPointcutAdvisor来实现。采用的正则匹配规则，大概有四点，举例说明：
com\.service\..* 和 com\.service\..*Service\..* 和 .*get.* 和 .get.*
第一个表达式匹配的应该是com.service包下的所有方法
第二个表达式匹配的应该是com.service包下所有类名以Service结尾的所有方法
第三个表达式匹配的应该是所有类中含有get的方法
第四个表达式匹配的应该是所有类中以get为前缀的方法
具体如何实现，见下方实例：
创建Garden接口
package com.jk.work.aoptwo; /**
* Created by jihuan on 17/5/20.
*/
public interface Garden { void fruitPlant(); void fruitGrow(); void fruitHarvest();
}
创建Garden实现类
package com.jk.work.aoptwo;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
public class AppleGarden implements Garden{
@Override
public void fruitPlant() {
System.out.println("Apple plant...");
} @Override
public void fruitGrow() {
System.out.println("Apple grow...");
} @Override
public void fruitHarvest() {
System.out.println("Apple harvest...");
}
}
创建拦截类，采用MethodInterceptor，实现方法前后拦截
package com.jk.work.aoptwo;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
public class GardenAroundAdvice implements MethodInterceptor {
@Override
public Object invoke(MethodInvocation methodInvocation) throws Throwable {
before();
Object result=methodInvocation.proceed();
after();
return result;
}
private void before(){
System.out.println("before......");
}
private void after(){
System.out.println("after......");
}
}
创建配置文件，AppleGarden下所有以fruit开头的方法进行切面拦截
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <!--果园-->
<bean id="appleGarden" class="com.jk.work.aoptwo.AppleGarden" />
<bean id="gardenAroundAdvice" class="com.jk.work.aoptwo.GardenAroundAdvice" />
<bean id="gardenAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="gardenAroundAdvice" />
<property name="pattern" value="com.jk.work.aoptwo.AppleGarden.fruit.*" />
</bean> <bean id="productProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="appleGarden"/>
<property name="interceptorNames">
<list>
<value>gardenAdvisor</value>
</list>
</property>
<property name="proxyTargetClass" value="true"/> <!-- true 表 cglib,false 为jdkproxy(需要property 引入接口)-->
</bean>
</beans>
测试类
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
public class Test {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("productProxy");
System.out.println("----------1-----------");
appleGarden.fruitPlant();
System.out.println("----------2----------");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest(); }
}
运行效果：
----------1-----------
before......
Apple plant...
after......
----------2----------
before......
Apple grow...
after......
----------3-----------
before......
Apple harvest...
after...... Process finished with exit code 0
6. 基于自动代理的实现
采用自动代理的好处，可以减少配置，简化开发，spring的自动代理，采用了三种方式：
1）Advisor形式，实现类为DefaultAdvisorAutoProxyCreator；
2）Bean形式，实现类为BeanNameAutoProxyCreator；
3）AspjectJ注解形式，实现方式是@Aspect。
具体实例
Advisor形式，实现类为DefaultAdvisorAutoProxyCreator
创建sprng-aop.xml 配置
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<!--果园-->
<bean id="appleGarden" class="com.jk.work.aoptwo.AppleGarden" />
<bean id="gardenAroundAdvice" class="com.jk.work.aoptwo.GardenAroundAdvice" />
<bean id="gardenAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="gardenAroundAdvice" />
<property name="pattern" value="com.jk.work.aoptwo.AppleGarden.fruit.*" />
</bean>
<!--自动代理-->
<bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator">
<property name="optimize" value="true"/><!-- true 自动寻找代理类，有接口，使用jdkproxy，否则采用cglib-->
</bean>
</beans>
测试类：
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
public class Test2 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("appleGarden");
System.out.println("----------1-----------");
appleGarden.fruitPlant();
System.out.println("----------2----------");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest();
}
}
运行效果
----------1-----------
before......
Apple plant...
after......
----------2----------
before......
Apple grow...
after......
----------3-----------
before......
Apple harvest...
after......
Bean形式，实现类为BeanNameAutoProxyCreator
创建spring-aop.xml 配置
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<!--果园-->
<bean id="appleGarden" class="com.jk.work.aoptwo.AppleGarden" />
<bean id="gardenAroundAdvice" class="com.jk.work.aoptwo.GardenAroundAdvice" />
<bean id="gardenAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="gardenAroundAdvice" />
<property name="pattern" value="com.jk.work.aoptwo.AppleGarden.fruit.*" />
</bean> <!--自动代理-->
<bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<property name="beanNames" value="*Garden" />
<property name="interceptorNames" value="gardenAdvisor"/>
<property name="optimize" value="true"/> <!--true 使用jdkproxy，false 采用cglib-->
</bean>
</beans>
测试类：
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
public class Test2 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("appleGarden");
System.out.println("----------1-----------");
appleGarden.fruitPlant();
System.out.println("----------2----------");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest();
}
}
运行效果
----------1-----------
before......
Apple plant...
after......
----------2----------
before......
Apple grow...
after......
----------3-----------
before......
Apple harvest...
after......
AspjectJ注解形式，实现类是AnnotationAwareAspectJAutoProxyCreator，在AspjectJ注解部分说明。
7. AspectJ注解
AspectJ注解方式，采用execution表达式进行切面拦截
创建spring-aop配置
<?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: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/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="com.*"/>
<!--果园-->
<bean id="appleGarden" class="com.jk.work.aoptwo.AppleGarden" />
<bean id="gardenAroundAdvice" class="com.jk.work.aoptwo.GardenAroundAdvice" />
<bean id="gardenAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="gardenAroundAdvice" />
<property name="pattern" value="com.jk.work.aoptwo.AppleGarden.fruit.*" />
</bean>
<!--aspectj-->
<aop:aspectj-autoproxy proxy-target-class="true"/>
</beans>
创建AroundAspect 拦截类
package com.jk.work.aoptwo;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component; /**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
@Aspect
@Component
public class AroundAspect {
@Around("execution(* com.jk.work.aoptwo.AppleGarden.*(..))")
public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable{
handleBefore();
Object rs=proceedingJoinPoint.proceed();
handleAfter();
return rs;
} private void handleBefore(){
System.out.println("=====before=====");
}
private void handleAfter(){
System.out.println("=====after=====");
}
}
测试类
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20
* @version: 1.0
*/
public class Test2 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("appleGarden");
System.out.println("----------1-----------");
appleGarden.fruitPlant();
System.out.println("----------2----------");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest();
}
}
运行效果
----------1-----------
=====before=====
Apple plant...
=====after=====
----------2----------
=====before=====
Apple grow...
=====after=====
----------3-----------
=====before=====
Apple harvest...
=====after=====
AspectJ @DeclareParents 注解，目标是对于一个已有的类引入新的接口，可以使用另一个接口类的功能，属于一种对类的扩展
创建新的接口Worker类
package com.jk.work.aoptwo; /**
* Created by jihuan on 17/5/20.
*/
public interface Worker { void work(String task);
}
创建Worker的实现类
package com.jk.work.aoptwo;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20 17:43
* @version: 1.0
*/
public class AppleWorker implements Worker{
@Override
public void work(String task) {
System.out.println("start work..."+task);
}
}
创建拦截器AroundAspect2
package com.jk.work.aoptwo;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.DeclareParents;
import org.springframework.stereotype.Component; /**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20 17:40
* @version: 1.0
*/
@Aspect
@Component
public class AroundAspect2 {
@DeclareParents(value = "com.jk.work.aoptwo.AppleGarden",defaultImpl =AppleWorker.class )
private Worker worker;
}
spring-aop.xml的配置
<?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: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/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="com.*"/>
<!--果园-->
<bean id="appleGarden" class="com.jk.work.aoptwo.AppleGarden" />
<bean id="gardenAroundAdvice" class="com.jk.work.aoptwo.GardenAroundAdvice" />
<bean id="gardenAdvisor" class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
<property name="advice" ref="gardenAroundAdvice" />
<property name="pattern" value="com.jk.work.aoptwo.AppleGarden.fruit.*" />
</bean>
<!--aspectj-->
<aop:aspectj-autoproxy proxy-target-class="true"/>
</beans>
创建测试类
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext; /**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20 17:48
* @version: 1.0
*/
public class Test3 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("appleGarden");
Worker worker=(Worker)appleGarden;
System.out.println("----------1-----------");
worker.work("plant");
appleGarden.fruitPlant();
System.out.println("----------2----------");
worker.work("watering");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest();
worker.work("Harvest");
}
}
运行效果
----------1-----------
start work...plant
Apple plant...
----------2----------
start work...watering
Apple grow...
----------3-----------
Apple harvest...
start work...Harvest
AspjectJ注解自动代理方式的实现
创建拦截类
package com.jk.work.aoptwo;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20 17:21
* @version: 1.0
*/
@Aspect
@Component
public class AroundAspect {
public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable{
handleBefore();
Object rs=proceedingJoinPoint.proceed();
handleAfter();
return rs;
} private void handleBefore(){
System.out.println("=====before=====");
}
private void handleAfter(){
System.out.println("=====after=====");
}
}
spring-aop.xml 配置
<?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: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/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="com.*"/> <!--aspectj-->
<aop:config>
<aop:aspect ref="aroundAspect">
<aop:around method="around" pointcut="execution(* com.jk.work.aoptwo.AppleGarden.*(..))"/>
</aop:aspect>
</aop:config>
<aop:aspectj-autoproxy proxy-target-class="true"/>
</beans>
测试类
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20 11:04
* @version: 1.0
*/
public class Test2 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("appleGarden");
System.out.println("----------1-----------");
appleGarden.fruitPlant();
System.out.println("----------2----------");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest();
}
}
运行效果
package com.jk.work.aoptwo;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Title: 类的主题（开发人员填写）
* Description: 该类的功能
*
* @author jihuan
* @create 2017-05-20 11:04
* @version: 1.0
*/
public class Test2 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring/spring-aop.xml");
AppleGarden appleGarden = (AppleGarden) context.getBean("appleGarden");
System.out.println("----------1-----------");
appleGarden.fruitPlant();
System.out.println("----------2----------");
appleGarden.fruitGrow();
System.out.println("----------3-----------");
appleGarden.fruitHarvest();
}
}
总结
AOP的用法较多，熟悉每一种用法，能更好的在项目中发挥作用。AOP其实就是一种拦截器，底层采用JDKProxy动态代理和Cglib实现动态代理。对于有接口的形式采用JDKProxy加载处理目标对象。对于没有接口的普通类采用Cglib进行对象的拦截对出。JDKProxy的底层是java反射，Cglib的底层是调asm开源包。
如需转载，请标明本文作者：源码在深山，出处：博客园，原文链接：http://www.cnblogs.com/love-jk/p/spring-api.html
参考：
1） http://blog.csdn.net/topwqp/article/details/8695180
2) http://www.cnblogs.com/zhaozihan/p/5953063.html
3）《轻量级Java EE企业应用实战》第三版