java - 检测 Spring Boot 应用程序时的类路径问题

Question

我有一个 springboot 应用程序，我正在尝试使用 bytebuddy 进行检测。我遇到了无法理解的类路径问题。

首先，以下是关于此的其他文献:

https://github.com/raphw/byte-buddy/issues/473

https://github.com/raphw/byte-buddy/issues/87

Unable to instrument apache httpclient using javaagent for spring boot uber jar application

https://github.com/raphw/byte-buddy/issues/109

https://github.com/raphw/byte-buddy/issues/473

https://github.com/raphw/byte-buddy/issues/489

https://github.com/spring-projects/spring-boot/issues/4868

https://github.com/alibaba/transmittable-thread-local/issues/161

问题是 Spring-boot 将应用程序捆绑到一个 uber-jar 中，其中包含其他 jars



这里要注意的一点是，如果我使用 IntelliJ 运行应用程序，它不使用 uber-jar 并通过主类运行，并使用一堆 jar 作为类路径参数。

由于这种差异，当通过 uber-jar( java -jar target/demo-0.0.1-SNAPSHOT.jar ) 运行时，代理运行时某些类不可用。这些类在 application main 时是可加载的，因为 spring-boot 使用它自己的 classloader，它在某个时间创建 b/w agent 和 application main 方法。

我将在下面描述不同时间点的行为:

Agent的PreMain时间

Thread.currentThread().getContextClassLoader() = Launcher$AppClassLoader

Agent.class.classLoader = Launcher$AppClassLoader

Class.forName("org.springframework.web.servlet.HandlerAdapter") => ClassNotFoundException

Class.forName("javax.servlet.http.HttpServletRequest") => ClassNotFoundException

spring 和 javax 类都未加载，因为它们不直接位于 App Classloader 的类路径中。它是内 jar 的一部分，类似于 app.jar!/BOOT-INF/lib/some.jar应用类加载器将无法加载它。

申请类的主要时

Thread.currentThread().getContextClassLoader() = org.springframework.boot.loader.LaunchedURLClassLoader

DemoApplication.class.classloader = same as above

Class.forName("org.springframework.web.servlet.HandlerAdapter") => loads successfully

javax 类相同，加载成功。

加载后， Class.forName("javax.servlet.http.HttpServletRequest").classLoader也是一样 LaunchedURLClassLoader .

时 builder.visit调用(当 bytebuddy 正在修改类定义时)

代码:

我有两个类(class)， SpringBootInterceptor (其中包含拦截方法)和 SpringBootInterceptorOne (其中包含进入和退出方法)

  @Override
  public AgentBuilder intercept(AgentBuilder agentBuilder) {
    return agentBuilder
      .type(isSubTypeOf(HandlerAdapter.class))
      .transform((builder, typeDescription, classLoader, module) ->
        builder.visit(Advice.to(SpringBootInterceptorOne.class, SpringBootInterceptorOne.class).on(named("handle").and(isMethod())))
      );
  }

函数 intercept()在 premain 路径中调用。

函数 visit在实际尝试加载类型时调用。此时，bytebuddy 会尝试拦截这些方法并修改字节码。

在此代码的当前版本中，函数 intercept()抛出 ClassNotFoundException并且拦截不会发生。

Caused by: java.lang.NoClassDefFoundError: org/springframework/web/servlet/HandlerAdapter

因此，我尝试将代码更改为以下内容:

  @Override
  public AgentBuilder intercept(AgentBuilder agentBuilder) {
    return agentBuilder
//      .type(isSubTypeOf(HandlerAdapter.class))
      .type(not(isInterface())
        .and(safeHasSuperType(named("org.springframework.web.servlet.HandlerAdapter"))))
      .transform((builder, typeDescription, classLoader, module) ->
        builder.visit(Advice.to(SpringBootInterceptorOne.class, SpringBootInterceptorOne.class).on(named("handle").and(isMethod())))
      );
  }

在这里，基本上是懒惰地加载类。
来自 datadog 的辅助函数:

https://github.com/DataDog/dd-trace-java/blob/master/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/ByteBuddyElementMatchers.java

这样做后， intercept功能不会失败，但 visit()函数的行为很奇怪:

java.lang.IllegalStateException: Could not locate class file for my.package.name.SpringBootInterceptorOne
    at net.bytebuddy.dynamic.ClassFileLocator$Resolution$Illegal.resolve(ClassFileLocator.java:118)
    at net.bytebuddy.asm.Advice.to(Advice.java:431)
    at net.bytebuddy.asm.Advice.to(Advice.java:400)
    at net.bytebuddy.asm.Advice.to(Advice.java:375)
    at net.bytebuddy.asm.Advice.to(Advice.java:361)
    at my.package.name.SpringBootInterceptor.lambda$intercept$0(SpringBootInterceptor.java:30)
    at net.bytebuddy.agent.builder.AgentBuilder$Transformer$Compound.transform(AgentBuilder.java:2612)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$Transformation$Simple$Resolution.apply(AgentBuilder.java:10117)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$ExecutingTransformer.doTransform(AgentBuilder.java:10494)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$ExecutingTransformer.transform(AgentBuilder.java:10457)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$ExecutingTransformer.access$1500(AgentBuilder.java:10223)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$ExecutingTransformer$LegacyVmDispatcher.run(AgentBuilder.java:10833)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$ExecutingTransformer$LegacyVmDispatcher.run(AgentBuilder.java:10780)
    at java.security.AccessController.doPrivileged(Native Method)
    at net.bytebuddy.agent.builder.AgentBuilder$Default$ExecutingTransformer.transform(AgentBuilder.java:10380)
    at sun.instrument.TransformerManager.transform(TransformerManager.java:188)
    at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:428)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:757)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
    at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:92)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.getDeclaredMethods(Class.java:1975)
    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:463)
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:358)
    at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:414)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.lambda$getTypeForFactoryMethod$2(AbstractAutowireCapableBeanFactory.java:743)
    at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1688)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:742)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:681)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:649)
    at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1604)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:520)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:491)
    at org.springframework.boot.autoconfigure.condition.OnBeanCondition.collectBeanNamesForType(OnBeanCondition.java:230)
    at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getBeanNamesForType(OnBeanCondition.java:223)
    at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getBeanNamesForType(OnBeanCondition.java:213)
    at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getMatchingBeans(OnBeanCondition.java:167)
    at org.springframework.boot.autoconfigure.condition.OnBeanCondition.getMatchOutcome(OnBeanCondition.java:142)
    at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:47)
    at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:108)
    at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(ConfigurationClassBeanDefinitionReader.java:184)
    at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:144)
    at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:120)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:331)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:236)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:706)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
    at com.example.demo.DemoApplication.main(DemoApplication.java:10)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:51)
    at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:52)

这一点，

Thread.currentThread().getContextClassLoader() => LaunchedURLClassLoader

SpringBootInterceptor.class.getClassLoader() = null

打字 SpringBootInterceptor.class在调试器窗口中没有失败，但

Class.forName("my.package.name.SpringBootInterceptorOne") => NoClassDefFound

接下来，我尝试了以下操作:

  @Override
  public AgentBuilder intercept(AgentBuilder agentBuilder) {
    ClassLoader cl = Thread.currentThread().getContextClassLoader();
    return agentBuilder
//      .type(isSubTypeOf(HandlerAdapter.class))
      .type(not(isInterface())
        .and(safeHasSuperType(named("org.springframework.web.servlet.HandlerAdapter"))))
      .transform((builder, typeDescription, classLoader, module) -> {
          try {
            Class<?> claz = Thread.currentThread().getContextClassLoader().loadClass("my.package.name.SpringBootInterceptorOne");
            return builder.visit(Advice.to(claz, claz,
              new ClassFileLocator.Compound(ClassFileLocator.ForClassLoader.of(cl),
              ClassFileLocator.ForClassLoader.of(Thread.currentThread().getContextClassLoader())
              )).on(named("handle").and(isMethod())));
          } catch (ClassNotFoundException e) {
            e.printStackTrace();
            return builder;
          }
        }
      );
  }

这会导致拦截器被“安装”。进入和退出方法称为okay。但是将参数转换为正确的类型会给参数的类型带来错误

exit spring boot
[Ljava.lang.Object;@c83066a
java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
    at my.package.name.SpringBootInterceptorOne.getEndpoint(SpringBootInterceptorOne.java:36)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1598)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

这里是 SpringBootInterceptorOne 供引用:

  @Advice.OnMethodExit
  static void exit(@Advice.Origin final Executable executable,
                   @Advice.This Object handlerAdapter,
                   @Advice.AllArguments Object[] arguments,
                   @Advice.Enter final TimerContext ctx) {
//      final long duration = ctx.getDuration();
    System.out.println("exit spring boot");
    String e = getEndpoint(arguments);
    System.out.println(e);
  }

  public static String getEndpoint(Object[] arguments) {
    System.out.println(arguments);
    HttpServletRequest request = (HttpServletRequest) arguments[0];
    HandlerMethod  handler = (HandlerMethod) arguments[2];
    return "ad";
  }

更新:

根据答案中提供的建议，我尝试了以下操作:

  @Override
  public AgentBuilder intercept(AgentBuilder agentBuilder) {
    return agentBuilder
//      .type(isSubTypeOf(HandlerAdapter.class))
      .type(not(isInterface())
        .and(safeHasSuperType(named("org.springframework.web.servlet.HandlerAdapter"))))
      .transform(new AgentBuilder.Transformer.ForAdvice()
        .include(SpringBootInterceptorOne.class.getClassLoader())
        .include(getClass().getClassLoader())
        .advice(named("handle"), SpringBootInterceptorOne.class.getName())
      );
  }

它再次抛出错误:

java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
    at io.signoz.interceptors.http.server.springboot.SpringBootInterceptorOne.getEndpoint(SpringBootInterceptorOne.java:37) ~[na:na]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1598) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_242]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_242]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.30.jar!/:9.0.30]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_242]

Answer 1

问题是建议类将作为代理的一部分加载到系统类加载器上，而实际应用程序代码加载到系统类加载器不可见的子类加载器上。如果您在引导加载程序上加载代理，这种情况也不会改变。因此，代理无法加载 HttpServletRequest属于 uber-jar 的类。

这是代理的典型问题，Byte Buddy 有一种标准方法可以通过使用 Transformer.ForAdvice 来规避它。实例而不是使用 Advice直接上课。 Byte Buddy 然后创建一个虚拟类加载器层次结构，该层次结构考虑由两个类加载器表示的类。

更新 :问题是您正在调用系统类加载器中定义的拦截器，其中相关类不可用。带注释的代码将被内联，但调用的方法不会。如果您将代码复制粘贴到带注释的方法中，则行为与您期望的一样。 Byte Buddy 使用带注释的代码作为模板，并重用 javac 发出的大量信息来保证快速转换。因此，库不能简单地复制方法，而应该将整个方法体提供给 javac。