不同的是，当你使用原始类型时，所有成员签名中的泛型引用也被转换为它们的原始形式.如此有效地调用了一个现在具有如下签名的方法:

The difference is that when you use the raw type, all the generic references within the member signatures are converted to their raw forms too. So effectively you're calling a method which now has a signature like this:

List getList()

现在至于为什么你的最终版本会编译——虽然它会编译，但如果你使用 -Xlint 会有一个警告:

Now as for why your final version compiles - although it does, there's a warning if you use -Xlint:

Generics.java:16: warning: [unchecked] unchecked conversion
    List<String> list = generics.getList();
                                        ^

这类似于:

 List list = new ArrayList();
 List<String> strings = list;

... 也可以编译，但在 -Xlint 下有警告.

... which also compiles, but with a warning under -Xlint.

故事的寓意:不要使用原始类型！

The moral of the story: don't use raw types!