Java Generics Silly Thing (Why can't I specify a type?)

I will try to be short, because the question was not answered. For a detailed explanation, go through this briefing.

I will show what I'm trying to do. Something like this (outputting the input type from the constructor to use it in another getLeaderHerd method as the return type) ...:

public class ZooCage{

    private CageFamily<T> inhabitants;  

    public <T>ZooCage(CageFamily<T> herd) {
        this.inhabitants=herd;      
    }

    public T getHerdLeader() {
        return inhabitants.getLeader();
    }   
}

or

public class ZooCage{

    private (Type) T;   

    public ZooCage(CageFamily<T> herd) {
        this.T=T;       
    }

    public T getHerdLeader() {
        return inhabitants.getLeader();
    }   
}

so that I can call from Main something like:

ZooCage cage = new ZooCage(new CageFamily<Lion>()); //Imagine new CageFamily its not empty
Lion leader = cage.getHerdLeader();

Even if this is not possible, why should I think that it is impractical? Its type is safe if the compiler is intelligent and less redundant, which typifies the ZooCage class, which is not needed

I, m . , , arg. , .

( 2 )

, . :

package Zoo;
import Zoo.Main.CageFamily;
import Zoo.Main.Vertebrate;

public class ZooCage<T extends Vertebrate>{

    private CageFamily<T> inhabitants;  

    public ZooCage(CageFamily<T> herd) {
        this.inhabitants=herd;      
    }

    public T getHerdLeader() {
        return inhabitants.getLeader();
    }   
}

, (/ / )

, Main.java

package Zoo;
import java.util.ArrayList;

public class Main {

    public static void main(String[] args){
        new Main().test();
    }

    public void test(){
        CageFamily<Lion> lionsHerd = new CageFamily<Lion>();
        lionsHerd.add(new Lion("Simba"));
        lionsHerd.add(new Lion("Nala"));

        CageFamily<Bear> bearsHerd = new CageFamily<Bear>();
        bearsHerd.add(new Bear("Yogi"));
        bearsHerd.add(new Bear("Boo-boo"));

        ZooCage<Lion> cageLions = new ZooCage<Lion>(lionsHerd);     
        ZooCage<Bear> cageBears = new ZooCage<Bear>(bearsHerd);

        for (ZooCage<?> cage : new ZooCage[]{cageLions,cageBears} ) 
           System.out.println("The leader is "+ cage.getHerdLeader());

    }

    public interface Vertebrate{
        public String toString();
        public int numBones();
    }
    public class Lion implements Vertebrate{
        private String name;
        public Lion (String name){this.name=name;}
        public String toString(){return name + " (who has "+numBones()+" bones)";}
        public int numBones(){return 345;}
    }
    public class Bear implements Vertebrate{
        private String name;
        public Bear (String name){this.name=name;}      
        public String toString(){return name + " (who has "+numBones()+" bones)";}
        public int numBones(){return 658;}
    }
    public class CageFamily<E extends Vertebrate> extends ArrayList<E>{
        final static long serialVersionUID = 1L;
        public E getLeader(){
             return get(0); //Let,s assume the first added is the leader
        }
    }
}

The leader is Simba (who has bones)
The leader is Yogi (who has bones)

: - ( / ), ZooCage ? ZooCage, s getHerdLeader. ZooCage, . !

, !