我有一个包含以下组件的项目:publicabstractclassBaseThing{publicabstractThingDoergetThingDoer();}publicclassSomeThingextendsBaseThing{publicThingDoergetThingDoer(){returnThings.getSomeThingDoer();}}publicclassSomeOtherThingextendsBaseThing{publicThingDoergetThingDoer(){returnThings.getSomeOtherThingDoer();}}pu

为什么这段代码不能编译？publicclassx{privatevoidtest(){handle(newThingA());handle(newModifiedThingA());}private,XextendsT>java.util.Listhandle(Xobject){returnobject.getList();}privatestaticclassBaseThing>{publicjava.util.ListgetList(){returnnull;}}privatestaticclassThingAextendsBaseThing{}privatestaticclass