Package modernfeatures.java9.collections

Class CollectionFactoryMethodsDemo

java.lang.Object

modernfeatures.java9.collections.CollectionFactoryMethodsDemo

public class CollectionFactoryMethodsDemo
extends Object

Demonstrates the use of Java 9 collection factory methods.

Java 9 introduced convenient static factory methods for creating immutable collections:

• List.of()
• Set.of()
• Map.of()

These methods allow concise creation of collections that are unmodifiable (immutable). Attempting to modify them results in UnsupportedOperationException.

Example usage:

   List<String> names = List.of("Alice", "Bob", "Carol");
   Set<Integer> numbers = Set.of(1, 2, 3, 4, 5);
   Map<String, Integer> ages = Map.of("Alice", 30, "Bob", 25);
 

Constructor Summary

Constructors

Constructor	Description
CollectionFactoryMethodsDemo()

Method Summary

Modifier and Type	Method	Description
static void	main(String[] args)	Demonstrates creation of immutable collections using Java 9 factory methods, and shows that modification attempts result in exceptions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

CollectionFactoryMethodsDemo

public CollectionFactoryMethodsDemo()

Method Details

main

public static void main(String[] args)

Demonstrates creation of immutable collections using Java 9 factory methods, and shows that modification attempts result in exceptions.

This method performs the following steps:

• Creates an immutable List using List.of() and prints it.
• Creates an immutable Set using Set.of() and prints it.
• Creates an immutable Map using Map.of() and prints it.
• Attempts to modify each collection to demonstrate that they throw UnsupportedOperationException.

Parameters:

args - command-line arguments (not used)