Java: extends 后有&是什么意思

Question

看待一段代码，一个类的定义，其中&BaseEnum>extendsBaseTypeHandler

Answer 1

packageTypeVarMembers;
classC{
publicvoidmCPublic(){}
protectedvoidmCProtected(){}
voidmCPackage(){}
privatevoidmCPrivate(){}
}
interfaceI{
voidmI();
}
classCTextendsCimplementsI{
publicvoidmI(){}
}
classTest{
voidtest(Tt){
t.mI();//OK
t.mCPublic();//OK
t.mCProtected();//OK
t.mCPackage();//OK
t.mCPrivate();//Compile-timeerror
}
}
ThetypevariableThasthesamemembersastheintersectiontypeC&I,whichinturnhasthesamemembersastheemptyclassCT,definedinthesamescopewithequivalentsupertypes.Themembersofaninterfacearealwayspublic,andthereforealwaysinherited`(unlessoverridden).HencemIisamemberofCTandofT.AmongthemembersofC,allbutmCPrivateareinheritedbyCT,andarethereforemembersofbothCTandT.IfChadbeendeclaredinadifferentpackagethanT,thenthecalltomCPackagewouldgiverisetoacompile-timeerror,asthatmemberwouldnotbeaccessibleatthepointwhereTisdeclared.来自TheJava®LanguageSpecification,JavaSE8Edition$4.4TypeVariablesP58~59
                            

Answer 2

1楼正解&在java中是and的意思，在泛型的应用场景，含义基本不变。publicclassEnumTypeHandler&BaseEnum>extendsBaseTypeHandler中的EextendsEnum&BaseEnum可以理解为Eextends(Enum&BaseEnum)，结合extends的含义，及E为Enum和BaseEnum的子类