Spring-AOP源码探究

动态代理
aop
spring动态增强插件
- 背景与需求

# 动态代理

java自带的动态代理

public class JavaProxyTest {

    public static void main(String[] args) {

        Cat cat = new Cat();
        Animal animal = (Animal) Proxy.newProxyInstance(JavaProxyTest.class.getClassLoader(), new Class[]{Animal.class}, new InvocationHandler() {
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                System.out.println("前置");
                try {
                    Object o = method.invoke(cat,args);
                    System.out.println("后置");
                    return o;
                }catch (Exception e){
                    System.out.println("异常通知");
                }
                return null;
            }
        });
        System.out.println(animal.getName());
    }
}

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源码主要在 Proxy类的静态类 ProxyClassFactory的apply方法

# aop

public class AopTest {


    @Test
    public void createProxyByAdvice(){
        Cat cat = new Cat();
        ProxyFactory proxyFactory = new ProxyFactory(cat);
        CountingBeforeAdvice beforeAdvice = new CountingBeforeAdvice();
        // advice: 拦截通知行为，所有的方法
        proxyFactory.addAdvice(beforeAdvice);

        Animal proxy = (Animal) proxyFactory.getProxy();
        proxy.getName();
    }

    @Test
    public void createProxyByAdvisor(){
        Cat cat = new Cat();
        ProxyFactory proxyFactory = new ProxyFactory(cat);

        // advice: 拦截通知行为
        CountingBeforeAdvice beforeAdvice = new CountingBeforeAdvice();
        // advisor: 连接点和通知的适配器
        Advisor advisor = new DefaultPointcutAdvisor(beforeAdvice);

        proxyFactory.addAdvisor(advisor);
        Animal proxy = (Animal) proxyFactory.getProxy();
        proxy.getName();
        assertThat(AopUtils.isJdkDynamicProxy(proxy)).as("Proxy is a JDK proxy").isTrue();
        System.out.println(proxy);
    }

    @Test
    public void createProxyByAspectJ(){
        Cat cat = new Cat();
        ProxyFactory proxyFactory = new ProxyFactory(cat);

        // advice: 拦截通知行为
        CountingBeforeAdvice beforeAdvice = new CountingBeforeAdvice();
        // advisor: 连接点和通知的适配器
        AspectJExpressionPointcutAdvisor advisor = new AspectJExpressionPointcutAdvisor();
        advisor.setAdvice(beforeAdvice);
        advisor.setExpression("execution(* *.getName(..))");

        // advice: 切面
        proxyFactory.addAdvisor(advisor);

        Animal proxy = (Animal) proxyFactory.getProxy();
        assertThat(AopUtils.isJdkDynamicProxy(proxy)).as("Proxy is a JDK proxy").isTrue();
        proxy.getName();
    }
}

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# Advice

拦截所有的通知方法

# Advisor

连接点和通知的适配器

# Adviced

包括advice和advisor

@Test
public void createProxyByAdvised(){
    Cat cat = new Cat();
    ProxyFactory proxyFactory = new ProxyFactory(cat);

    // advice: 拦截通知行为
    CountingBeforeAdvice beforeAdvice = new CountingBeforeAdvice();
    // advisor: 连接点和通知的适配器
    AspectJExpressionPointcutAdvisor advisor = new AspectJExpressionPointcutAdvisor();
    advisor.setAdvice(beforeAdvice);
    advisor.setExpression("execution(* *.getName(..))");

    Animal proxy = (Animal) proxyFactory.getProxy();
    Advised advised = (Advised) proxy;

    advised.addAdvisor(advisor);
    assertThat(AopUtils.isJdkDynamicProxy(proxy)).as("Proxy is a JDK proxy").isTrue();
    proxy.getName();
}

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# spring动态增强插件

# 背景与需求

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