Ralph's Blog

In this blog post, we take a closer look at how to receive push notifications with Capacitor and how to send them from a Spring Boot application.

How to back up your data with restic, an easy, fast, efficient, secure, and free command-line tool.

In this blog post, we are going to take a look at the JSON-P (JSR 374) standard for processing JSON in Java.

In this blog post, we build a passwordless sign-in flow with WebAuthn, an Angular front end, and a Spring Boot back end secured with Spring Security.

Sending Web Push notifications from a Java back end to a web browser

A closer look at Ky, a tiny HTTP client built on top of the Fetch API for browsers, Node.js, Bun, and Deno.

How to use catch-all SMTP servers for development and testing email delivery.

How to rate limit Spring MVC HTTP endpoints with bucket4j

Hibernate Envers adds audit history to Jakarta Persistence entities and lets you query historical revisions with a small amount of code.

In this blog post, we take a look at JGit, a pure Java implementation of Git.

This blog post explains when Web Workers help, how message passing and transferables work, how Angular CLI supports workers today, and how Comlink simplifies the Web Worker programming model.

In this blog post, we develop an Angular/Ionic application that runs optical character recognition (OCR) in a browser with Tesseract.js.

What the Page Visibility API is, how to use it in modern web applications, and how a few small native helpers can remove repetitive visibility checks.

Installing WireGuard, a simple, fast, and modern VPN, on Windows and connecting to a WireGuard server.

In this blog post, you learn how to build an authentication system with Spring Security that uses username/password and TOTP (Time-based One-Time Password) as a second factor

How to encode fixed 4-byte Java integers into a variable-length format that uses less space.

How to create a frictionless password auto-login experience with the Credential Management API.

How to expose version numbers, build timestamps, and Git metadata in Spring Boot and Angular applications

How to take pictures with the Capacitor camera plugin and upload them to a Spring Boot application with Angular's HttpClient and tus.io.

How to integrate tus.io implementations into JavaScript and Java applications to create reliable and resumable file uploads over HTTP.

A tutorial on how to use Google Fonts in an Angular / Ionic app.

This post implements a stateless authentication system with Spring Security, Spring Boot, and an Angular/Ionic client

This blog post shows how to integrate Font Awesome icons into a modern standalone Angular and Ionic application with the official Angular library.

How to self-host Seafile, an open-source file sync and share software, on a VPS with Docker

In this blog post, we take a look at Java's ability to monitor directories for changes, a feature that was introduced in Java 7 in 2011.

In this blog post, we are going to set up a Spring Boot application with jOOQ and Flyway

In this blog post, we will take a closer look at the new HTTP Client introduced in Java 11.

A collection of examples with the spread and rest syntax in JavaScript

In this blog post, I show how to set up a WireGuard VPN between a computer behind a NAT or firewall and a VPS in the cloud, exposing services running on the private server to the Internet and making them accessible from anywhere.

In this blog post, I show how to make services installed on a server behind a NAT or firewall accessible from anywhere through the Tor network.

In this blog post, we set up a private root CA with mkcert on our local development machine, create a TLS certificate, and enable Spring Boot to use TLS and HTTP/2.

How to serialize and deserialize JavaScript BigInt values in JSON in a full-stack application with Spring Boot

In this blog post, we are going to create two neural networks with brain.js and Tensorflow.js, train them with the MNIST dataset, and use the trained models in a web application to detect digits.

Building a simple feedforward neural network in Java and JavaScript, training it with MNIST, and using the exported weights for browser-based digit recognition

This post shows a small Angular client and Spring Boot back end that demonstrate two Google Cloud Vision upload flows: upload through the server and upload to Cloud Storage with a pre-signed URL.

In this blog post, we combine Angular's generated service worker with custom Background Sync logic in an Ionic and Angular application.

Installing WireGuard, a simple, fast, and modern VPN, on an Amazon Lightsail virtual server and connecting an Android mobile device.

How to register a global error handler in a standalone Angular application, send reports to a back end, and queue failed reports in IndexedDB until the browser can retry them.

Converting text from a web application into speech with Google Cloud Text-to-Speech

The Beacon API lets a browser queue small POST requests without blocking navigation.

A closer look at the ES2020 numeric primitive BigInt

In this article, I show you how to self-host TileServerGL, an open-source tile server

This blog post takes a closer look at the Background Sync API, shows how to use it as a progressive enhancement, and presents an example that synchronizes data between an Ionic web application and a Spring Boot server application.

This tutorial shows how to integrate a custom Workbox service worker into an Angular application with a Vite-based build step.

In this tutorial, I present two ways to send emails from your self-hosted Linux server: relaying through a third-party SMTP provider and running a send-only Exim4 server.

How to install a backup job that runs daily and sends files to Amazon S3

In this tutorial, I show you how to self-host a Git server with Gitea

A quick introduction to the free Windows SSH client PuTTY.

Initial configuration steps after renting a new VPS server

In this blog post, I present examples that check passwords against commonly used and compromised password datasets.