Feature implementation from commits acb40e1..e359f1b

[yashuatla]

PR Summary

Actor Model Pattern Implementation with Minor Refactoring

Overview

This PR introduces a new Actor Model design pattern implementation and includes various code refactoring improvements across multiple packages.

Change Types

Type	Description
Feature	New Actor Model pattern implementation with complete actor system, message passing, and example actors
Refactor	Code improvements in multiple packages including simplified lambda expressions, improved Optional usage, and JUnit test enhancements
Test	Added tests for the new Actor Model implementation

---

Affected Modules

Module / File	Change Description
com.iluwatar.actormodel.*	New Actor Model pattern implementation with Actor, ActorSystem, Message classes and examples
com.iluwatar.idempotentconsumer.*	Refactored to use Optional.orElseGet() and improved test method naming
com.iluwatar.Money	Simplified using Lombok's @AllArgsConstructor
com.iluwater.money.MoneyTest	Refactored multi-line lambda expressions to single-line format
com.iluwatar.monolithic.*	Simplified test assertions with single-line lambda expressions
com.iluwatar.publish.subscribe.*	Improved stream operations and reduced visibility modifiers
com.iluwatar.servicestub.*	Changed ternary to switch expression and improved JavaDoc
com.iluwatar.sessionfacade.*	Refactored tests to use parameterized testing
com.iluwatar.table.inheritance.*	Package declaration fixes and JUnit 5 convention alignment

---

Notes for Reviewers

• The Actor Model implementation follows the concurrent programming paradigm with message passing between actors
• Test refactoring follows modern JUnit 5 best practices with reduced visibility modifiers
• Lambda expressions have been simplified throughout test code for better readability

[codeowlai]

🐛 Correctness Issue

Null message handling missing in send().

The send() method doesn't check for null messages, which will cause NullPointerException when processing the message in onReceive().

Current Code (Diff):

-   public void send(Message message) {
-     mailbox.add(message); // Add message to queue
-   }
+   public void send(Message message) {
+     if (message == null) {
+       throw new IllegalArgumentException("Message cannot be null");
+     }
+     mailbox.add(message); // Add message to queue
+   }

📝 Committable suggestion

‼️ IMPORTANT
Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	public void send(Message message) {
	public void send(Message message) {
	if (message == null) {
	throw new IllegalArgumentException("Message cannot be null");
	}
	mailbox.add(message); // Add message to queue
	}

[codeowlai]

🐛 Correctness Issue

Improper handling of InterruptedException.

The catch block only resets the interrupt flag but doesn't properly handle actor termination, which could lead to thread leaks.

Current Code (Diff):

-       } catch (InterruptedException e) {
-         Thread.currentThread().interrupt();
-       }
+       } catch (InterruptedException e) {
+         Thread.currentThread().interrupt();
+         active = false; // Ensure actor terminates when interrupted
+       }

📝 Committable suggestion

‼️ IMPORTANT
Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	} catch (InterruptedException e) {
	} catch (InterruptedException e) {
	Thread.currentThread().interrupt();
	active = false; // Ensure actor terminates when interrupted

[codeowlai]

⚡ Performance Issue

Unbounded Thread Pool Risk.

Using an unbounded cached thread pool can lead to resource exhaustion under high load, potentially causing OutOfMemoryError.

Current Code (Diff):

-   private final ExecutorService executor = Executors.newCachedThreadPool();
+   private final ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

📝 Committable suggestion

‼️ IMPORTANT
Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	private final ExecutorService executor = Executors.newCachedThreadPool();
	private final ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

[codeowlai]

🐛 Correctness Issue

Package name mismatch with imported classes.

The test class is in package 'com.iluwatar.actor' but imports classes from 'com.iluwatar.actormodel', which could cause class resolution issues.

Current Code (Diff):

- package com.iluwatar.actor;
+ package com.iluwatar.actormodel;

📝 Committable suggestion

‼️ IMPORTANT
Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	package com.iluwatar.actor;
	package com.iluwatar.actormodel;

[codeowlai]

🐛 Correctness Issue

Incorrect assertion comment.

The comment states 'Check that Srijan received the message' but the assertion actually checks if Ansh received the message, which verifies the wrong behavior.

Current Code (Diff):

-     // Check that Srijan received the message
+     // Check that Ansh received the message

📝 Committable suggestion

‼️ IMPORTANT
Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	// Check that Srijan received the message
	// Check that Ansh received the message

[codeowlai]

🐛 Correctness Issue

Malformed package declaration with embedded comment.

The package declaration has an embedded multi-line comment which will cause a compilation failure as Java doesn't allow comments within package declarations.

Current Code (Diff):

- package com.iluwatar.table.inheritance; /*
+ package com.iluwatar.table.inheritance;
+ /*

📝 Committable suggestion

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Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	package com.iluwatar.table.inheritance; /*
	package com.iluwatar.table.inheritance;

[codeowlai]

🐛 Correctness Issue

Malformed package declaration with embedded comment.

The package declaration has a license comment embedded in the same line, which will cause compilation failure as package declarations must be standalone statements.

Current Code (Diff):

- package com.iluwatar.table.inheritance; /*
+ package com.iluwatar.table.inheritance;
+ /*

📝 Committable suggestion

‼️ IMPORTANT
Trust, but verify! 🕵️ Please review this suggestion with the care of a code archaeologist - check that it perfectly replaces the highlighted code, preserves all lines, maintains proper indentation, and won't break anything in production. Your future self will thank you! 🚀

Suggested change

	package com.iluwatar.table.inheritance; /*
	package com.iluwatar.table.inheritance;