泛型简介，泛型类及使用

public class GenericDemo2{
public static void main(String []args){
//一个泛型类继承另一个泛型类
SubClass<String,Integer> sub=new SubClass<String,Integer>("张三",20);
System.out.println(sub.show1());
//实现接口的方法
sub.show2(100);
}
}

class SuperClass<T1>{
private T1 var1;
public SuperClass(T1 var1){
this.var1=var1;
}

public T1 show1(){
return var1;
}
}

interface IInfo<T2>{
public void show2(T2 var3);
}

class SubClass<T1,T2> extends SuperClass<T1> implements IInfo<T2>{
private T2 var2;
public SubClass(T1 var1,T2 var2){
super(var1);
this.var2=var2;
}
//重写父类的方法
public T1 show1(){
return super.show1();
}
//实现接口的方法
public void show2(T2 var3){
System.out.println(var3);
System.out.println(var2);
//虽然都是Integer类型，但泛型会先将其转为Object类型，所以不能相加
//System.out.println(var2+var3);
}
}