This article walks through defining a simple Calculator interface, provides two implementation styles, and demonstrates both reflection‑based and annotation‑based hot‑deployment of uploaded JARs in a Spring application, including bean registration, removal, and a test loop.
Meta has spent four and a half years building a custom, six‑stage Kotlinator pipeline to automatically translate its massive Android Java codebase to Kotlin, tackling null‑safety, build‑time, and headless J2K challenges, and now reports that only half the work is complete while the hardest problems remain.
This article walks through the motivation, architecture, installation steps, core concepts, and practical usage of integrating the URule visual rule engine into a Spring Boot project, including library files, wizard and script rule sets, decision tables, and a real‑world promotion scenario.
The article defines Java thread deadlock, illustrates five typical deadlock patterns with diagrams, shows how they cause threads to wait indefinitely, and presents five practical solutions—including consistent lock ordering, reducing nested locks, shrinking lock scope, using timed locks, and adopting lock‑free designs.
Spring Boot 4.1 introduces 20 major updates, including removal of deprecated APIs, new gRPC support, enhanced Jackson configuration, improved observability with OpenTelemetry, SSL for RabbitMQ streams, lazy JDBC connections, and numerous Gradle and Maven plugin enhancements, while providing detailed migration guidance for developers.
The article shows how duplicating 20‑40 lines of request‑building code for each low‑code table operation leads to maintenance risk, and demonstrates extracting two generic Java methods that encapsulate invariant logic while parameterising fields, tables, and apps, dramatically reducing code and clarifying responsibilities.
This article explains what Java lambda expressions are, why they were added in Java 8, their syntax and classification, how they relate to functional interfaces, and demonstrates practical examples including anonymous inner‑class refactoring, stream usage, method references, and custom functional interfaces.
The article reviews the seven Java 8 Map convenience APIs—getOrDefault, putIfAbsent, computeIfAbsent, computeIfPresent, compute, merge, and forEach—plus replaceAll and Map.of, showing concise code examples, best‑practice recommendations, concurrency considerations, and common pitfalls for modern Java developers.
Most developers give AI coding tools vague one‑sentence requests for Spring Boot tasks, causing the AI to generate code that violates project conventions, while a detailed engineering task sheet that includes context, constraints, and verification steps dramatically improves the quality and safety of the generated code.
This article details how to design and tune a Netty‑based single‑machine gateway capable of handling one million concurrent TCP long‑connections, covering network model, memory management, protocol design, OS and JVM optimizations, clustering, load balancing, graceful shutdown, monitoring, and practical deployment considerations.
The article explains why RocketMQ inevitably delivers duplicate messages under at‑least‑once semantics, analyzes root causes in producer, broker and consumer stages, and presents a production‑grade idempotent solution that combines business keys, Redis caching, Redisson locks, a MySQL idempotent table, AOP interception, and comprehensive monitoring to guarantee exactly‑once business outcomes even under high concurrency and Kubernetes graceful shutdown.
The article explains how Java 8 added default and static methods to interfaces—allowing method bodies, enabling backward‑compatible extensions, illustrating usage with code examples, handling multiple‑interface conflicts, and introducing Java 9 private methods, while summarizing common pitfalls and best‑practice guidelines.
The article explains how tangled if‑else branches in a business middle‑platform can be replaced by a flow‑engine and plugin‑extension approach, using the open‑source MemberClub project to demonstrate configuration, node definition, and execution mechanics that improve code isolation and extensibility.
This article explains how Spring Boot’s plugin architecture—using SPI, custom configuration, and Spring Factories—enables modular, extensible services, demonstrates step‑by‑step implementations with code samples, and shows real‑world use cases for building flexible micro‑service components.
The article explains five concrete agent‑orchestration patterns—Chain, Routing, Parallelization, Orchestrator‑Workers, and Evaluator‑Optimizer—showing how to combine Spring AI's ChatClient with simple Java control flow to transform single‑turn interactions into controlled, multi‑step decision workflows, complete with code examples and guidance on when to use each pattern.
This article explains how the Model Context Protocol (MCP) standardizes AI model access to external tools like file systems, databases, and browsers, showing how to integrate ready‑made MCP servers with Spring AI, expose your own tools as MCP servers, and choose between stdio and SSE transports.
The article compares two Java‑based integration methods for sending pure‑text documents to RagFlow—first uploading an empty placeholder file then adding chunks, and later writing the text to a temporary file and uploading it directly—detailing implementation, pitfalls, and why the latter is preferred.
This article compiles a curated list of 20 widely used Java libraries—covering logging, JSON processing, testing, utilities, HTTP, XML, Excel, bytecode manipulation, connection pooling, messaging, PDF, date‑time, collections, email, HTML parsing, cryptography, embedded databases, JDBC debugging, serialization, and networking—to help developers avoid reinventing the wheel and boost productivity.
This article walks Java developers through using Spring AI to build AI agents, comparing it with Python's LangChain, detailing architecture, environment setup, prompt templates, tool integration, RAG implementation, production‑grade features, and a side‑by‑side feature comparison.
This article explains how Spring AI's Tool Calling lets large language models overcome their inability to access real‑time or private data by invoking annotated Java methods, showing step‑by‑step code examples, parameter handling, and the execution flow that bridges model requests with actual method results.
The article explains why simultaneous Excel exports can overload a server, proposes a fixed‑size FIFO queue to serialize export tasks, and provides a complete Spring‑Boot implementation—including the ExportQueue, abstract export logic with EasyExcel, and a test controller—to demonstrate the queuing mechanism in action.
Although Spring Boot remains the most used Java framework (14.7% of developers per Stack Overflow) its mindshare dropped from 40.3% to 29.2%, prompting a shift from learning how to write code to learning how to review AI‑generated Spring Boot projects.
This guide walks through integrating EasyExcel with Spring Boot, covering Maven setup, entity definition, utility class creation, basic and advanced export scenarios such as complex headers, cell merging, custom formatting, and large‑scale paging, plus common pitfalls like dependency conflicts and annotation misuse.
The article examines the limitations of a naïve QuestionAnswerAdvisor RAG implementation, introduces Spring AI's RetrievalAugmentationAdvisor for modular RAG, and demonstrates how query rewriting, multi‑turn compression, and an empty‑context augmenter improve recall and prevent model refusals.
This article explains why traditional keyword search fails on synonyms, introduces Spring AI's local ONNX‑based EmbeddingModel to convert text into high‑dimensional vectors, shows how to store and query those vectors with SimpleVectorStore, and compares production‑grade vector store options.
The article explains that Spring's second‑level cache can resolve simple circular dependencies, but a third‑level cache is introduced to handle cases involving AOP proxies, allowing delayed proxy creation without breaking the bean lifecycle.
The article breaks down a complete Dubbo RPC invocation into ten precise steps—five on the consumer side and five on the provider side—explaining each core component such as Proxy, Filter, Cluster, LoadBalance, Protocol, and Transport, and addresses common interview follow‑up questions about clustering, load balancing, and sync vs async calls.
This article lists ten common IntelliJ IDEA pitfalls—from high CPU usage and Lombok errors to Maven download slowness and Git commit issues—and provides step‑by‑step configurations, memory tweaks, plugin settings, and .gitignore rules to make the IDE run smoothly for Java developers.
This article explains how developers can bypass token‑cost barriers by using iFlytek’s MaaS platform to obtain free, unlimited‑token access to the Qwen 3.6‑35B‑A3B model, details the model’s MoE architecture and benchmark performance, and provides a complete Java integration tutorial with code samples and practical use‑case suggestions.
An online education platform needs to batch‑download course materials from self‑hosted courses, partner APIs, and archived PDFs; the article details a Spring Boot service that aggregates URLs, signs them, distinguishes direct downloads, submits an asynchronous PDF conversion and ZIP packaging task via Feign, and returns a task ID for front‑end polling.
The article walks through calculating the required QPS for 10 million SMS in an hour, derives a precise ThreadPoolExecutor configuration (core 200, max 500, queue 5000, 60 s keep‑alive, CallerRunsPolicy), and provides complete Spring Boot code with production tips such as pagination, retry, idempotency and rate‑limiting.
The article evaluates 13 Java web frameworks across six objective dimensions—performance, ecosystem maturity, learning curve, development efficiency, enterprise adoption, and innovation—ranking them into five tiers and providing concrete data such as usage statistics, startup times, and memory footprints.
This article compares Spring AI 2.0 and LangChain4j for integrating large language models into Java enterprise applications, examining their positioning, version alignment, programming models, RAG capabilities, tooling, observability, learning curves, and suitability for different team stacks to help you make an informed selection.
This article explains the three Java constant pools—class file, runtime, and string—detailing their evolution from compilation to execution, their memory locations across JDK versions, how string literals are interned, code examples illustrating their behavior, common misconceptions, and typical interview follow‑up questions.
The article explains the contract between equals and hashCode in Java, shows what goes wrong when only one is overridden, demonstrates the correct implementation with Objects.equals and Objects.hash, covers IDE/Lombok generation, JPA entity nuances, inheritance pitfalls, records, and common anti‑patterns.
This article walks through three common data‑masking approaches—SQL queries using string functions, a Java‑based "sensitive‑plus" plugin, and the mybatis‑mate‑sensitive‑jackson extension—showing configuration, code examples, and how each method masks phone numbers, ID cards and other personal fields.
The article catalogs six production‑ready pitfalls of MyBatis‑Plus—duplicate Snowflake IDs, batch‑insert disorder, enum storage errors, camel‑case mismatches, auto‑fill failures, and JSON field loss—explains their root causes with concrete examples and code, and provides practical solutions to keep the framework reliable in high‑concurrency environments.
The article explains why sending messages before a Spring transaction commits can cause data inconsistency, and demonstrates how to reliably execute asynchronous actions such as MQ notifications after a successful commit using TransactionSynchronization, custom collectors, and @TransactionalEventListener, while highlighting common pitfalls and mitigation strategies.
This tutorial explains Java 16’s record feature—a concise way to define immutable data carriers—by comparing it with traditional classes, showing the boilerplate it eliminates, detailing the automatically generated methods, providing hands‑on code examples, and outlining important usage considerations.
Java's String class is immutable and stored in a constant pool; the article explains the difference between == and equals, demonstrates common methods for inspection, transformation, splitting, and conversion, and shows best practices for concatenation with StringBuilder, thread‑safe StringBuffer, and newer utilities like join, repeat, format, and text blocks.
The article explains a structured business‑trace logging pattern that records each critical step of a workflow as a node, stores logs in a dedicated MySQL database, aggregates them by a business number, and presents them in a sortable, color‑coded front‑end for both developers and business users.
This article explains unit testing fundamentals, compares unit and integration tests, introduces Mockito's core annotations and APIs, walks through a full order‑resend example with detailed test cases, and covers best‑practice methodologies, advanced techniques, common pitfalls, naming conventions, and how to run the tests.
This article explains why large language models are powerful yet limited, defines AI agents as autonomous systems that combine a model, memory, tools, and actions, details the ReAct reasoning‑and‑acting loop, provides a 30‑line Python LangChain example and a Java Spring AI implementation, and outlines five practical use‑case scenarios and the roadmap for the series.
This article explains Spring AI Advisors as interceptors that can modify requests and responses in the LLM call chain, demonstrates building a custom logging Advisor with code examples, shows how ordering controls execution, and reviews the built‑in Advisors for memory, RAG, logging, and safety.
This article explains how Spring AI’s Media API lets a ChatClient handle both textual prompts and image inputs, shows code examples for attaching images, discusses required visual models, and outlines practical use cases such as OCR, chart analysis, and image moderation.
The article explains how Spring AI’s .entity() method lets developers obtain structured Java objects such as POJOs, lists, enums, and response entities directly from LLM outputs, eliminating the need for manual JSON parsing and handling generic‑type issues with ParameterizedTypeReference.
This article explains Java’s three fundamental object‑oriented concepts—encapsulation, inheritance, and polymorphism—by defining each principle, showing concrete code examples, outlining key language keywords, and highlighting common pitfalls for beginners.
The article explains the functional and architectural differences between Spring Cloud LoadBalancer and Netflix Ribbon, why Ribbon entered maintenance mode and was replaced, outlines migration steps, compares configuration, caching, reactive support, and provides code examples and common interview questions for Java developers.
The article explains how to move beyond static prompts in Spring AI by using System and User message roles, PromptTemplate placeholders with .param(), defaultSystem configuration for reusable role definitions, and independent PromptTemplate usage, providing concrete code examples for each technique.
This article explains how Spring AI's ChatClient serves as a high‑level façade over ChatModel, compares the synchronous call() method with the streaming stream() method, demonstrates retrieving plain text, full responses, or structured entities, and shows how to override model parameters such as temperature on a per‑request basis.
The article explains how to achieve zero‑downtime code updates for SpringBoot applications by detecting port usage, launching a new instance on an alternate port, swapping the servlet container back to the original port, and terminating the old process, with a complete code example and a live demo showing sub‑second interruption.
This article explains why a RocketMQ producer is more than a simple send API, detailing its role in system throughput, consistency and fault isolation, and walks through sending principles, thread models, high‑concurrency design, retry strategies, back‑pressure mechanisms, outbox integration and production‑grade monitoring.
This article introduces Spring AI 2.0, explains why Java developers should adopt it, and walks through setting up a Spring Boot 3.x project with JDK 17, adding the DeepSeek starter, configuring properties, writing a simple ChatController, and running a curl request to see the model’s reply.
The article explains how an e‑commerce platform’s settlement module can use the Strategy pattern to cleanly handle varied fee calculations for group‑buy, flash‑sale, special‑price and full‑discount promotions, avoiding tangled if‑else logic and simplifying future extensions.
This article walks through five proven Java 21 concurrency tuning techniques—including non‑blocking CompletableFuture pipelines, StampedLock for read‑heavy workloads, bounded queues with CallerRunsPolicy, atomic computeIfAbsent usage in ConcurrentHashMap, and correct virtual‑thread patterns—showing how each can dramatically improve throughput and stability in high‑load systems.
This guide curates essential AI Agent Skills for the Java ecosystem, covering backend tools like Spring Boot, MyBatis‑Plus, and Redis, frontend frameworks such as Vue and React, installation commands, custom Skill examples, and recommended full‑stack workflows to boost project productivity.
The article explains how an Extension‑Point mechanism can cleanly isolate tenant‑specific logic in SaaS systems by defining variation interfaces, providing per‑tenant implementations annotated with @Extension, and routing calls at runtime using hierarchical bizCode matching, avoiding tangled if‑else or inheritance explosion.
AgentScope Java 2.0 introduces distributed session handling, multi‑tenant isolation, an abstract filesystem, robust model fallback, structured context management, event streaming, a permission system, and middleware hooks, providing a cloud‑native, enterprise‑ready platform for building stable, long‑running AI agents.
The article explains how to update a Spring Boot application without stopping the service by letting two processes share the same port, detailing the underlying Tomcat and ServletContainerInitializer mechanisms, the step‑by‑step implementation, and a demo that shows sub‑second downtime during hot swaps.
MyBatisPlus Pro extends MyBatisPlus by providing a BaseController that auto‑generates CRUD, pagination, and conditional queries, dramatically cutting repetitive code; the article walks through its architecture, quick‑start steps, deep technical mechanisms, pros and cons, and practical usage guidelines.
The article explains how layered caching in Java back‑ends—combining MyBatis first‑ and second‑level caches with a service‑layer Caffeine + Redis cache—affects cache granularity, consistency, distribution, and performance, and provides concrete configuration examples, code snippets, and best‑practice guidelines.
This tutorial demonstrates how to integrate Spring AI with Ollama, define @Tool‑annotated weather and translation utilities, register them for automatic chaining, and let a large language model answer queries like “fetch Beijing weather and reply in English” using a concise end‑to‑end example.
The article explores Feat's attempt to build a reflection‑free ORM that preserves MyBatis‑like developer experience by moving all mapping work to compile time, discusses the challenges posed by Java's AOT shift, and argues why such an experiment is both risky and worthwhile.
This article presents fifteen concrete Java performance‑optimization rules—from readable code and proper data structures to efficient string handling, database access, caching, multithreading, reflection, JVM tuning, and memory management—each illustrated with before/after code examples and practical advice.
The article examines the challenges of multiple corporate systems requiring separate logins, explains traditional session mechanisms and their limitations in clustered environments, compares session replication versus centralized storage, and presents a complete Java Spring implementation of CAS‑based single sign‑on with code samples and a discussion of differences from OAuth2.
This article demonstrates how Spring Cloud Stream provides a unified programming model that decouples business logic from the underlying message broker, allowing a single codebase to work with RocketMQ, Kafka, or RabbitMQ by only changing configuration, and walks through project structure, implementation, conditional routing, MQ switching, testing, and common pitfalls.
This article provides a comprehensive source‑code analysis of OpenFeign and Spring Cloud LoadBalancer, explaining how declarative client calls are turned into HTTP requests, why misconfigurations cause production incidents, and offering practical guidance on registration, request‑template building, instance selection, connection‑pool tuning, retries, gray releases, observability and when to evolve beyond Feign.
The article introduces JUnit's @AutoClose annotation (added in version 5.11), compares the traditional @BeforeEach/@AfterEach cleanup pattern with the annotation's automatic resource closing, and demonstrates its use across file I/O, database connections, HTTP clients, streams, and custom AutoCloseable classes, including warning behavior for null fields.
The article explains why unifying API return formats in Spring Boot prevents front‑end confusion, introduces a simple Result wrapper with code/message/data, shows manual and automatic (ResponseBodyAdvice) usage, and offers practical tips for clean, predictable backend contracts.
This article analyzes MybatisPlus Pro, explaining how it eliminates repetitive CRUD code in MyBatis‑Plus projects by providing a BaseController and utility classes that auto‑generate service and controller layers, while also detailing its internal mechanisms, advantages, drawbacks, suitable scenarios, and common pitfalls.
This article explains why local locks like synchronized and ReentrantLock fail in microservice clusters, introduces the fundamentals and essential properties of distributed locks, walks through five iterative Redis lock implementations that address dead‑lock, atomicity, and timeout issues, and finally shows how to adopt the production‑grade Redisson library with best‑practice guidelines for key naming, lock scope, and lock type selection.
The article details a complete engineering solution that lets a DingTalk group chat invoke an AI assistant—switchable between Qoder CLI and Claude Code—to query logs, run experiments, analyse performance and even deploy code, while handling intranet constraints, latency, security isolation, and Docker deployment.
This tutorial explains why microservices need a message queue, outlines RocketMQ’s core concepts, shows how to set up RocketMQ with Docker Compose, integrates it into Spring Boot projects with detailed producer and consumer code, provides testing steps, and lists common pitfalls and solutions.
Hexagonal (Ports‑and‑Adapters) architecture, introduced by Alistair Cockburn in 2005, separates core business logic from external concerns through defined ports and interchangeable adapters, enhancing testability, maintainability, and technology‑agnostic flexibility, and is especially suited for complex domains requiring multiple interfaces such as REST and message queues.
This article presents a 17‑question interview self‑test on Spring AOP, providing detailed answers that cover JDK dynamic proxy vs CGLIB, the internal flow of Proxy.newProxyInstance, InvocationHandler dispatch, MethodProxy differences, the interceptor chain, @Around requirements, AopContext ThreadLocal, self‑invocation pitfalls, final/static/private method limitations, @Order priority, Spring AOP vs AspectJ capabilities, performance of @Around vs @Before, multi‑factor aspect ordering, notification order changes between Spring 5 and 6, default proxy strategy differences in Spring Boot 2.x and 3.x, and migration considerations.
After using Codex to parallelly modify three Spring Boot tasks via isolated worktrees, the author discovers that the real bottleneck is not generating code but conducting thorough reviews to understand, validate, and safely merge AI‑produced changes.
The article explains how ZGC achieves sub‑millisecond pause times by embedding GC state in pointer bits (colored pointers) and using JIT‑injected load barriers that fix references on first access, comparing this approach with G1 and Shenandoah and detailing ZGC 2.0 enhancements and known pitfalls.
This guide walks you through installing ZLMediaKit and FFmpeg in Docker, configuring Spring Boot with the required dependencies and properties, implementing a streaming service that launches FFmpeg commands, and using a simple HTML page with flv.js to play the live or on‑demand video stream.
The article explains why Java's ThreadPoolExecutor places tasks into its work queue before creating non‑core threads, describes the underlying JDK execution steps, shows how Tomcat customizes the queue to prioritize thread creation, and warns about misconfiguring unbounded queues that can cripple performance.
Most Java developers treat enums as simple constant lists, but modern frameworks like Tomcat, Spring Boot, and RocketMQ exploit enums for state machines, strategy patterns, lambda‑driven behavior, lightweight DSLs, and more, dramatically reducing boilerplate and improving type safety.
JDK 27’s third preview (JEP 531) removes the isInitialized() and orElse() methods from the LazyConstant API, adds a Set.ofLazy() factory method, and refines the lazy‑constant design to improve composability, startup performance, thread safety, and JVM optimizations.
This article presents twenty practical rules for handling exceptions in Java, covering why catching RuntimeException is discouraged, how to avoid using exceptions for control flow, proper use of finally blocks, logging best practices, custom exception design, and early input validation to keep applications stable and maintainable.
The article explains that a single ThreadLocal object can be shared across dozens of threads because the actual data lives in each thread's own ThreadLocalMap, outlines how set/get work, highlights thread‑pool pitfalls such as stale data and memory leaks, and provides best‑practice guidelines for static declaration, proper removal, and using TransmittableThreadLocal for cross‑thread propagation.
The article examines whether Java 21’s cheap virtual threads can replace traditional thread pools, explaining the original purpose of pools, their role as natural throttlers, scenarios where virtual threads excel or fail, and practical guidelines to avoid pitfalls like pinning.
This article provides a comprehensive interview self‑test on Spring Cache, covering annotation differences, AOP internals, SpEL expressions, key generation, Redis serialization, multi‑level caching, consistency strategies, and Caffeine eviction policies, complete with code examples, diagrams, and practical recommendations.
This article demonstrates how to use Spring Boot 3.5.0 with WebSocket + STOMP to build real‑time messaging, covering environment setup, WebSocket configuration, a user‑binding interceptor, and concrete code for private‑user messages, point‑to‑point chats, and global broadcasts, complete with sample results.
The article demystifies why Java's synchronized keyword can be slower by tracing the full path from CPU cache‑coherence (MESI) through bus and cache locks, volatile, biased and lightweight locks, up to the heavyweight monitor implementation, revealing each layer’s impact on visibility, ordering and atomicity.
The article analyzes the hidden dangers of writing raw HTTP calls for large language models in Java projects—hard‑coded keys, fragile request bodies, missing retries, no observability—and demonstrates how Spring AI’s unified abstractions, built‑in resilience, streaming, function calling, and seamless Spring integration eliminate these issues while enabling effortless model switching and production‑grade AI services.
This article demonstrates five advanced techniques for creating Spring Boot prototype beans with runtime parameters—including @Bean with @Scope, ApplicationContext.getBean, @Lookup, Function beans, and ObjectProvider—providing code examples, usage notes, and output showing distinct bean instances.
This guide walks through comprehensive unit tests for Spring Boot 3.x / Spring Framework 6.x event‑driven features—covering @EventListener, ApplicationListener, @Order, @Async, TransactionalEventListener, exception propagation, multiple event publishing, POJO events, and a comparison of three asynchronous handling approaches—using JDK 17+, JUnit 5, and Spring Boot Test.
This article walks through using the Java‑based Docx4j library with Spring Boot 3.5.0 to create, style, insert images, generate tables, and read Word (docx) files, providing complete Maven dependencies, step‑by‑step code examples, and the resulting document screenshots.
The article explains why batch processing tasks often slip out of control, defines a four‑layer observability model covering status, progress, quality and performance, proposes a unified task state machine and event flow, and provides concrete metric, logging, tracing and alerting designs—including Go and Java SDK examples—for reliable production‑level batch job monitoring.
This article explains Java's functional interfaces—Predicate, Function, Consumer, Supplier, and Comparator—showing their method signatures, how to compose them, custom interface creation, common pitfalls, and concise code examples for everyday use.
The article explains that Java's Integer caching makes 1000 == 1000 false while 100 == 100 true, detailing how the IntegerCache works, why == compares references, and how reflection can expose the private cache array.
The article explains why many developers stuck with MySQL should consider PostgreSQL, highlighting its superior SQL standards support, MVCC concurrency, rich indexing, JSONB performance, full‑text search, extensive extensions, and practical installation and Java integration steps, while also comparing pros, cons, and ideal use cases.
Evrete is a lightweight, high‑performance Java rule engine that implements the RETE algorithm, complies with JSR‑94, and offers flexible rule authoring via Java code, annotations, or CSV‑driven models, with full code examples and benchmark results demonstrated for Java 21.
DigDeep is a Java‑based tool that efficiently extracts nearly one hundred types of high‑, medium‑, and low‑risk sensitive data from source files across cloud, mini‑program, app, and web environments, offering recursive scanning, risk‑level filtering, deduplication, and multi‑format export to aid security audits.
This article walks through building a Spring Security resource server with OAuth2, enabling method‑level, object‑level and URL‑level permission checks using annotations like @PreAuthorize, @PostAuthorize, @PostFilter, and demonstrates configuration, utility helpers, controller examples, testing steps, best practices, and common pitfalls.
SQLite, the server‑less, single‑file database engine, is the most widely deployed database on the planet, powering Android, iOS, browsers and countless desktop apps; this article walks through its core features, Linux installation, command‑line CRUD, language bindings for Python, C, Java and Go, plus practical backup and performance tricks.
In a high‑concurrency transaction system, the author diagnosed a 30‑second API latency caused by costly SQL scans and Java Map creation on over two million rows, then applied SQL aggregation, moved counting logic into PostgreSQL, and introduced a Caffeine cache, ultimately reducing the response time to under 0.8 seconds while highlighting relational‑database limits for massive data.
