dhsrocha’s gists

dhsrocha / Node.java

Last active April 22, 2025 15:55

Java class with methods for managing neighbors and finding the shortest path with different search strategies.

	import java.util.Collection;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import java.util.PriorityQueue;

dhsrocha / Bus.java

Created April 9, 2025 16:08

The Bus class is a thread-safe message bus that implements the Producer-Consumer pattern, allowing asynchronous message handling. It uses a BlockingQueue for queuing messages and an ExecutorService for processing them via an observer.

	import java.util.Objects;
	import java.util.concurrent.BlockingQueue;
	import java.util.concurrent.ExecutorService;
	import java.util.concurrent.LinkedBlockingQueue;
	import java.util.concurrent.atomic.AtomicBoolean;
	import java.util.function.Consumer;

	/**
	* A thread-safe message bus that allows for asynchronous message handling.
	* <p>

dhsrocha / Validator.java

Last active April 9, 2025 16:06

Chainable validation mechanism that allows for the sequential application of predicates to a specified generic subject. Each predicate can be associated with a custom error message, which is used for reporting when a validation fails.

	import java.util.Objects;
	import java.util.function.Function;
	import java.util.function.Predicate;

	/**
	* A class that represents a chain of predicates that can be applied to a subject.
	* <p>
	* Each predicate can have an associated message that is used for error reporting if the predicate
	* test fails.
	*

dhsrocha / Broker.java

Last active April 3, 2025 09:42

Thread-safe publish-subscribe mechanism to It allows subscribers to register themselves for event notifications without preventing garbage collection.

	import java.lang.ref.Reference;
	import java.lang.ref.ReferenceQueue;
	import java.lang.ref.WeakReference;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.List;
	import java.util.Objects;
	import java.util.concurrent.CompletableFuture;
	import java.util.concurrent.CopyOnWriteArrayList;
	import java.util.concurrent.CopyOnWriteArraySet;

dhsrocha / ocr.py

Created March 24, 2025 17:26

Extract text from PDF files.

	import logging
	import os

	import PyPDF2
	import fitz
	import pytesseract
	from PIL import Image
	from fpdf import FPDF

	# Configure logging

dhsrocha / FSM.java

Last active April 2, 2025 08:26

A generic finite state machine implementation for managing stateful transitions.

	import java.util.EnumMap;
	import java.util.Map;
	import java.util.Objects;
	import java.util.function.UnaryOperator;

	/**
	* A generic finite state machine implementation for managing state transitions.
	*
	* @param <S> the type of the state, which must be an enum.
	* @param <D> the type of the data associated with the states.

dhsrocha / Cache.java

Last active July 23, 2024 14:16

Generic cache interface and default implementation for JDK 11+

	import java.time.LocalDateTime;
	import java.time.temporal.ChronoUnit;
	import java.util.Map;
	import java.util.Optional;
	import java.util.Set;
	import java.util.concurrent.ConcurrentHashMap;
	import java.util.concurrent.locks.ReadWriteLock;
	import java.util.concurrent.locks.ReentrantReadWriteLock;
	import java.util.function.Supplier;
	import java.util.stream.Collectors;

dhsrocha / Client.java

Created January 1, 2024 21:38

https://stackoverflow.com/questions/40565846/wait-for-a-background-process-to-end-with-swingworker-from-a-different-class#40566230

	package com.ludo.adapter.awt;

	import java.awt.BorderLayout;
	import java.awt.Dialog;
	import java.awt.EventQueue;
	import java.awt.event.ActionEvent;
	import java.awt.event.KeyEvent;
	import java.beans.PropertyChangeEvent;
	import java.beans.PropertyChangeListener;
	import java.io.BufferedReader;

dhsrocha / rebase-develop.sh

Last active March 1, 2023 16:57

Function to rebase all branches from reference one,

	#!/bin/sh

	# rebase() - Rebase all branches from the specified source branch
	#
	# Usage:
	# rebase <source-branch>
	#
	# Description:
	# This function will check if git is on the PATH, and if the argument "$1"
	# has been provided. If not, an error message will be printed and the

dhsrocha / Passwords.java

Created February 4, 2023 10:44

Third-party-free password generator. Inspired by https://stackoverflow.com/questions/18142745/how-do-i-generate-a-salt-in-java-for-salted-hash

	import java.security.NoSuchAlgorithmException;
	import java.security.SecureRandom;
	import java.security.spec.InvalidKeySpecException;
	import java.util.Arrays;
	import java.util.Random;
	import javax.crypto.SecretKeyFactory;
	import javax.crypto.spec.PBEKeySpec;

	/**
	* A utility class to hash passwords and check passwords vs hashed values. It uses a combination of

Diego Rocha dhsrocha