LostInformation.java

package com.brianway.learning.java.base.generics;//: generics/LostInformation.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class LostInformation {
    public static void main(String[] args) {
        List<Frob> list = new ArrayList<Frob>();
        Map<Frob, Fnorkle> map = new HashMap<Frob, Fnorkle>();
        Quark<Fnorkle> quark = new Quark<Fnorkle>();
        Particle<Long, Double> p = new Particle<Long, Double>();
        System.out.println(Arrays.toString(
                list.getClass().getTypeParameters()));
        System.out.println(Arrays.toString(
                map.getClass().getTypeParameters()));
        System.out.println(Arrays.toString(
                quark.getClass().getTypeParameters()));
        System.out.println(Arrays.toString(
                p.getClass().getTypeParameters()));
    }
}

class Frob {
}

class Fnorkle {
}

class Quark<Q> {
}

class Particle<POSITION, MOMENTUM> {
}

/* Output:
[E]
[K, V]
[Q]
[POSITION, MOMENTUM]
*///:~