Java版本为openjdk 1.6.0_17, tomcat版本为7.0.12，本人为获取tomcat运行时的字节码，采用了agentmain，其基本思路是将获取的class文件的字节流发送特定的端口，但是出现了如下的问题：特定端口所在的进程显示

com.sun.tools.attach.AgentInitializationException: Agent JAR loaded but agent failed to initialize
	at sun.tools.attach.HotSpotVirtualMachine.loadAgent(HotSpotVirtualMachine.java:121)
	at com.sun.tools.attach.VirtualMachine.loadAgent(VirtualMachine.java:526)
	at tjvm.executor.Attach.attach(Attach.java:21)
	at tjvm.ServiceMonitor.ServiceMonitor.run(ServiceMonitor.java:62)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:636)

tomcat的显示如下的问题：

Exception in thread "Attach Listener" java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:343)
	at sun.instrument.InstrumentationImpl.loadClassAndCallAgentmain(InstrumentationImpl.java:368)
Caused by: java.lang.InternalError
	at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
	at sun.instrument.InstrumentationImpl.retransformClasses(InstrumentationImpl.java:144)
	at agentmain.Agent.agentmain(Agent.java:21)
	... 6 more

请问这是什么缘故呀，3ks。