During development, there are a lot of use Spring Aop, when Oriented Programming, we will use <aop: aspect>; during transaction management, we will use <aop: advisor>. So, for the <aop: aspect> and: the difference <aop advisor>, specifically what is it?
As for the difference between the two, there is a lot of information online, but can not seem to make it clear.
First, we need a clear concept of both.
- <Aop: aspect>: defining aspects (including notification section and tangent point)
- <Aop: advisor>: define notifier (notifier like section, including notification and tangent point)
Below, we list some difference between the two.
1, different implementations
<Aop: aspect> the definition section, only need to define the general bean on the line, defined <aop: advisor> notification referenced in the notice must implement the Advice interface.
Here we illustrate.
First, we define a Human Interface Sleepable and implement this interface, the code is as follows:
public interface Sleepable {
public void sleep();
}
public class Human implements Sleepable {
@Override
public void sleep() {
System.out.println("我要睡觉了！");
}
}
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The following is <aop: advisor> implementations:
//定义通知
public class SleepHelper implements MethodBeforeAdvice,AfterReturningAdvice{
@Override
public void before(Method arg0, Object[] arg1, Object arg2)
throws Throwable {
System.out.println("睡觉前要脱衣服！");
}
@Override
public void afterReturning(Object arg0, Method arg1, Object[] arg2,
Object arg3) throws Throwable {
System.out.println("起床后要穿衣服！");
}
}
//aop配置
<bean id="sleepHelper" class="com.ghs.aop.SleepHelper"></bean>
<aop:config>
<aop:pointcut expression="execution(* *.sleep(..))" id="sleepPointcut"/>
<aop:advisor advice-ref="sleepHelper" pointcut-ref="sleepPointcut"/>
</aop:config>
<bean id="human" class="com.ghs.aop.Human"/>
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The following is <aop: aspect> implementations:
//定义切面
public class SleepHelperAspect{
public void beforeSleep(){
System.out.println("睡觉前要脱衣服！");
}
public void afterSleep(){
System.out.println("起床后要穿衣服！");
}
}
//aop配置
<bean id="sleepHelperAspect" class="com.ghs.aop.SleepHelperAspect"></bean>
<aop:config>
<aop:pointcut expression="execution(* *.sleep(..))" id="sleepPointcut"/>
<aop:aspect ref="sleepHelperAspect">
<!--前置通知-->
<aop:before method="beforeSleep" pointcut-ref="sleepPointcut"/>
<!--后置通知-->
<aop:after method="afterSleep" pointcut-ref="sleepPointcut"/>
</aop:aspect>
</aop:config>
<bean id="human" class="com.ghs.aop.Human"/>
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Test code is as follows:
public class TestAOP {
public static void main(String[] args) {
method1();
// method2();
}
private static void method1() {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext1.xml");
Sleepable sleeper = (Sleepable) context.getBean("human");
sleeper.sleep();
}
private static void method2() {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext2.xml");
Sleepable sleeper = (Sleepable) context.getBean("human");
sleeper.sleep();
}
//执行结果
睡觉前要脱衣服！
我要睡觉了！
起床后要穿衣服！
}
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2, the use of different scenes
<Aop: advisor> mostly used for transaction management.
E.g:
<!-- 会重复读，不会脏读事务 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*" timeout="120" propagation="REQUIRED" rollback-for="Exception" />
</tx:attributes>
</tx:advice>
<aop:config proxy-target-class="true">
<aop:pointcut id="txPointCut" expression="..."/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut" />
</aop:config>
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<Aop: aspect> mostly used for logging, caching
In fact, whether it is <aop: advisor> or <aop: aspect> final implementation logic is the same.
Summary:
As can be seen, <aop: advisor> and <aop: aspect> in fact will be notified and cut the package, the principle is basically the same, just different ways to use it.
Attachment:
understanding of this problem, in fact, has not been an in-depth understanding, we recommend the following several blog posts, share their hopes.
http://www.iteye.com/problems/69785
http://blog.sina.com.cn/s/blog_5198c7370100hw1p.html
http://blog.csdn.net/huitoukest/article/details/46469177
HTTP: / /www.tz365.cn/ask/shenghuo/2016/0804/739237.html
https://zhidao.baidu.com/question/371238289198208804.html