Spring进阶之路(11)-使用Aspectj切面配置和XML配置文件方式实现切面编程

Posted 2020-06-23 低调的洋仔

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异常

在使用的时候，遇到了部分的异常，我用的是最新的Spring版本，Spring-4.2.5版本的，首先确保你的配置文件中引入了下面红色部分。

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      <span style="color:#ff0000;"> xmlns:aop="http://www.springframework.org/schema/aop"</span>
       xsi:schemaLocation="
http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
<span style="color:#ff0000;">http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd"</span>>

然后需要导入的包有几个：

1. aspectjrt.jar

2. aspectjweaver.jar

3. aopalliance-1.0.jar

我在使用的时候由于没有使用第三个jar包导致了异常信息如下：

警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.config.internalAutoProxyCreator': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.config.internalAutoProxyCreator': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1050)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:228)
	at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:687)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:523)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at com.siti.spring20160315aop.MainTest.main(MainTest.java:9)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098)
	... 13 more

下面开始使用AspectJ进行切面配置

AspectJ注解方式进行切面配置

定义四个接口，下面让WangYang类实现这个Person的接口，并实现其中的方法。

package com.siti.spring20160315aop;

public interface Person {

	void say();
	void sayName(String name);
	String saySth(String name);
	void sayEx();
}

其中saySth这个方法设置了返回值，这个地方会被AfterReturning织入，然后sayEx方法为了测试故意利用空指针异常，测试AfterThrowing会不会被织入。

package com.siti.spring20160315aop;

public class WangYang implements Person{

	@Override
	public void say() {
		System.out.println("wy!");
	}

	@Override
	public void sayName(String name) {
		System.out.println("name-->" + name);
	}

	@Override
	public String saySth(String name) {
		System.out.println("name-->" + name);
		return name;
	}

	@Override
	public void sayEx() {
		Object obj = null;
		obj.equals("1");
	}
}

面向切面编程AspectJ的实现，主要方式如下，其中，after通知主要用于释放资源，afterReturning通知可以对返回值进行更改，afterThrowing通知可以进行异常捕获生成异常记录，before这个通知可以进行参数的校验之类的。

package com.siti.spring20160315aop;

import java.util.Arrays;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;

@Aspect
public class MyInterceptor {

	@Pointcut("execution(* com.siti.spring20160315aop.WangYang.*(..))")
	public void anyMethod(){}
	
	@Before("anyMethod()")
	public void checkMessage(JoinPoint joinPoint){
		System.out.println("@Before-check!!!");
		System.out.println("@Before-目标对象为：" + joinPoint.getTarget());
		System.out.println("@Before-目标方法：" + joinPoint.getSignature().getName());
		System.out.println("@Before-目标方法的参数：" + Arrays.toString(joinPoint.getArgs()));
	}
	
	@AfterReturning(pointcut = "anyMethod()", returning = "obj")
	public void checkReturn(JoinPoint joinPoint, Object obj){
		System.out.println("@AfterReturning-目标方法返回值：" + obj);
		System.out.println("@AfterReturning-生成日志");
		
		System.out.println("@AfterReturning-目标对象为：" + joinPoint.getTarget());
		System.out.println("@AfterReturning-目标方法：" + joinPoint.getSignature().getName());
		System.out.println("@AfterReturning-目标方法的参数：" + Arrays.toString(joinPoint.getArgs()));
	}
	
	@After("anyMethod()")
	public void checkAfter(JoinPoint joinPoint){
		System.out.println("@After-释放资源！");
		
		System.out.println("@After-目标对象为：" + joinPoint.getTarget());
		System.out.println("@After-目标方法：" + joinPoint.getSignature().getName());
		System.out.println("@After-目标方法的参数：" + Arrays.toString(joinPoint.getArgs()));
	}
	
	@Around("anyMethod()")
	public Object checkAround(ProceedingJoinPoint joinPoint) throws Throwable{
		System.out.println("@Around！");
		
		Object[] args = joinPoint.getArgs();
		if(args != null && args.length > 0 && args[0].getClass() == String.class){
			args[0] = "@Around" + args[0];
		}
		Object result = joinPoint.proceed(args);
		if(result != null && result.getClass() == String.class){
			result = result + "--wy";
		}
		return result;
	}
	
	@AfterThrowing(throwing = "ex", pointcut = "anyMethod()")
	public void checkAfterThrowing(Throwable ex){
		System.out.println("@AfterThrowing-异常抛出！");
		System.out.println("@AfterThrowing-异常日志！");
		
	}
	
	
}

配置文件需要将我们自己写的这个切面的类，在配置文件中进行“注册”。

<?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"
       xsi:schemaLocation="
http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd">
	<aop:aspectj-autoproxy/>
	
	<bean id = "inter" class = "com.siti.spring20160315aop.MyInterceptor"></bean>
	<bean id = "wy" class = "com.siti.spring20160315aop.WangYang"></bean>
</beans>

测试：

package com.siti.spring20160315aop;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainTest {

	public static void main(String[] args) {
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext20160315.xml");
		Person wy = context.getBean("wy", Person.class);
		wy.say();
		wy.sayName("wangyang-");
		String str = wy.saySth("hello--");
		System.out.println("str的值：" + str);
		// wy.sayEx();// 抛出异常的测试
	}
}

XML配置文件的方式

基于配置文件配置的方式和前面的注解的方式基本上类似的，这里只是将，改动的地方列出来，不做介绍了。

配置文件如下：

<?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"
       xsi:schemaLocation="
http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd">
	
	<aop:config>
		<!-- 定义公共的切入点表达式 -->
		<aop:pointcut expression="execution(* com.siti.spring20160315aopwithxml.WangYang.*(..))" id="pointCutCommon"/>
		<!-- 定义切面，命名为 adviceRespect 优先级是2 ref：表示对谁进行增强处理-->
		<aop:aspect id = "adviceRespect" ref = "inter" order="2">
			<aop:before pointcut-ref="pointCutCommon" method="checkMessage"/>
			<aop:after-returning pointcut-ref="pointCutCommon" method="checkReturn" returning="obj"/>
			<aop:around pointcut-ref="pointCutCommon" method="checkAround"/>
			<aop:after pointcut-ref="pointCutCommon" method="checkAfter"/>
		</aop:aspect>
		<aop:aspect id = "firstExecute" ref = "inter" order = "1">
			<aop:after-throwing pointcut-ref="pointCutCommon" method="checkAfterThrowing" throwing="ex"/>
		</aop:aspect>	
	</aop:config>
	<bean id = "inter" class = "com.siti.spring20160315aopwithxml.MyInterceptor"></bean>
	<bean id = "wy" class = "com.siti.spring20160315aopwithxml.WangYang"></bean>
</beans>

package com.siti.spring20160315aopwithxml;

import java.util.Arrays;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;

public class MyInterceptor {

	public void anyMethod(){}
	
	public void checkMessage(JoinPoint joinPoint){
		System.out.println("@Before-check!!!");
		System.out.println("@Before-目标对象为：" + joinPoint.getTarget());
		System.out.println("@Before-目标方法：" + joinPoint.getSignature().getName());
		System.out.println("@Before-目标方法的参数：" + Arrays.toString(joinPoint.getArgs()));
	}
	
	public void checkReturn(JoinPoint joinPoint, Object obj){
		System.out.println("@AfterReturning-目标方法返回值：" + obj);
		System.out.println("@AfterReturning-生成日志");
		
		System.out.println("@AfterReturning-目标对象为：" + joinPoint.getTarget());
		System.out.println("@AfterReturning-目标方法：" + joinPoint.getSignature().getName());
		System.out.println("@AfterReturning-目标方法的参数：" + Arrays.toString(joinPoint.getArgs()));
	}
	
	public void checkAfter(JoinPoint joinPoint){
		System.out.println("@After-释放资源！");
		
		System.out.println("@After-目标对象为：" + joinPoint.getTarget());
		System.out.println("@After-目标方法：" + joinPoint.getSignature().getName());
		System.out.println("@After-目标方法的参数：" + Arrays.toString(joinPoint.getArgs()));
	}
	
	public Object checkAround(ProceedingJoinPoint joinPoint) throws Throwable{
		System.out.println("@Around！");
		
		Object[] args = joinPoint.getArgs();
		if(args != null && args.length > 0 && args[0].getClass() == String.class){
			args[0] = "@Around" + args[0];
		}
		Object result = joinPoint.proceed(args);
		if(result != null && result.getClass() == String.class){
			result = result + "--wy";
		}
		return result;
	}
	
	public void checkAfterThrowing(Throwable ex){
		System.out.println("@AfterThrowing-异常抛出！");
		System.out.println("@AfterThrowing-异常日志！");
		
	}
	
}

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