評論里好幾個討論這個問題，剛好在StackOverflow上看到對這個問題的說明。
JAVA泛型通配符T，E，K，V區(qū)別，T以及Class<T>，Class<?>的區(qū)別1. 先解釋下泛型概念 泛型是Java SE 1.5的新特性，泛型的本質(zhì)是參數(shù)化類型，也就是說所操作的數(shù)據(jù)類型被指定為一個參數(shù)。這種參數(shù)類型可以用在類、接口和方法的創(chuàng)建中，分...
Many assume that because class C inherits from class P, that List<C> also inherits from List<P>. But this is not the case. Although String is a subset of Object, but List<String> is not inherited from List<Object>.The reason why was that if we could cast from List<String> to List<Object>, then we could put Objects into that list, thus violating the original contract of List<String> when attempting to retrieve an element.
JAVA泛型通配符T，E，K，V區(qū)別，T以及Class<T>，Class<?>的區(qū)別1. 先解釋下泛型概念 泛型是Java SE 1.5的新特性，泛型的本質(zhì)是參數(shù)化類型，也就是說所操作的數(shù)據(jù)類型被指定為一個參數(shù)。這種參數(shù)類型可以用在類、接口和方法的創(chuàng)建中，分...
