Writing generic classes

The following class can accept and return any type of object.

It cannot, however, accept primitive types (그러나 기본 유형을 허용할 수는 없습니다.)

public class Box {
	private Object object;
    public void set (Object object){
    	this.object = object;
    }
    public Object get(){
    	return object;
    }
}

 

If we want to create a class that can accept and return any type, we need to replace references in our code to Object with a generic type variable T.

 

public class Box<T> {
	private T t;
    public void set (T t){
    	this.t = t;
    }
    public T get(){
    	return t;
    }
}

 

 

In a generic class,  the <> following the class name is the type parameter.

This is how you would instaniate an object of Box class that can accept and return any type:

 

* following 다음 instaniate 인스턴스화 하다.

* This is how you would instaniate  이것이 당신이 인스턴스화하는 방법입니다

* This is how you would 이것이 당신이 ~ 하는 입니다

 

Box<Integer> box1 = new Box<Integer>();

Box<Integer> box2 = new Box<>();