In fact, InputStream is abstract, so some sort of subclass is necessary.

实际上，InputStream是一个抽象类，因此某种类型的子类是必要的。

youdao

In fact, InputStream is abstract, so some sort of subclass is necessary.

实际上，InputStream是一个抽象类，因此某种类型的子类是必要的。

youdao