java Byte Buddy的方法委派导致StackOverflower错误

Question

我试图创建一个代理来代理这些方法，以便在方法之前和之后执行一些逻辑。为了做到这一点，我使用Byte Buddy和方法委派

代理人：

//Agent code before...
private static void instrument(String agentOps, Instrumentation inst) {
    new AgentBuilder.Default().with(new Eager())
            .ignore(ElementMatchers.nameContains("com.dvelopp.agenttest"))
            .or(ElementMatchers.hasAnnotation(ElementMatchers.annotationType(ElementMatchers.nameContains("SpringBootApplication"))))
            .type((ElementMatchers.any()))
            .transform((builder, typeDescription, classLoader, module) -> builder.method(ElementMatchers.any())
                    .intercept(MethodDelegation.to(Interceptor.class)))
            .installOn(inst);
}
//Agent code after...

拦截器：

public static class Interceptor {

    @RuntimeType
    public static Object intercept(@SuperCall Callable<?> superCall, @SuperMethod Method superMethod, @Origin Method currentMethod,
                                   @AllArguments Object[] args, @This(optional = true) Object me) throws Exception {
        //... logic
        Object call = superCall.call();
        //... logic
        return call;
    }
}

它在一个简单的控制台应用程序上运行得非常完美。但是，当我的类路径中有一些公共库（例如简单的Spring Boot项目）时，它并没有像预期的那样工作。它会产生不同的错误，但大多数错误都与以下意外反射有关：

Exception in thread "main" java.lang.NoClassDefFoundError: sun/reflect/GeneratedMethodAccessor24
at sun.reflect.GeneratedMethodAccessor24.<clinit>(Unknown Source)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:403)
at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:394)
at java.security.AccessController.doPrivileged(Native Method)
at sun.reflect.MethodAccessorGenerator.generate(MethodAccessorGenerator.java:393)
at sun.reflect.MethodAccessorGenerator.generateMethod(MethodAccessorGenerator.java:75)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:53)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.logging.log4j.status.StatusLogger.<clinit>(StatusLogger.java:85)
at org.apache.logging.log4j.LogManager.<clinit>(LogManager.java:60)
at org.apache.commons.logging.LogAdapter$Log4jLog.<clinit>(LogAdapter.java:135)
at org.apache.commons.logging.LogAdapter$Log4jAdapter.createLog$original$snrPR67N(LogAdapter.java:102)
at org.apache.commons.logging.LogAdapter$Log4jAdapter.createLog$original$snrPR67N$accessor$5P1QZaof(LogAdapter.java)
at org.apache.commons.logging.LogAdapter$Log4jAdapter$auxiliary$pVmPc64S.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:126)
at org.apache.commons.logging.LogAdapter$Log4jAdapter.createLog(LogAdapter.java)
at org.apache.commons.logging.LogAdapter.createLog$original$4Ty3vM8s(LogAdapter.java:79)
at org.apache.commons.logging.LogAdapter.createLog$original$4Ty3vM8s$accessor$z3gv7aJK(LogAdapter.java)
at org.apache.commons.logging.LogAdapter$auxiliary$6cBoraQE.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:126)
at org.apache.commons.logging.LogAdapter.createLog(LogAdapter.java)
at org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7(LogFactory.java:67)
at org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7$accessor$VdtqA6Wx(LogFactory.java)
at org.apache.commons.logging.LogFactory$auxiliary$ak9XEBl0.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:126)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java)
at org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7(LogFactory.java:59)
at org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7$accessor$VdtqA6Wx(LogFactory.java)
at org.apache.commons.logging.LogFactory$auxiliary$8JhBdK8k.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:126)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java)
at org.springframework.boot.SpringApplication.<clinit>(SpringApplication.java:194)
at hello.Application.main(Application.java:15)
Caused by: java.lang.ClassNotFoundException: sun.reflect.GeneratedMethodAccessor24
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 39 more

正如我所见，这些错误发生在代理对象上：

e.g. org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7

我试着进行更深入的调试，发现super method和origin有不同的类。“超级”有一个代理类

@SuperMethod Method superMethod, @Origin Method currentMethod

有没有一种方法可以让委派与这些对象一起工作

补充：

在这个Spring Boot 2示例（https://spring.io/guides/gs/spring-boot/）中，有一个明确的StackOverflower错误：

java.lang.StackOverflowError: null
at com.dvelopp.agenttest.MethodCallContext.getCaller(MethodCallContext.java:18)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:108)
at org.springframework.core.env.SystemEnvironmentPropertySource.getSource(SystemEnvironmentPropertySource.java)
at org.springframework.core.env.MapPropertySource.getSource(MapPropertySource.java)
at org.springframework.core.env.SystemEnvironmentPropertySource.getSource$accessor$d92Pg8OK(SystemEnvironmentPropertySource.java)
at org.springframework.core.env.SystemEnvironmentPropertySource$auxiliary$ATPz5tSr.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:122)
at org.springframework.core.env.SystemEnvironmentPropertySource.getSource(SystemEnvironmentPropertySource.java)
at org.springframework.core.env.MapPropertySource.getSource(MapPropertySource.java)
at org.springframework.core.env.SystemEnvironmentPropertySource.getSource$accessor$d92Pg8OK(SystemEnvironmentPropertySource.java)
at org.springframework.core.env.SystemEnvironmentPropertySource$auxiliary$ATPz5tSr.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:122)
at org.springframework.core.env.SystemEnvironmentPropertySource.getSource(SystemEnvironmentPropertySource.java)
at org.springframework.core.env.MapPropertySource.getSource(MapPropertySource.java)
at org.springframework.core.env.SystemEnvironmentPropertySource.getSource$accessor$d92Pg8OK(SystemEnvironmentPropertySource.java)
at org.springframework.core.env.SystemEnvironmentPropertySource$auxiliary$ATPz5tSr.call(Unknown Source)
at com.dvelopp.agenttest.Main$Interceptor.intercept(Main.java:122)

Answer 1

似乎您使用了错误的注释或功能

我建议检查更简单的情况。例如，替换您的实现：

    @RuntimeType
    public static Object intercept(@SuperCall Callable<?> superCall, @SuperMethod Method superMethod, @Origin Method currentMethod,
                                   @AllArguments Object[] args, @This(optional = true) Object me) throws Exception {
        return superCall.call();
    }

下一个：

    @RuntimeType
    public static Object intercept(@RuntimeType Object value) throws Exception {
        return value;
    }

在这种情况下，您避免了递归调用，但可能会有机会检测和分析不同的问题，这是明确的，并与您的情况有关

可能你也应该注意概念问题。你知道java使用Callable对象的开发者不应该直接使用call()

下面是它用于从一个对象映射到另一个对象的@RuntimeType的API描述。出现了一个新问题：为什么需要转换callable对象？它将被转换为哪种类型（你确定如果没有未来的包装器，你会有一个对象。可能会有null导致你的异常，不是吗？）