说实话,由于我个人某些基础不是很牢固,所以前一段时间关于 Spring Aop 踩了一个坑,其实很简单,今天就记录一下,先说结论:

不能被 Spring AOP 增强的方法:

  1. 基于接口的动态代理:除 public 外的其它所有的方法,此外 public static 也不能被增强
  2. 基于 CGLib 的动态代理:private、static、final 的方法,也就是只有 public 和 protected 可以,但是要注意切入点语法的配置

测试用例如下,pom 文件:

<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-log4j12</artifactId>
  <version>1.7.7</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>4.3.11.RELEASE</version>
  <scope>test</scope>
</dependency>
<dependency>
  <groupId>org.aspectj</groupId>
  <artifactId>aspectjweaver</artifactId>
  <version>1.8.10</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>4.3.11.RELEASE</version>
</dependency>

配置文件就比较简单了:

<?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:context="http://www.springframework.org/schema/context"
  xmlns:aop="http://www.springframework.org/schema/aop"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
  http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
  http://www.springframework.org/schema/context
  http://www.springframework.org/schema/context/spring-context-2.5.xsd
  http://www.springframework.org/schema/aop
  http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
  <context:annotation-config/>
  <context:component-scan base-package="cn.bridgeli"/>
  <aop:aspectj-autoproxy/>

</beans>

切面类:

package cn.bridgeli.demo.aop;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LogInterceptor {
  // @Pointcut("execution(* * com.bjsxt.service..*.add(..))")
  @Pointcut("execution(* cn.bridgeli.demo.service..*.*(..))")
  public void myMethod() {
  }

  @Before("myMethod()")
  public void before() {
    System.out.println("method before");
  }

  @Around("myMethod()")
  public void aroundMethod(ProceedingJoinPoint pjp) throws Throwable {
    System.out.println("method around start");
    pjp.proceed();
    System.out.println("method around end");
  }
}

测试类:

package cn.bridgeli.demo.service;

import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Service;

@Service("userService")
public class UserService {

  /**
   * private方法因为修饰符访问权限的控制,无法被子类覆盖
   */
  void method1() {
    System.out.println("method1 executed");
  }

  /**
   * final 方法无法被子类覆盖
   */
  private final void method2() {
    System.out.println("method2 executed");
  }

  /**
   * static 方法是类级别的方法,无法被子类覆盖
   */
  private static void method3() {
    System.out.println("method3 executed");
  }

  /**
   * public 方法可以被子类覆盖,因此可以被动态字节码增强
   */
  public void method4() {
    System.out.println("method4 executed");
  }

  /**
   * final 方法无法被子类覆盖
   */
  public final void method5() {
    System.out.println("method5 executed");
  }

  /**
   * protected 方法可以被子类覆盖,因此可以被动态字节码增强
   */
  protected void method6() {
    System.out.println("method6 executed");
  }

  /**
   * 测试
   */
   /** @param args
   */
  public static void main(String[] args) {

    ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
    UserService userService = (UserService) ctx.getBean("userService");
    System.out.println("initContext successfully");

    System.out.println("before method1");
    userService.method1();
    System.out.println("after1 method1");

    System.out.println("before method2");
    userService.method2();
    System.out.println("after1 method2");

    System.out.println("before method3");
    method3();
    System.out.println("after1 method3");

    System.out.println("before method4");
    userService.method4();
    System.out.println("after1 method4");

    System.out.println("before method5");
    userService.method5();
    System.out.println("after1 method5");

    System.out.println("before method6");
    userService.method6();
    System.out.println("after1 method6");

    if (ctx != null) {
      ctx.close();
    }
    System.out.println("close context successfully");
  }
}

参考资料:

  1. http://jinnianshilongnian.iteye.com/blog/1857189
  2. https://blog.csdn.net/yangshangwei/article/details/78094196