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[Javassist]「javassist.CannotCompileException: cannot find ~"」の解決方法
はじめに
Javassist の CtBehavior#insertBefore メソッドを利用した際に javassist.CannotCompileException が発生したので、その解決方法をメモ。
具体的には以下のエラーメッセージ
javassist.CannotCompileException: cannot find okhttp3.Request
コード
エラーが発生したJavaコードは以下の通りです。
okhttp3/internal/http/RealInterceptorChain#proceed メソッドに前処理を追加してます。
package org.example.agent05;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
import java.io.ByteArrayInputStream;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.lang.instrument.Instrumentation;
import java.security.ProtectionDomain;
public class MyAgent {
public static void premain(String agentArg, Instrumentation inst) {
inst.addTransformer(new ClassFileTransformer() {
@Override
public byte[] transform(ClassLoader loader,
String className,
Class<?> classBeingRedefined,
ProtectionDomain protectionDomain,
byte[] classfileBuffer) throws IllegalClassFormatException {
if ( className.equals("okhttp3/internal/http/RealInterceptorChain") ) {
try {
ClassPool classPool = new ClassPool();
CtClass ctClass = classPool.makeClass(new ByteArrayInputStream(classfileBuffer));
CtMethod ctMethod = ctClass.getDeclaredMethod("proceed");
ctMethod.insertBefore("System.out.println(\"Hook proceed method.\");");
return ctClass.toBytecode();
} catch ( Exception ex ) {
ex.printStackTrace();
return new byte[0];
}
} else {
return new byte[0];
}
}
});
}
}
エラーメッセージ
「okhttp3.Request」が見つからないとのこと。
javassist.CannotCompileException: cannot find okhttp3.Request
at javassist.CtBehavior.insertBefore(CtBehavior.java:803)
at javassist.CtBehavior.insertBefore(CtBehavior.java:766)
at org.example.agent05.MyAgent$1.transform(MyAgent.java:28)
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:756)
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:418)
at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:223)
at okhttp3.RealCall.execute(RealCall.java:81)
at com.example.demo.controllers.api.ApiDemoController.ssrf1(ApiDemoController.java:83)
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.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:894)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1061)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961)
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:626)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
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:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$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)
Caused by: javassist.NotFoundException: okhttp3.Request
at javassist.ClassPool.get(ClassPool.java:422)
at javassist.bytecode.Descriptor.toCtClass(Descriptor.java:571)
at javassist.bytecode.Descriptor.getParameterTypes(Descriptor.java:424)
at javassist.CtBehavior.getParameterTypes(CtBehavior.java:323)
at javassist.CtBehavior.insertBefore(CtBehavior.java:781)
... 69 more
解決方法
方法①
ClassPool#appendClassPathメソッドを使う。
appendClassPath(ClassPath cp)
Appends a ClassPath object to the end of the search path.
ClassPool classPool = new ClassPool();
classPool.appendClassPath(new LoaderClassPath(loader)); // 追加
方法②
ClassPool#insertClassPath メソッドを使う。
insertClassPath(java.lang.String pathname)
Inserts a directory or a jar (or zip) file at the head of the search path.
ClassPool classPool = new ClassPool();
classPool.insertClassPath("~/.gradle/caches/modules-2/files-2.1/com.squareup.okhttp3/okhttp/3.14.9/3e6d101343c7ea687cd593e4990f73b25c878383/okhttp-3.14.9.jar"); // 追加
そして翌日...。同様のエラーが発生...。そして解決
エラーメッセージ
次は、「java.nio.file.Path」が見つからないとのこと。
javassist.CannotCompileException: cannot find java.nio.file.Path
at javassist.CtBehavior.insertBefore(CtBehavior.java:803)
（以下略）
解決方法
ClassPool#appendSystemPath を追加したら解決しました。
appendSystemPath()
Appends the system search path to the end of the search path.
ClassPool classPool = new ClassPool();
classPool.appendSystemPath(); // 追加
classPool.appendClassPath(new LoaderClassPath(loader));
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