在spring中使用bytebuddy 对bean做Aop拦截

背景

拦截spring 中的某个bean拦截其方法的调用。在其前后做一些类似于aop的操作

拦截bean

MyBeanDefinitionRegistryPostProcessor

java">import lombok.extern.slf4j.Slf4j;
import net.bytebuddy.ByteBuddy;
import net.bytebuddy.asm.Advice;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;import static net.bytebuddy.matcher.ElementMatchers.named;
import static net.bytebuddy.matcher.ElementMatchers.returns;/*** @author wxl*/
@Slf4j
public class MyBeanDefinitionRegistryPostProcessor implements BeanDefinitionRegistryPostProcessor {@Overridepublic void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {boolean userService = registry.containsBeanDefinition("userService");if (userService) {registry.removeBeanDefinition("userService");Class<? extends UserService> method02 = new ByteBuddy().subclass(UserService.class).method(named("method02").and(returns(String.class))).intercept(Advice.to(LoggerAdvisor.class)).make().load(getClass().getClassLoader()).getLoaded();BeanDefinition beanDefinitions = BeanDefinitionBuilder.rootBeanDefinition(method02).getBeanDefinition();beanDefinitions.setAutowireCandidate(true);registry.registerBeanDefinition("userService", beanDefinitions);}}}

LoggerAdvisor

java">import lombok.extern.slf4j.Slf4j;
import net.bytebuddy.asm.Advice;import java.lang.reflect.Method;
import java.util.Arrays;/*** @author wxl*/
@Slf4j
public class LoggerAdvisor {@Advice.OnMethodEnterpublic static void onMethodEnter(@Advice.Origin Method method, @Advice.AllArguments Object[] arguments) {System.out.println("Enter " + method.getName() + " with arguments: " + Arrays.toString(arguments));}@Advice.OnMethodExitpublic static void onMethodExit(@Advice.Origin Method method, @Advice.AllArguments Object[] arguments, @Advice.Return Object ret) {System.out.println("Exit " + method.getName() + " with arguments: " + Arrays.toString(arguments) + " return: " + ret);}
}

BeanB

java">
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;/*** @author wxl*/
@Component
public class BeanB {@Autowiredprivate UserService userService;public void test() {System.out.println("beanB");userService.method02("ss");}
}

测试

java">import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;/*** @author wxl*/
@Slf4j
@SpringBootApplication
public class SpringBytecodeDemoApplication {public static void main(String[] args) throws Exception {
//        ClassPool pool = ClassPool.getDefault();
//        CtClass cc = pool.get("cc.sofast.demo.springbytecodedemo.UserService");
//        cc.defrost();
//        CtMethod m = cc.getDeclaredMethod("say");
//        m.insertBefore("{ System.out.println(\"Hello.say():\"); }");
//        m.insertAfter("{ System.out.println(\"result: \"+$_); }");
//        cc.writeFile(".");
//        cc.toClass();
//        ByteBuddyAgent.install();
//
//        new ByteBuddy()
//                .redefine(UserService.class)
//                .method(named("method02").and(returns(String.class)))
//                .intercept(to(new OvUserService()))
//                .make()
//                .load(UserService.class.getClassLoader(), ClassReloadingStrategy.fromInstalledAgent());ConfigurableApplicationContext context = SpringApplication.run(SpringBytecodeDemoApplication.class, args);BeanB bean = context.getBean(BeanB.class);bean.test();}@Beanpublic MyBeanDefinitionRegistryPostProcessor myBeanDefinitionRegistryPostProcessor() {return new MyBeanDefinitionRegistryPostProcessor();}}

build.gradle

    implementation 'org.javassist:javassist:3.30.2-GA'implementation 'net.bytebuddy:byte-buddy:1.14.14'implementation 'net.bytebuddy:byte-buddy-agent:1.14.14'