AOP

原理

cglib

JDK Proxy实现。

Spring-AOP 简介

@see: https://www.baeldung.com/spring-aop

AspectJ 简介

@see: https://www.baeldung.com/aspectj

maven 依赖

    implementation 'org.springframework:spring-aop:5.2.0.RELEASE'         // <----- 似乎只支持XML

    // AOP
    // https://mvnrepository.com/artifact/org.aspectj/aspectjrt
    implementation group: 'org.aspectj', name: 'aspectjrt', version: '1.9.6'
    // https://mvnrepository.com/artifact/org.aspectj/aspectjweaver
    implementation group: 'org.aspectj', name: 'aspectjweaver', version: '1.9.6'

测试

package aop

import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Before
import org.junit.jupiter.api.Assertions.*
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.context.ApplicationContext
import org.springframework.context.annotation.ComponentScan
import org.springframework.context.annotation.EnableAspectJAutoProxy
import org.springframework.stereotype.Component
import org.springframework.test.context.junit.jupiter.SpringExtension
import org.springframework.test.context.junit.jupiter.SpringJUnitConfig

var isHandle = false

interface Foo {
    fun bar(): String = "Foo#bar()"
}

@Component
class MyFoo : Foo {
    override fun bar(): String {
        println("calling")
        return super.bar()
    }
}

@Component
@Aspect
@EnableAspectJAutoProxy
class MyAspect {
    @Before("execution(String bar())")
    fun handle() {
        println("handle called")
        isHandle = true
    }
}

@ComponentScan
class HeadfirstAOPJavaConfig

@ExtendWith(SpringExtension::class)
@SpringJUnitConfig(HeadfirstAOPJavaConfig::class)
class HeadfirstAOP {
    @Autowired lateinit var ctx: ApplicationContext

    @Autowired lateinit var foo: Foo

    @Test fun `handle() should be call`() {
        assertFalse(isHandle)
        val str = foo.bar()
        assertTrue(isHandle)
        println("str=$str")
    }
}

END