泛型的上限

/*受限泛型：泛型的上限（在类定义时指定泛型的上限）*/

class Info2<T extends Number>{

private T var;

public T getVar() {

return var;

}

public void setVar(T var) {

this.var = var;

}

public String toString(){

return this.var.toString();

}

}

public class GenericsDemo5 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Info2<Integer> i1 = new Info2<Integer>();

i1.setVar(28);

System.out.println("内容："+i1);

}

}