collection « HashTable « Java Collection Q&A

1. Why does LinkedHashSet extend HashSet and implement Set    stackoverflow.com

Opened a LinkedHashSet source code today and found some interesting thing:

public class LinkedHashSet<E>
    extends HashSet<E>
    implements Set<E>, Cloneable, java.io.Serializable {

2. Correct use of Hashtable with custom class    stackoverflow.com

This piece of code generates unexpected output.

Hashtable<Pair, Integer> results = new Hashtable<Pair, Integer>();
results.put(new Pair(0, 1), 2);
System.out.println("[DBG] " + results.containsKey(new Pair(0, 1)));

3. Merging Two HashTable with removal of duplicates in java    stackoverflow.com

I am having two Hashtables with <int,string> pair. Now they both have duplicate values in each of them, and I want to merge both the hashtables to give me distinct values. ...

4. What is the general purpose of using hashtables as a collection?    stackoverflow.com

Possible Duplicate:
What exactly are hashtables?

5. Is there a Directed Acyclic Graph (DAG) data type in Java, and should I use it?    stackoverflow.com

I am modeling a power subsystem in Java. A simple SQLite database contains a set of Line Replaceable Units (LRUs) and the connections between them. I am writing a Power Model ...

6. How to implement HashTable without the use of Collections Package?    forums.oracle.com