spring注解AOP报错：警告: Exception encountered during context initialization - cancelling refresh attempt

今天在学习spring框架时，使用到了注解方式的AOP，当运行程序时，程序报错如下

警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'accountService' defined in file [F:\Program Files\JetBrains\spring\day03_05_annotation_AOP\target\classes\com\example\service\impl\AccountServiceImpl.class]: BeanPostProcessor before instantiation of bean failed; nested exception is java.lang.IllegalArgumentException: @org.aspectj.lang.annotation.AfterReturning(pointcut="", value="", argNames="", returning="") is not a valid AspectJ annotation
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'accountService' defined in file [F:\Program Files\JetBrains\spring\day03_05_annotation_AOP\target\classes\com\example\service\impl\AccountServiceImpl.class]: BeanPostProcessor before instantiation of bean failed; nested exception is java.lang.IllegalArgumentException: @org.aspectj.lang.annotation.AfterReturning(pointcut="", value="", argNames="", returning="") is not a valid AspectJ annotation
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:512)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:895)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
	at com.example.AOPTest.main(AOPTest.java:16)
Caused by: java.lang.IllegalArgumentException: @org.aspectj.lang.annotation.AfterReturning(pointcut="", value="", argNames="", returning="") is not a valid AspectJ annotation
	at org.springframework.aop.aspectj.annotation.AbstractAspectJAdvisorFactory$AspectJAnnotation.<init>(AbstractAspectJAdvisorFactory.java:201)
	at org.springframework.aop.aspectj.annotation.AbstractAspectJAdvisorFactory.findAnnotation(AbstractAspectJAdvisorFactory.java:146)
	at org.springframework.aop.aspectj.annotation.AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(AbstractAspectJAdvisorFactory.java:134)
	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory.lambda$static$0(ReflectiveAspectJAdvisorFactory.java:80)
	at org.springframework.core.convert.converter.ConvertingComparator.compare(ConvertingComparator.java:79)
	at java.base/java.util.Comparator.lambda$thenComparing$36697e65$1(Comparator.java:216)
	at java.base/java.util.TimSort.countRunAndMakeAscending(TimSort.java:355)
	at java.base/java.util.TimSort.sort(TimSort.java:220)
	at java.base/java.util.Arrays.sort(Arrays.java:1515)
	at java.base/java.util.ArrayList.sort(ArrayList.java:1749)
	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory.getAdvisorMethods(ReflectiveAspectJAdvisorFactory.java:158)
	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory.getAdvisors(ReflectiveAspectJAdvisorFactory.java:125)
	at org.springframework.aop.aspectj.annotation.BeanFactoryAspectJAdvisorsBuilder.buildAspectJAdvisors(BeanFactoryAspectJAdvisorsBuilder.java:110)
	at org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator.findCandidateAdvisors(AnnotationAwareAspectJAutoProxyCreator.java:95)
	at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.shouldSkip(AspectJAwareAdvisorAutoProxyCreator.java:101)
	at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessBeforeInstantiation(AbstractAutoProxyCreator.java:251)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:1141)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:1114)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:506)
	... 10 more
Caused by: java.lang.IllegalStateException: Failed to resolve expression: @org.aspectj.lang.annotation.AfterReturning(pointcut="", value="", argNames="", returning="")
	at org.springframework.aop.aspectj.annotation.AbstractAspectJAdvisorFactory$AspectJAnnotation.resolveExpression(AbstractAspectJAdvisorFactory.java:223)
	at org.springframework.aop.aspectj.annotation.AbstractAspectJAdvisorFactory$AspectJAnnotation.<init>(AbstractAspectJAdvisorFactory.java:196)
	... 28 more
Disconnected from the target VM, address: '127.0.0.1:56177', transport: 'socket'

Process finished with exit code 1

发现错误中有这句话

Error creating bean with name 'accountService' defined in file [F:\Program Files\JetBrains\spring\day03_05_annotation_AOP\target\classes\com\example\service\impl\AccountServiceImpl.class]: 
BeanPostProcessor before instantiation of bean failed; nested exception is java.lang.IllegalArgumentException: 
@org.aspectj.lang.annotation.AfterReturning(pointcut="", value="", argNames="", returning="") is not a valid AspectJ annotation

然后确定问题出在AfterReturning这个注解这里

结果发现是因为没有为其设置切入点表达式

原来的代码是这样的

@Component("logger")
@Aspect//当前类是一个切面类
public class Logger {

    @Pointcut("execution(* com.example.service.impl.*.*(..))")
    private void pointcut1() {}

    /**
     * 前置通知
     */
    @Before("pointcut1()")
    public void beforePrintLog() {
        System.out.println("前置通知 类的 beforePrintLog 方法执行了......");
    }

    /**
     * 后置通知
     */
    @AfterReturning
    public void afterReturningPrintLog() {
        System.out.println("后置通知 类的 afterReturningPrintLog 方法执行了......");
    }
}

注意，后置通知那里的注解没有加上切入点表达式（代码中的pointcut1()）

所以只需要像@Before那样加上切入点表达式就可以了！

@Component("logger")
@Aspect//当前类是一个切面类
public class Logger {

    @Pointcut("execution(* com.example.service.impl.*.*(..))")
    private void pointcut1() {}

    /**
     * 前置通知
     */
    @Before("pointcut1()")
    public void beforePrintLog() {
        System.out.println("前置通知 类的 beforePrintLog 方法执行了......");
    }

    /**
     * 后置通知
     */
    @AfterReturning("pointcut1()")
    public void afterReturningPrintLog() {
        System.out.println("后置通知 类的 afterReturningPrintLog 方法执行了......");
    }
}