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我发布了几个与javassit链接错误spring Exception when running application on WebSphere with java 8有关的问题。现在经过一些关于这个主题和错误的研究后，我已经获得了一些有关Javassist的字节码操作以解决链接错误的有用信息。如何使用Javassist进行字节码操作来解决链接错误？
供您参考（已贴在这里的另一个问题，该堆栈跟踪）
[10/13/17 ] 00000089 webapp E com.ibm.ws.webcontainer.webapp.WebApp logServletError SRVE0293E: [Servlet Error]-[weblge]: java.lang.ExceptionInInitializerError
at java.lang.J9VMInternals.ensureError(J9VMInternals.java:134)
at java.lang.J9VMInternals.recordInitializationFailure(J9VMInternals.java:123)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:83)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:57)
at java.lang.reflect.Constructor.newInstance(Constructor.java:437)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:120)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:345)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:278)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:103)
at com.ibm.ws.webcontainer.webapp.WebApp.notifyServletContextCreated(WebApp.java:1826)
at com.ibm.ws.webcontainer.webapp.WebAppImpl.initialize(WebAppImpl.java:442)
at com.ibm.ws.webcontainer.webapp.WebGroupImpl.addWebApplication(WebGroupImpl.java:88)
at com.ibm.ws.webcontainer.VirtualHostImpl.addWebApplication(VirtualHostImpl.java:171)
at com.ibm.ws.webcontainer.WSWebContainer.addWebApp(WSWebContainer.java:904)
at com.ibm.ws.webcontainer.WSWebContainer.addWebApplication(WSWebContainer.java:789)
at com.ibm.ws.webcontainer.component.WebContainerImpl.install(WebContainerImpl.java:427)
at com.ibm.ws.webcontainer.component.WebContainerImpl.start(WebContainerImpl.java:719)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:1247)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.fireDeployedObjectStart(DeployedApplicationImpl.java:1514)
at com.ibm.ws.runtime.component.DeployedModuleImpl.start(DeployedModuleImpl.java:704)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.start(DeployedApplicationImpl.java:1096)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:799)
at com.ibm.ws.runtime.component.ApplicationMgrImpl$5.run(ApplicationMgrImpl.java:2315)
at com.ibm.ws.security.auth.ContextManagerImpl.runAs(ContextManagerImpl.java:5488)
at com.ibm.ws.security.auth.ContextManagerImpl.runAsSystem(ContextManagerImpl.java:5614)
at com.ibm.ws.security.core.SecurityContext.runAsSystem(SecurityContext.java:255)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:2320)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:436)
at com.ibm.ws.runtime.component.CompositionUnitImpl.start(CompositionUnitImpl.java:123)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:379)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.access$500(CompositionUnitMgrImpl.java:127)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl$CUInitializer.run(CompositionUnitMgrImpl.java:985)
at com.ibm.wsspi.runtime.component.WsComponentImpl$_AsynchInitializer.run(WsComponentImpl.java:524)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1909)
Caused by: java.lang.IllegalStateException: javassist.CannotCompileException: by java.lang.LinkageError: org.springframework.aop.framework.ProxyCreatorSupport
at org.springframework.aop.framework.JavassistApplicationContext.<clinit>(JavassistApplicationContext.java:36)
... 34 more
Caused by: javassist.CannotCompileException: by java.lang.LinkageError: org.springframework.aop.framework.ProxyCreatorSupport
at javassist.ClassPool.toClass(ClassPool.java:1170)
at javassist.ClassPool.toClass(ClassPool.java:1113)
at javassist.ClassPool.toClass(ClassPool.java:1071)
at javassist.CtClass.toClass(CtClass.java:1275)
at org.springframework.aop.framework.JavassistApplicationContext.<clinit>(JavassistApplicationContext.java:34)
... 34 more
Caused by: java.lang.LinkageError: org.springframework.aop.framework.ProxyCreatorSupport
at java.lang.ClassLoader.defineClassImpl(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:357)
at java.lang.ClassLoader.defineClass(ClassLoader.java:293)
at sun.reflect.GeneratedMethodAccessor17.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
at java.lang.reflect.Method.invoke(Method.java:508)
at javassist.ClassPool.toClass2(ClassPool.java:1183)
at javassist.ClassPool.toClass(ClassPool.java:1164)
... 38 more
和我对这个Java文件收到此错误，当我试图做操作org.springframework.aop.framework.ProxyCreatorSupport
package org.spring.aop.framework;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.LoaderClassPath;
import org.springframework.web.context.support.XmlWebApplicationContext;
public class JavassistApplicationContext extends XmlWebApplicationContext {
static {
ClassPool classPool = ClassPool.getDefault();
try {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
classPool.appendClassPath(new LoaderClassPath(classLoader));
CtClass cc = classPool.get("org.spring.aop.framework.ProxyCreatorSupport");
CtConstructor c = cc.getConstructors()[0];
c.insertAfter("$0.aopProxyFactory = new org.spring.aop.framework.JavassistAopProxyFactory();");
cc.toClass();
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
}
就行cc.toClass();，我得到这个例外。我在WebSphere上尝试了不同的类加载器方法来解决此异常并获得相同的错误。
现在我明白，linkage problem is occur when tries to modify the class already loaded by referenced classloader .能够解决这个错误，我should unload the class first from the reference classloader，我认为这是困难的。
- 所以我认为唯一的方法来解决这个问题，通过任何类加载器之前的类加载器实现字节码操作。是不是？
- 如何将我现有的代码更改为使用java代理的字节码操作？任何想法和建议？请不要把它作为一个重复的问题。这只是上一个问题的参考工作。
有什么建议吗？ –