Former senior programmer at a Fortune Global 500 company, dedicated to sharing Java expertise. Visit Feng's site: Java Knowledge Sharing, www.java1234.com
Flowable is an open‑source Java workflow engine that follows the BPMN 2.0 standard, offering tighter Spring Boot integration, full CMMN/DMN support, better performance than Activiti, and flexible deployment options, with detailed comparisons to Activiti and Camunda and step‑by‑step Spring Boot and standalone examples.
The article explains why Spring Boot continues to use Jackson as its default JSON serializer, detailing the automatic ObjectMapper/JsonMapper creation, the HTTP message conversion process, Jackson’s balanced strengths, practical code samples, and how to switch to alternatives like Gson, JSON‑B, or Fastjson2.
The article explains how Apache Tika, an open‑source content analysis toolkit, lets developers detect file types, extract text and metadata from over a thousand formats, and integrate the functionality via a simple CLI, a RESTful server, or direct Java APIs, making it ideal for search, archiving, content moderation, and AI‑driven knowledge bases.
CodeGraph builds a local knowledge graph of a codebase, letting AI assistants query a SQLite index instead of grepping files, which cuts tool calls by up to 89%, reduces token usage by around 70%, and keeps all code private, explaining its rapid rise in popularity.
Apache PDFBox, an open‑source Java library under the Apache 2.0 license, lets developers create, read, modify, and extract data from PDFs, offering extensive features, command‑line tools, and seamless Maven integration, which explains its growing adoption in Java‑based backend and enterprise projects.
Spring 7 doesn’t remove Feign from the classpath but officially discourages its use, labeling OpenFeign as feature‑complete and recommending the new Spring Framework HTTP Service Client, with a detailed comparison, migration steps, and guidance on when Feign may still be viable.
FastCode, an open‑source framework from HKU’s DS team, builds semantic maps and structural graphs of codebases to let AI assistants answer queries up to four times faster, cut token usage by up to 44 %, and achieve higher accuracy across benchmarks, supporting multiple languages and deployment options.
The article explains why floating‑point types are unsafe for monetary values, compares the Long‑in‑cents and BigDecimal‑in‑yuan approaches, lists their advantages and drawbacks, and provides concrete Java code, database schemas, layer‑boundary conversion patterns, and common pitfalls.
Quarkus, Red Hat's cloud‑native Java framework, achieves dramatically faster startup (0.3‑1 s vs 2‑5 s) and roughly half the memory usage (150‑200 MB vs 300‑500 MB) by moving many optimizations to compile time, and offers a Spring‑like developer experience with extensions, reactive support, and hot‑reload tooling.
The article explains that OpenJDK is the open‑source reference implementation while Oracle JDK is Oracle’s distribution built on it, outlines their minimal functional differences after Java 11, compares licensing, update policies and commercial support, shows how to identify the installed JDK, and offers practical selection guidance for students, enterprises and production environments.
