初学者的困惑。

java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:274)
at weblogic.rmi.internal.StubGenerator.generateStub(StubGenerator.java:805)
at weblogic.rmi.internal.StubGenerator.generateStub(StubGenerator.java:790)
at weblogic.rmi.extensions.StubFactory.getStub(StubFactory.java:79)
at weblogic.rmi.utils.io.RemoteObjectReplacer.resolveObject(RemoteObjectReplacer.java:222)
at weblogic.rmi.internal.StubInfo.readResolve(StubInfo.java:142)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at java.io.ObjectStreamClass.invokeReadResolve(ObjectStreamClass.java:911)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1655)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1845)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1769)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1646)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:324)
at weblogic.common.internal.ChunkedObjectInputStream.readObject(ChunkedObjectInputStream.java:114)
at weblogic.rjvm.MsgAbbrevInputStream.readObject(MsgAbbrevInputStream.java:111)
at weblogic.rmi.internal.ObjectIO.readObject(ObjectIO.java:56)
at weblogic.rjvm.ResponseImpl.unmarshalReturn(ResponseImpl.java:159)
at weblogic.rmi.internal.BasicRemoteRef.invoke(BasicRemoteRef.java:139)
at weblogic.jdbc.rmi.internal.StatementImpl_weblogic_jdbc_wrapper_Statement_oracle_jdbc_driver_OracleStatement_811_WLStub.executeQuery(Unknown Source)
at weblogic.jdbc.rmi.internal.StatementStub_weblogic_jdbc_rmi_internal_StatementImpl_weblogic_jdbc_wrapper_Statement_oracle_jdbc_driver_OracleStatement_811_WLStub.executeQuery(Unknown Source)
at weblogic.jdbc.rmi.SerialStatement_weblogic_jdbc_rmi_internal_StatementStub_weblogic_jdbc_rmi_internal_StatementImpl_weblogic_jdbc_wrapper_Statement_oracle_jdbc_driver_OracleStatement_811_WLStub.executeQuery(Unknown Source)
at Use_Jdbc.main(Use_Jdbc.java:32)