jacorb编译java类

Question

我正在尝试编译这个java类MyServerStub。但是我得到了这个错误

cannot find symbol
symbol  : class ServantObjectExt
location: package org.omg.CORBA.portable
                if ( _so instanceof org.omg.CORBA.portable.ServantObjectExt) 
                                                          ^
stock/_MyServerStub.java:83: cannot find symbol
symbol  : class ServantObjectExt
location: package org.omg.CORBA.portable
                    ((org.omg.CORBA.portable.ServantObjectExt)_so).normalCompletion();
                                            ^
stock/_MyServerStub.java:88: cannot find symbol
symbol  : class ServantObjectExt
location: package org.omg.CORBA.portable
                if ( _so instanceof org.omg.CORBA.portable.ServantObjectExt) 
                                                          ^
stock/_MyServerStub.java:89: cannot find symbol
symbol  : class ServantObjectExt
location: package org.omg.CORBA.portable
                    ((org.omg.CORBA.portable.ServantObjectExt)_so).exceptionalCompletion(re);
                                            ^
stock/_MyServerStub.java:94: cannot find symbol
symbol  : class ServantObjectExt
location: package org.omg.CORBA.portable
                if ( _so instanceof org.omg.CORBA.portable.ServantObjectExt) 
                                                          ^
stock/_MyServerStub.java:95: cannot find symbol
symbol  : class ServantObjectExt
location: package org.omg.CORBA.portable
                    ((org.omg.CORBA.portable.ServantObjectExt)_so).exceptionalCompletion(err);
                                            ^
6 errors

_myserver stub。java是从jacORB生成的存根，因此代码没有错