设置:我有一些格式化程序的接口(interface):interfaceFormatter{Stringformat(Titem);}我有一个工厂创建这样的格式化程序:publicclassFactory{publicstaticFormattercreate(){switch(something){caseSOMETHING:returnnewFormatter(){Stringformat(SomeItemitem){...}};caseSOMETHING_ELSE:returnnewFormatter(){Stringformat(OtherItemitem){...}};}现在

假设我们有一个包含此类的程序:publicinterfaceAbstractItem{}publicSharpItemimplementsAbstractItem{}publicBluntItemimplementsAbstractItem{}publicinterfaceAbstractToolbox{//welltheproblemstartshere...publicListgetItems();}publicExpensiveToolboximplementsAbstractToolbox{privateListitems=newArrayList();publicListge