This step‑by‑step tutorial shows how to create a functional AI development‑assistant agent using Spring Boot, LangChain4j, and LangGraph, covering environment setup, tool, state, and workflow definitions, API exposure, testing, Docker packaging, and optional enhancements.
This article explains how to design and implement a three‑level cache pyramid (Caffeine → Redis → MySQL) in Spring Boot 3, covering configuration, a reusable CacheTemplate, hot‑key handling, random TTL, warm‑up, monitoring, and load‑test results that show latency dropping from tens of milliseconds to a few milliseconds while cutting CPU and network usage dramatically.
This article provides an in‑depth analysis of Spring AI Alibaba, comparing it with Spring AI, detailing its four‑layer architecture, GraphCore workflow engine, AgentFramework, enterprise‑grade MCP integration, code examples, pros and cons, suitable scenarios, and future roadmap for Java developers building AI applications.
An online payment outage was traced to a forgotten transaction commit in a Spring service, leading to polluted connections that silently blocked subsequent orders, and the article explains the root cause, debugging steps, quick fix, and preventive measures to avoid similar bugs.
This tutorial explains OCR fundamentals, introduces Tesseract and its Java wrapper Tess4j, shows how to download language data, integrate Tess4j into a SpringBoot 3 project with Maven configuration, and provides test code for Chinese, English, and mixed‑language image recognition while highlighting performance considerations.
This tutorial walks through two Java examples—a simple Caesar‑style encryption/decryption program that shifts letters by four positions and a nested‑loop implementation of the 9×9 multiplication table—explaining the logic, code, and output step by step.
JetBrains' newly released Koog for Java provides a native Java AI Agent framework that lets developers annotate methods as tools, assemble agents with a Builder‑style API, and let large language models orchestrate multi‑step tasks without writing explicit control flow, as demonstrated with banking and e‑commerce examples.
The article reflects on Oracle's Java 26 release, contrasting the rapid evolution of the language with the stubborn reality of legacy Java 8 projects, and urges developers to rethink the "Java is old" excuse while acknowledging the practical challenges of upgrading.
After years of piling logging, caching, and security directly into Spring Boot services, the author shows how applying the Decorator pattern—implemented via dedicated @Service beans and @Primary/@Qualifier wiring—creates a clean, extensible chain that respects the Open/Closed Principle, while outlining practical steps, trade‑offs, and pitfalls.
A real‑world K8s pod hang caused by a race between Spring's shutdown paths triggered a classic deadlock in versions 7.0.0‑7.0.3, which Spring 7.0.4 resolves along with 40+ new features, performance boosts, and dozens of other bug fixes, offering concrete upgrade guidance for developers.
This tutorial explains OCR fundamentals, introduces the open‑source Tesseract engine and its Java wrapper Tess4J, shows how to download the required traineddata files, and provides step‑by‑step Spring Boot 3 integration, configuration, and test code for Chinese, English, and mixed‑language image recognition, plus important usage notes.
This tutorial explains Java's jump statements—break, continue, and the labeled break—showing their syntax, how they affect single and nested loops, and best‑practice considerations through concrete code examples and execution results.
During a holiday break the author used AI programming assistants Kiro and OpenCode to create a complete Java‑backed, Jamstack‑based full‑stack application that scrapes Epic Games' free‑game listings, generates static JSON/HTML pages, and deploys automatically to Cloudflare Pages, demonstrating AI‑driven development efficiency.
In 2026, AI has reshaped software development so that Java programmers must shift from obsessing over syntax to mastering three irreplaceable abilities—business abstraction and architecture design, AI engineering and efficiency control, and complex problem troubleshooting—to stay valuable and avoid obsolescence.
This article explains how to create and use Jar Skills in the Qoder JetBrains plugin to embed SKILL.md files inside Java JARs, extract them with the skillsjars‑maven‑plugin, and leverage these skills—along with @openFiles—to enhance AI‑assisted coding, provide best‑practice documentation, and improve code generation for internal and third‑party libraries.
This guide explains why the FIRMS Java client was created, describes the FIRMS fire data service, details the library's modular structure, shows how to obtain a MapKey, provides Spring configuration and usage examples, and includes Maven installation instructions for seamless integration into Java or Spring Boot projects.
This article explains Java's loop constructs—including while, do‑while, for, nested loops, foreach, and bubble‑sort implementations—through detailed syntax descriptions, step‑by‑step execution processes, and multiple concrete code examples with expected outputs.
The article explains why traditional Cron‑based scheduling fails under high load, walks through three architectural stages—from database polling to Redis delay queues and finally a full distributed scheduler—showing code examples, design trade‑offs, and performance numbers that enable thousands of tasks per second.
When a midnight CPU alarm threatened a core Java service, I raced through system checks, JVM profiling, algorithm refactoring, database indexing, Docker isolation, and Prometheus alerts, ultimately restoring performance and highlighting the importance of proactive monitoring and technical debt management.
This tutorial walks through the fundamentals of OCR, explains how to download the required Tesseract traineddata files, shows how to add Tess4j as a Maven dependency, configure SpringBoot with custom properties, and provides complete Java test code for Chinese, English, and mixed‑language image recognition, highlighting performance considerations and file‑naming requirements.
This tutorial walks through Java's selection structures—including if, if‑else, if‑else‑if, nested if, and switch—detailing their syntax, execution flow, example code, output results, and key differences, helping beginners write correct and portable conditional logic.
This comprehensive guide walks you through why Jackson annotation tweaks are essential, presents a full annotation hierarchy, demonstrates over 25 core annotations with concrete code examples, covers polymorphic handling, special scenarios, global Spring Boot 3 configuration, production best practices, common pitfalls, performance tips, an end‑to‑end e‑commerce example, and testing strategies, all aimed at mastering JSON serialization in Spring Boot.
This guide explains why hot‑reloading Java code is essential for large Spring Boot projects, compares three approaches—Spring Boot DevTools, IntelliJ IDEA's built‑in HotSwap, and the JRebel plugin—and provides step‑by‑step installation and usage instructions for each method.
The article warns that within half a year AI-driven code generation will slash demand for standard Java CRUD developers, causing massive layoffs, a shift in hiring criteria, and forcing programmers to acquire AI and domain expertise to stay employable.
The article outlines JVM tuning fundamentals, categorizing common issues, presenting six optimization principles, detailing key JVM parameters, and introducing the jps command‑line tool to help developers diagnose and improve Java application performance while maintaining stability.
The article explains the JVM's core components, execution workflow, garbage collection fundamentals—including GC roots and Stop-The-World pauses—and introduces basic tuning tools like VisualVM and Arthas, helping readers grasp where performance optimizations should focus.
This tutorial walks through Java 2D arrays, covering their definition, variable declaration syntax, creation with the new keyword, direct initialization, element access, and modification, illustrated with code examples and visual tables.
This article breaks down the Claude Code architecture into 12 progressive stages, explains the core agent loop in Python and Java, details each capability layer with code snippets, and provides a quick‑start guide—including environment setup, test runs, and a visual web platform—to help developers replicate the AI programming agent from scratch.
The article explains how Java’s six‑month release cadence has led to JDK 26’s major upgrades—including HTTP/3, Structured Concurrency, stronger final‑field immutability, AOT object caching, G1 GC enhancements, Lazy Constants, pattern‑matching extensions, Vector API and PEM support—showing the performance, latency and security gains developers can unlock by moving beyond Java 8.
Spring Boot follows the "Convention over Configuration" principle, yet most projects keep 80% of the configuration redundant; this article walks through 13 zero‑configuration features—from embedded servers and auto‑configured data sources to Actuator monitoring and multi‑environment profiles—showing concrete code examples, default values, and production‑grade tweaks that let developers dramatically reduce configuration files and write cleaner Java back‑ends.
The article examines Spring Framework 7’s architecture-level changes, including Jakarta EE 11 baseline, Kotlin 2.2 support, module refactoring, the new @HttpExchange client, built-in API versioning, startup and WebFlux performance gains, native image enhancements, and provides a step-by-step migration checklist for Java developers.
The article dissects Spring 7.0.4’s critical deadlock bug, explains several other subtle fixes, details three major performance optimizations that can cut startup time by up to 50 % and up to 20 % request latency, and provides practical upgrade guidance for Kubernetes‑deployed Java services.
This guide shows how to display a custom ASCII art logo in the console by adding a banner.txt file to the resources folder and using Spring Boot's built‑in variables such as ${AnsiColor} and ${spring-boot.version} to customize the appearance.
Facing slow page loads in a legacy WAF reporting system, we dissected a 1000‑line Java method, introduced hourly aggregation, Redis auto‑increment counters, and scheduled synchronization, eliminating costly SQL scans and achieving sub‑second queries on 1.5 million logs, while outlining remaining optimization opportunities.
This tutorial walks through the fundamentals of Java one-dimensional arrays, covering declaration syntax, memory allocation with new, default values, direct initialization, element access, out‑of‑bounds handling, and element modification with concrete code examples and expected outputs.
This article analyzes the evolution of enterprise AI from single‑model chat to scalable multi‑agent workflows, explains seven core multi‑agent patterns—including Pipeline, Routing, Skills, Subagents, Supervisor, Handoffs, and Custom Workflow—provides detailed implementation guidance with Java code, and shows how Spring AI Alibaba now natively supports AgentScope orchestration for robust, observable AI applications.
The article explains how Spring AI's AskUserQuestionTool brings an interview‑style questioning model to Java, letting AI clarify ambiguous requirements before generating code, and provides step‑by‑step implementation details, code samples, and a walkthrough of the underlying tool architecture.
Most teams treat REST APIs as merely functional, leading to chaotic naming, frequent breaking changes, rising front‑end costs, and JVM pressure; this article re‑examines REST’s constraint‑based architecture and presents concrete Java‑centric design principles, best‑practice guidelines, and implementation examples to build sustainable, evolvable APIs.
JDK 26, released on March 17, 2026, introduces structured concurrency, native HTTP/3, primitive‑type pattern matching, lazy constants, G1 GC sync improvements, AOT object caching, final‑field reflection limits and post‑quantum encryption, delivering up to 30% performance gains, 40% thread‑utilisation, and up to 70% code‑size reduction without requiring code changes or new dependencies.
This article explains how the new quarkus‑langchain4j 0.1 extension lets developers embed LLMs into Quarkus applications using a declarative @RegisterAiService API, with support for tools, document stores, RAG, and full code examples.
The article explains how poorly designed prompts cause AI agents to invoke unnecessary or incorrect tools, and shows how a structured prompt template combined with the Model Context Protocol (MCP) and three safety measures can raise tool‑calling accuracy from about 30% to over 95%.
This guide demonstrates how JetBrains IDE users can integrate the Qoder AI plugin to accelerate backend development, covering installation, configuration, performance tuning of deep‑pagination queries, and safe incremental refactoring of legacy Java code with detailed code examples and results.
This article chronicles the rise and fall of Java Applets from their 1995 debut, through their golden era and technical limitations, to their eventual removal from browsers and the JDK, and shows how WebAssembly inherits the original vision of high‑performance compiled code in the browser.
This article explains why adding Redis alone may still be slow, introduces a three‑level cache pyramid (Caffeine L1, Redis L2, DB L3) built with Spring Boot 3, and provides complete configuration, code, warm‑up, monitoring, and benchmark results that reduce response time from 28 ms to 2 ms while cutting CPU usage by 35%.
This article introduces Spring Explyt, a free open‑source IntelliJ IDEA Community plugin that adds full Spring development features—including accurate bean detection, advanced code completion, endpoint management, built‑in HTTP client, and enhanced debugging—by using a lightweight runtime analysis, and provides installation, usage steps, and a feature comparison with IDEA Ultimate.
The article explains how to replace the blunt kill -9 command with a coordinated graceful shutdown process for Spring Cloud microservices, covering signal handling, Eureka cache nuances, actuator endpoints, Spring Boot 2.3 settings, custom shutdown endpoints, and strategies for Kafka, scheduled jobs, thread pools, and long‑running loops.
This note explains why Java introduces arrays, defines arrays as collections of same‑type variables, demonstrates the limitation of using individual variables for many items, and outlines six key characteristics of Java arrays, including fixed length, zero‑based indexing, and default values.
This technical guide walks developers through six HTTP API authentication techniques—None, Basic, Bearer Token, API Key, HMAC signature, and Open‑Platform hybrid—providing Java code samples, sequence diagrams, usage scenarios, and security best practices for each method.
A production outage caused by OutOfMemoryError revealed that millions of duplicate String objects—originating from HTTP headers, JSON keys, and other common fields—were silently inflating heap usage, and the article shows how to diagnose, optimize, and prevent such hidden String-related memory problems in Java applications.
The article analyzes how JDK 21 and JDK 22 dramatically improve language ergonomics, performance, and ecosystem compatibility over JDK 8, providing concrete code examples, benchmark data, and a three‑step migration plan for Java developers facing high‑concurrency and large‑memory workloads.
Oracle announced the GA release of Java 26/JDK 26, detailing ten JEP‑driven enhancements, additional low‑level improvements, expanded security measures, updated Unicode support, JVM performance tweaks, and the introduction of the Oracle Java Verified Portfolio that now covers JavaFX, Helidon and VS Code extensions.
This article introduces Hutool, a comprehensive Java utility library, outlines its main modules such as SecureUtil, HtmlUtil, and CronUtil, provides code snippets for common tasks like password hashing, HTML escaping, and scheduling, and shares practical tips for integrating these tools into applications.
This guide introduces Spring Explyt, an open‑source IntelliJ IDEA Community plugin that brings full‑featured Spring support—including precise bean detection, advanced code completion, endpoint tools, and built‑in HTTP client—to the free IDE, with installation steps, usage tips, and a feature comparison.
This guide explains Zipkin’s core components—Collector, Storage, RESTful API, and Web UI—then walks through downloading the executable jar, placing it on a Linux server, creating start and stop shell scripts with proper permissions, and finally launching the Zipkin server and accessing its web interface.
This article explores the Learn Claude Code website, breaking down the universal agent loop into twelve incremental versions, demonstrating language‑agnostic implementations in Python and Java, and detailing progressive capabilities—from basic tool integration to memory compression, concurrency, and multi‑agent collaboration.
This article provides a comprehensive walkthrough of Java's operators and expressions, covering arithmetic, assignment, increment/decrement, relational, logical, bitwise, and ternary operators, their syntax, evaluation rules, precedence, and practical code examples to help beginners master Java fundamentals.
This guide explains why Spring MVC can read the request body only once and provides a custom solution using a RepeatReadBodyMethodProcessor and RepeatBodyHttpRequest to enable multiple @RequestBody parameters in Spring Boot 3.5.0.
The article analyzes how AI is now writing code, compressing development cycles from half a day to minutes, reshaping programmer roles through three historical value shifts, highlighting new AI‑centric responsibilities, and offering a concrete learning path for Java developers to thrive in the AI era.
A newcomer replaced MyBatis with MyBatis‑Plus in an old MySQL‑based project, encountered a "Conversion not supported for type java.time.LocalDateTime" error, traced it to MyBatis 3.5.1 dropping built‑in type handling and an outdated mysql‑connector‑java driver, and resolved it by upgrading the driver while also fixing a related validation bug that caused production failures.
This article explores the challenges of sudden traffic spikes that overload applications and databases, and presents a step‑by‑step design, implementation, and optimization of a MyBatis plugin that intercepts SQL, applies fingerprint‑based rate limiting, and integrates with Joycode for rapid development and testing.
This comprehensive guide explains the purpose, configuration attributes, and practical usage of Spring MVC request‑mapping annotations, Spring dependency‑injection annotations, scope settings, and conditional annotations, providing code snippets and visual examples for each feature.
Spring Framework 7.0.4 resolves a rare deadlock caused by concurrent shutdown paths in Kubernetes, introduces dozens of bug fixes and performance tweaks—including faster request routing, annotation caching, and validation refactoring—that together can cut startup time by 30‑50% depending on the JDK version.
The article explains Spring’s event-driven model, detailing how ApplicationEventPublisher, ApplicationListener, and ApplicationEventMulticaster work together to publish, multicast, and handle events, and provides code examples for defining custom events, implementing listeners via interfaces or @EventListener annotations, and configuring asynchronous handling.
This article explains how Java's BigDecimal class provides exact arithmetic for numbers beyond double's 16‑digit limit, demonstrates the pitfalls of using the double constructor with concrete examples, and guides developers through constructors, common methods, formatting, exception handling, and a utility class for high‑precision calculations.
This article explains Java's primitive data types—including integer, floating‑point, character, and boolean types—covers their memory sizes, value ranges, literal syntax, automatic and explicit type conversions, and provides concrete code examples and tables for reference.
The article explains how overusing Optional, Stream, and Lambda in high‑frequency Java code creates hidden costs such as excessive object allocation, GC pressure, and cache‑line disruption, and shows a more efficient loop‑based alternative with profiling evidence and practical guidelines.
This guide explains the default Java ThreadPoolExecutor workflow, identifies why interview questions may require launching maximum threads before queuing tasks, and presents a concise two‑pool plus custom rejection‑policy solution that satisfies the requirement without writing a custom thread pool from scratch.
This guide outlines interview focus points, core definitions, and deep analysis of Cookie, Session, and Token (JWT), compares their storage, security, scalability, and cross‑origin support, and provides high‑frequency follow‑up questions, common variants, memory mnemonics, and selection principles for Java authentication.
The article explains that Java's synchronized keyword guarantees mutual exclusion but cannot stop the CPU or compiler from reordering instructions inside the critical section, leading to a broken double‑checked locking pattern unless the instance field is declared volatile.
This article details Lalamove's 2025 "Big Cleanup" initiative that identified and removed over 30% of dead Java code and more than 100 obsolete DB fields, describing the tools, SA plugin, BigClean scanner, MyBatis interceptor, and quality‑assurance strategies used to ensure safe, efficient code slimming.
This note introduces Java constants and variables, covering their definitions, naming conventions, declaration syntax, initialization rules, multiple declarations, and how constants differ from mutable variables through concrete code examples.
This article analyzes the evolution of AI agents, compares multi‑agent and single‑agent frameworks, introduces the concept of an AI Tool Platform, and presents a five‑layer enterprise AI architecture with a step‑by‑step Java implementation roadmap for real‑world automation.
The article explains why traditional OS‑based thread pools choke under 100,000 concurrent Java requests, introduces Java 21's Virtual Threads from Project Loom, shows their low‑memory, high‑throughput characteristics, provides Spring Boot configuration and code samples, and warns about synchronization, ThreadLocal and CPU‑bound pitfalls.
This article compares Spring's BeanFactory and ApplicationContext, detailing their roles, loading strategies, feature sets, code examples, and recommended usage scenarios, helping developers choose the appropriate container for their projects.
This note explains Java identifiers—allowed characters, first‑character rules, valid and invalid examples—lists all language keywords that cannot be reused as names, and outlines practical naming conventions for classes, methods, constants, and packages to improve code readability.
This article systematically explains the full set of Spring Security annotations—including @EnableWebSecurity, @EnableMethodSecurity, @Secured, @PreAuthorize, @PostAuthorize, and @RolesAllowed—showing how they work, their differences, and how to apply them in a practical Spring Boot project.
This guide walks through a complete Java implementation for Alipay's periodic (cycle) payment service, covering business prerequisites, Spring Boot configuration, signing and deduction APIs, callback verification, retry mechanisms, scheduled tasks, and reconciliation, with production‑grade code examples.
This tutorial walks you through installing the JDK, creating a HelloJava.java source file with Notepad, compiling it using javac, running it with the java interpreter, and explains the basic structure, comments, class definition, and main method of a Java program.
Spring Data AOT (Ahead‑of‑Time) repositories move reflection, method‑name parsing, JPQL generation and proxy creation from runtime to build time, dramatically speeding up Spring Boot 4 application startup, reducing memory usage, and surfacing configuration errors early in the compilation phase.
JEnv tackles the long‑standing pain of juggling multiple Java versions by delivering sub‑second scanning (400 ms on a full‑depth scan), a concurrent Dispatcher‑Worker engine, smart pre‑filtering, cross‑platform support, themed terminals, real‑time statistics, and a modular architecture, all demonstrated with concrete benchmarks and usage scenarios.
This guide walks through installing the JDK, configuring JAVA_HOME, PATH and CLASSPATH on Windows, and verifying the setup, showing that only the JDK and a basic text editor are needed to write and run your first Java program.
The article explains how the Builder pattern in Spring Boot eliminates the telescoping‑constructor and unsafe‑setter problems of complex objects, improves readability, immutability and maintainability, shows hand‑written and Lombok implementations, provides usage examples for DTOs, API responses and queries, and offers best‑practice guidelines.
The article explains how Redis guarantees atomic operations through single‑command atomicity, MULTI/EXEC transactions, and the WATCH optimistic‑lock mechanism, providing Java/Jedis code examples and discussing their role in ensuring data consistency in distributed systems.
The article explains how Java source files are compiled into bytecode, run on the JVM across Windows, Linux, macOS, and Solaris, and describes the two parts of the Java platform—the virtual machine and the API—highlighting why Java’s “write once, run anywhere” model suits distributed, object‑oriented development.
This article outlines Java’s origin, its cross‑platform “write once, run anywhere” feature, the evolution of its SE, EE, and ME editions, and the key advantages that make Java a preferred language for desktop, web, enterprise, and embedded development.
Spring AI eliminates SDK fragmentation, side‑car Python services, and operational complexity by providing a unified AI abstraction layer for Java, enabling seamless model switching, RAG, tool calling, and offering concrete performance data and best‑practice guidance for production use.
The article analyzes Java's enduring dominance in enterprise software by examining its cross‑platform runtime, extensive ecosystem, continuous language and runtime innovations, performance and security breakthroughs, and the resulting cost, stability, and talent advantages that keep 90% of Fortune 500 companies invested.
This article explains the Chain of Responsibility design pattern, shows classic Java implementations, demonstrates its use in Spring Security, provides real‑world examples such as order processing, logging pipelines, and approval workflows, and offers advanced functional and asynchronous techniques along with performance tips and common pitfalls.
When the core pool size of a Java ThreadPoolExecutor is configured to zero, new tasks are initially placed into the work queue, and the executor may create non‑core threads to process them, a behavior that often surprises interview candidates.
This article explains the concepts, characteristics, default states, and usage patterns of MyBatis first‑level (SqlSession) and second‑level (Mapper) caches, provides Java code demos for each, and compares their scope, lifecycle, consistency, and suitable scenarios.
This guide explains how to add MFA to a Spring Boot 3 application using password plus one‑time token authentication, covering the theory of MFA factors, required dependencies, API definitions, security configuration, token‑generation handling, custom login pages, and the complete verification flow with code snippets and screenshots.
This article explains the MyBatis plugin mechanism, walks through implementing the Interceptor interface, configuring the plugin in mybatis-config.xml, provides a complete code example, and outlines common use cases such as SQL logging, performance monitoring, permission control, and automatic field filling.
This guide walks through the end-to-end setup of a WeChat public-account keyword auto-reply, covering the message flow, required server configuration in the WeChat console, and Java servlet implementations for the GET verification and POST message-handling endpoints.
After a system has been running, developers often drown in manual log statements to answer questions like why an interface is slow, who called a method, or what parameters were passed, but Spring Boot AOP lets you replace all that with a single annotation and aspect that automatically records calls, execution time, parameters, exceptions, and call chains, keeping business code clean.
This guide explains what an AI Agent is, outlines its four core abilities, compares it with traditional programs, presents a layered architecture diagram, shows common use‑case scenarios, and provides step‑by‑step Java code using LangChain4j to build basic, multi‑tool, planning, reflective, and collaborative agents together with optimization tips and FAQs.
This article provides a step‑by‑step guide to quickly set up LangChain4j, configure API keys, call LLM models, use structured outputs, function calling, and chat memory, and demonstrates three hands‑on projects—smart assistant, document summarizer, and code generator—plus FAQs and resources.
This guide explains how to load files in Spring Boot 3 using the Resource abstraction, covering classpath, filesystem, and URL prefixes, @Value injection, direct Resource instantiation, dynamic loading with ResourceLoader, and bulk loading with ResourcePatternResolver, plus common pitfalls and best‑practice code examples.
When @Data and @Builder are used together on a Lombok‑annotated class, the generated code can lose getters, setters, and the no‑argument constructor, leading to compilation failures; the article explains the cause and shows how to fix it with @NoArgsConstructor and @RequiredArgsConstructor.
The article compares LangChain4j and Spring AI across design philosophy, core features, ecosystem integration, community maturity, and learning curve, providing concrete code examples, a feature‑richness matrix, and practical selection guidelines to help Java developers choose the most suitable AI framework for their needs.
AgentScope Java, Alibaba's open‑source multi‑agent framework, lets Java developers build autonomous assistants and collaborative agents with built‑in ReAct reasoning, RAG, memory, and enterprise‑grade integrations, offering a compelling alternative to Python‑centric AI stacks and Spring AI Alibaba.
