Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
537 views
in Technique[技术] by (71.8m points)

generics - Java class with concrete type as parameter

Is there any point in declaring a class with "concrete" types as generics?

If yes, what's the use for it?

If no, any specific reason why the compiler is allowing it?

The code:

public class SomeClass<Integer> {  

    //...

    public static void main (String a[]) {
        // SomeClass <> iSome = new SomeClass<>();
        // SomeClass <Integer> jSome = new SomeClass<>();

        SomeClass <Double> kSome = new SomeClass<>();

        // ...
    }
}

is running fine, and is giving compiler errors when I uncomment the lines declaring iSome and jSome.

I'm trying to put things together in "deciphering" the generics.

Thanks in advance.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

It's not what you think. You're creating a generic type parameter called Integer which shadows java.lang.Integer.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...