Generic « Set « Java Collection Q&A

1. Java: Problems with TreeSet    stackoverflow.com

I have a class Odp. I want to use TreeSet to keep a sorted collection of Odp objects. However, I've been having problems.

public class OdpStorage {

    private TreeSet<Odp> ...

2. What is unchecked and unsafe operation here?    stackoverflow.com

I have the following code:

private static final Set<String> allowedParameters;
static {
    Set<String> tmpSet = new HashSet();
    tmpSet.add("aaa");
    allowedParameters = Collections.unmodifiableSet(tmpSet);
}

Note: mygame/Game.java ...

3. Generics and TreeSets    stackoverflow.com

Working with Generics is definitely my weak spot, and can use some help with this. The project is to develop a simple order/inventory system that places orders, keeps track of items and ...

4. wildcard generics in HashSet constructor    stackoverflow.com

The java HashSet implementation has a constructor:

public HashSet(Collection<? extends E> c) {
    map = new HashMap<E,Object>(Math.max((int) (c.size()/.75f) + 1, 16));
    addAll(c);
} 

5. Why is it possible to access a field without a getter?    stackoverflow.com

I have the following example:

package cage;

import java.util.HashSet;
import java.util.Set;

import animals.Animal;

public class Cage<T extends Animal> {  //A cage for some types of animals
    private Set<T> set = new HashSet<T>();

 ...

6. Generics and Collections: Duplicates in HashSet allowed?    coderanch.com

Hello, I am confused. According to the API a Set is "a collection that contains no duplicate elements. More formally, sets contain no pair of elements e1 and e2 such that e1.equals(e2)...". In my code below however I am able to add duplicates though equals() keeps telling me that the Objects in questions (p1 and p2) are equal. Due to my ...