Spring Boot and Vaadin CRUD Example
Build a Spring Boot and Vaadin CRUD app with a Grid, a validated form and Spring Data JPA. Complete code for every file, run steps and real screenshots.
Generate PDF from HTML Template in Java with OpenHTMLtoPDF
Generate PDF from HTML template in Java with OpenHTMLtoPDF 1.1.97, Thymeleaf or FreeMarker, plus jsoup for broken HTML, page numbers, fonts and safety.
Flogger Fluent Logging in Java: Rate Limits vs SLF4J 2
Learn Flogger fluent logging in Java with version 0.9, backends, rate limiting, lazy arguments and stack traces, compared with the SLF4J 2 fluent API.
JMeter Tutorial for Beginners: Load Test a REST API
Learn JMeter 5.6.3 step by step: build a test plan with a thread group, HTTP requests, an assertion and think time, run it in CLI mode and read the HTML report.
Java Chatbot Example: AIML with Program AB and LLM APIs
Build a Java chatbot with AIML and Program AB on Java 25, see the library status today, and add an LLM chatbot with HttpClient for many model providers.
Dozer Bean Mapping Example and Migration to MapStruct
Dozer bean mapping with Dozer 7 (XML, annotations, API, custom converters), its inactive status, and how to migrate to MapStruct or ModelMapper.
JSON.simple: Read and Write JSON in Java (and Alternatives)
JSON.simple examples to read and write JSON files in Java, its status since 2012, common pitfalls, and the same code with Jackson and Gson.
OpenCSV: Read and Write CSV Files in Java
OpenCSV 5.12 examples to read and write CSV files in Java as arrays, maps and beans, with quoting, appending, bad rows and large files explained.
Read and Write PDF in Java with iText 9 (and OpenPDF)
Read and write PDF in Java with iText 9 (text, tables, images, passwords, stamping), the AGPL license explained, and OpenPDF as an LGPL option.
Override toString() in Java: ToStringBuilder, Records, IDE
Learn to override toString in Java with ToStringBuilder from Commons Lang 3, records, Objects.toString and IDE generation, without leaking passwords.