字节好友的方法委托导致StackOverflowError
Byte Buddy's method delegation leads to StackOverflowError
我正在尝试创建一个代理方法的代理，以便在方法前后执行一些逻辑。为此，我将 Byte Buddy 与方法委托结合使用。
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 class 路径中有一些常用库（例如简单的 Spring 引导项目）时，它无法按预期工作。它会产生不同的错误，但大多数都与这样的意外反射有关：
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.run(MethodAccessorGenerator.java:403)
at sun.reflect.MethodAccessorGenerator.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$snrPR67N$accessorP1QZaof(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$Log4jAdapter.createLog(LogAdapter.java)
at org.apache.commons.logging.LogAdapter.createLog$originalTy3vM8s(LogAdapter.java:79)
at org.apache.commons.logging.LogAdapter.createLog$originalTy3vM8s$accessor$z3gv7aJK(LogAdapter.java)
at org.apache.commons.logging.LogAdapter$auxiliarycBoraQE.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$auxiliaryJhBdK8k.call(Unknown Source)
at com.dvelopp.agenttest.Main$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$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 39 more
正如我所见，这些错误发生在作为代理的对象上：
e.g. org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7
我尝试进行更深入的调试，发现 super 方法和 origin 有不同的 classes。 "super" 有一个代理 class。
@SuperMethod Method superMethod, @Origin Method currentMethod
有没有办法让委托与这些对象一起工作？
已添加：
在这个 Spring Boot 2 示例 (https://spring.io/guides/gs/spring-boot/) 上有一个明确的 WhosebugError:
java.lang.WhosebugError: null
at com.dvelopp.agenttest.MethodCallContext.getCaller(MethodCallContext.java:18)
at com.dvelopp.agenttest.Main$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)
您似乎使用了错误的注释或功能。
我建议检查更简单的情况。例如替换你的实现：
@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();
}
与下一个：
@RuntimeType
public static Object intercept(@RuntimeType Object value) throws Exception {
return value;
}
在这种情况下你避免了递归调用，但可能会有机会检测和分析不同的问题，这很清楚并且与你的情况有关。
可能你也应该注意概念问题。你知道 java 使用 Callable 对象的开发人员不应该直接使用 call()。
按照 API 对 @RuntimeType 的描述，它用于从一个对象映射到另一个对象。出现新问题：为什么需要convert callable object？它将转换为哪种类型（你确定没有 Future 包装器你会有一个对象在那里。可能 null 可能导致你的异常，不是吗？）？
我正在尝试创建一个代理方法的代理，以便在方法前后执行一些逻辑。为此，我将 Byte Buddy 与方法委托结合使用。
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 class 路径中有一些常用库（例如简单的 Spring 引导项目）时，它无法按预期工作。它会产生不同的错误，但大多数都与这样的意外反射有关：
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.run(MethodAccessorGenerator.java:403)
at sun.reflect.MethodAccessorGenerator.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$accessorP1QZaof(LogAdapter.java)
at org.apache.commons.logging.LogAdapter$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$originalTy3vM8s(LogAdapter.java:79)
at org.apache.commons.logging.LogAdapter.createLog$originalTy3vM8s$accessor$z3gv7aJK(LogAdapter.java)
at org.apache.commons.logging.LogAdapter$auxiliarycBoraQE.call(Unknown Source)
at com.dvelopp.agenttest.Main$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$VdtqA6Wx(LogFactory.java)
at org.apache.commons.logging.LogFactory$auxiliaryJhBdK8k.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，这些错误发生在作为代理的对象上：
e.g. org.apache.commons.logging.LogFactory.getLog$original$MoDHp2B7
我尝试进行更深入的调试，发现 super 方法和 origin 有不同的 classes。 "super" 有一个代理 class。
@SuperMethod Method superMethod, @Origin Method currentMethod
有没有办法让委托与这些对象一起工作？
已添加：
在这个 Spring Boot 2 示例 (https://spring.io/guides/gs/spring-boot/) 上有一个明确的 WhosebugError:
java.lang.WhosebugError: 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)
您似乎使用了错误的注释或功能。
我建议检查更简单的情况。例如替换你的实现：
@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();
}
与下一个：
@RuntimeType
public static Object intercept(@RuntimeType Object value) throws Exception {
return value;
}
在这种情况下你避免了递归调用，但可能会有机会检测和分析不同的问题，这很清楚并且与你的情况有关。
可能你也应该注意概念问题。你知道 java 使用 Callable 对象的开发人员不应该直接使用 call()。
按照 API 对 @RuntimeType 的描述，它用于从一个对象映射到另一个对象。出现新问题：为什么需要convert callable object？它将转换为哪种类型（你确定没有 Future 包装器你会有一个对象在那里。可能 null 可能导致你的异常，不是吗？）？