Java Collections Framework Documentation

Java Collections Framework (JCF) is a set of interfaces and classes that provide reusable data structures. It is widely used in Java applications for managing collections of objects. This document provides an overview of the JCF, its components, and usage.

Overview

The Java Collections Framework provides a wide range of data structures, including lists, sets, queues, stacks, and maps. These data structures are implemented as classes and interfaces, which can be used to store and manipulate collections of objects.

Key Components

Interfaces: These define the operations that can be performed on collections.
Classes: These implement the interfaces and provide concrete implementations of the data structures.
Algorithms: These are methods that operate on collections, such as sorting and searching.

Data Structures

Here are some of the key data structures provided by the JCF:

List: An ordered collection that allows duplicate elements. Common implementations include ArrayList and LinkedList.
Set: A collection that contains no duplicate elements. Common implementations include HashSet and TreeSet.
Queue: A collection that orders elements in a specified order. Common implementations include LinkedList and PriorityQueue.
Map: A collection that associates keys with values. Common implementations include HashMap and TreeMap.

Usage

The JCF is used in a variety of applications, including:

Data storage: Storing and retrieving objects.
Data processing: Sorting and searching collections.
Concurrency: Managing shared data structures in a multi-threaded environment.

Example

Here's an example of how to use a List to store a collection of integers:

import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = new ArrayList<>();
        numbers.add(1);
        numbers.add(2);
        numbers.add(3);

        System.out.println(numbers);
    }
}

For more information on Java Collections Framework, you can visit the official documentation.