我正在测试Java(Java8)的新主要更新，它非常有趣。我正在使用流；特别是我正在使用这个简单的代码。privatevoidgetAvg(){finalArrayListpersons=newArrayList(Arrays.asList(newMyPerson("Ringo","Starr"),newMyPerson("John","Lennon"),newMyPerson("Paul","Mccartney"),newMyPerson("George","Harrison")));finalOptionalDoubleaverage=persons.stream().filter

如下示例代码所示://DefineyourmodelslikeregularSwiftclassesclassDog:Object{dynamicvarname=""dynamicvarage=0}classPerson:Object{dynamicvarname=""dynamicvarpicture:NSData?=nil//optionalssupportedletdogs=List()}//UsethemlikeregularSwiftobjectsletmyperson=Person()letmydog=Dog()mydog.name="Rex"myperson.dogs.a