This tutorial walks through building a Spring Boot application, integrating Micrometer for metric collection, deploying Prometheus and Grafana via Docker, configuring dynamic service discovery, and creating custom request‑count metrics with AOP, providing a complete end‑to‑end monitoring solution.
This article explains how to build a simple two‑level caching solution in Java, covering generic cache interfaces, FIFO/LRU/LFU algorithms, implementing local Guava cache and distributed Redis cache, configuring Spring Boot, handling expiration, and providing a unified cache builder for seamless use.
This article explains how Spring Boot 2.x handles favicons, why the default icon can expose framework details, how to disable it, and provides step‑by‑step instructions and code snippets for adding a custom favicon using Thymeleaf or plain HTML while addressing common caching issues.
This article explains the concept of a DataSource, compares it with core JDBC APIs, and provides a step‑by‑step guide to configuring Spring Boot 2.x’s default HikariCP connection pool, including common properties, their meanings, and links to full example projects.
This guide walks you through configuring data sources in Spring Boot, adding JDBC dependencies, using embedded databases, connecting to MySQL, defining entities and repositories with JdbcTemplate, and writing comprehensive unit tests to perform CRUD operations, illustrating a complete backend data access workflow.
This tutorial demonstrates how to create a User table, define the corresponding entity and mapper classes, and perform basic MyBatis-Plus queries such as selectList, selectById, selectBatchIds, and selectByMap, including the required SQL scripts and Java code examples.
This tutorial walks you through using Spring Boot Actuator to monitor microservice applications, covering quick setup, essential endpoints such as health, metrics, loggers, and shutdown, customizing health indicators, dynamically changing log levels at runtime, and securing actuator endpoints with Spring Security.
Upgrading to Spring Boot 2.2.3 can cause the pigx-gateway service to fail at startup due to an incompatible reactor‑netty ConnectionProvider method, and the article explains the root cause, investigation steps, and how to fix it by adjusting reactor‑netty versions.
The Spring Framework 5.1.13 release introduces header support in ResponseStatusException, deprecates PathResource, enhances ClientCodecConfigurer, optimizes UriUtils, adds wildcard variable resolution, and fixes ContentDisposition parsing, while Spring Boot 2.2.3 upgrades to Framework 5.2.3 with security patches, new error handling, metric improvements, and numerous bug fixes.
This article explains why graceful shutdown is important for Spring Boot services and demonstrates five practical methods—including Actuator shutdown, context closing, PID file handling, SpringApplication.exit, and a custom controller—each with complete code examples and usage instructions.
This article explains how the @Import annotation in the pig4cloud framework can be used to import components, implement dynamic routing, and register beans via ImportSelector and ImportBeanDefinitionRegistrar, providing concise architecture and easy activation of OAuth resource servers.
This tutorial walks through the fundamentals of Thymeleaf, its key features, a side‑by‑side comparison with FreeMarker, and provides a complete Spring Boot example—including Maven dependencies, entity and controller code, template markup, and essential configuration settings—to help developers integrate the template engine quickly and correctly.
This article explains how to integrate the Activiti BPMN 2.0 workflow engine into a Spring Boot application, covering Maven dependencies, data source and Activiti configuration, Spring MVC setup, Java code for starting, approving, and querying leave requests, as well as a simple AngularJS front‑end for task management.
Learn how to declare custom Servlet Filters in Spring Boot, control their execution order and URL scope using both manual bean definitions and Spring's FilterRegistrationBean, with complete code examples and best‑practice tips for secure, maintainable backend development.
This article explains how to achieve interface idempotency in a Spring Boot application by generating a unique token for each request, storing it in Redis, validating the token via a custom annotation and interceptor, and provides complete code examples and testing guidance.
This tutorial explains how Spring Boot automatically configures Jackson's ObjectMapper, shows how to override it with a custom mapper that formats Date fields, and demonstrates both serialization and deserialization of JSON using the customized ObjectMapper in a Spring MVC controller.
This article explains the five ways Spring Boot can execute code during application startup—including CommandLineRunner, ApplicationRunner, ApplicationListener, @PostConstruct, and InitializingBean—detailing their usage, ordering, argument parsing, and best‑practice recommendations.
This guide explains how Spring Boot automatically configures JSON libraries like Jackson, shows how to add the necessary starter, demonstrates returning JSON objects with @RestController, and illustrates receiving JSON payloads via @RequestBody with complete MockMvc test examples.
This tutorial walks you through installing Postman, creating and sending API requests to a Spring Boot login endpoint, using variables and environments for flexible testing, and generating code snippets in various languages, providing a practical foundation for everyday backend development tasks.
This article explains how Spring Boot's profile mechanism lets developers maintain separate configuration files for development, testing, and production environments, showing both properties and YAML examples, command‑line activation, and a deep dive into the underlying source code that processes these profiles.
This article provides a comprehensive overview of the most commonly used Spring Boot annotations—including core, configuration, web, and JPA annotations—explaining their purpose, typical usage, and how they replace traditional XML configuration in modern Java applications.
This article provides a comprehensive introduction to the Spring ecosystem, covering its core concepts such as IoC and AOP, detailing each of the seven framework modules, and explaining related projects like Spring MVC, Spring Security, Spring Data, Spring Boot, and Spring Cloud for modern Java backend development.
This guide introduces Spring Security fundamentals, explaining authentication and authorization concepts, the core interfaces such as AuthenticationManager and AccessDecisionManager, how to configure them with Spring Boot, customize filter chains, apply method‑level security, and handle thread‑bound security contexts for asynchronous processing.
This guide explains the purpose and mechanics of Spring Boot's @Conditional annotation, shows its source definition, outlines usage forms, provides a complete example with custom Condition implementations for MySQL and Oracle beans, and lists the related derived conditional annotations available in Spring Boot.
This article explains how to declare Maven dependencies for Spring Boot Admin, adds Russian language support for internationalization, and resolves a bug where setting the log level for service instances fails due to an incorrect Accept header.
This guide explains how to use Spring Boot's @ConfigurationProperties for type‑safe property binding, covering basic usage, custom property files, third‑party component binding, relaxed naming rules, validation, and extending support to YAML files with code examples and tests.
This article explains how to implement asynchronous requests and asynchronous method calls in Spring Boot, covering servlet‑based async, Callable, WebAsyncTask, DeferredResult, @Async annotation, thread‑pool configuration, common pitfalls, and the differences between async request and async call.
Spring Boot lets you pass configuration via command-line arguments when launching a JAR, supporting option, non‑option, and system parameters; this guide explains how to use each form, retrieve values through ApplicationArguments or @Value, and walks through the underlying source code that parses and injects these arguments.
This article demonstrates how to integrate the Activiti 6.0 workflow engine into a Spring Boot application, covering Maven dependencies, YAML configuration, Spring MVC setup, Java service methods for starting, auditing, and querying leave processes, as well as an AngularJS front‑end for task handling.
This article walks through designing and implementing a high‑traffic like/unlike feature for a social platform using Spring Cloud, Redis caching, MySQL persistence, and a Quartz‑based scheduled job to sync data every two hours.
This article demonstrates how to implement database read‑write splitting in a Spring Boot application by configuring multiple MySQL data sources, creating a custom AbstractRoutingDataSource, using ThreadLocal routing keys, and applying AOP to switch between master and slave databases for CRUD operations.
This article explains Java annotation fundamentals, explores built‑in meta‑annotations, demonstrates how to create compile‑time and runtime custom annotations, and shows how to integrate them with Spring Boot AOP for automatic logging and request handling.
Tangram is a home‑grown configuration center that replaces Spring Config Server by leveraging etcd’s high‑availability KV store, watch‑based dynamic updates, and multi‑language support to provide reliable, secure, and real‑time configuration management for microservice architectures.
This article explains how Java memory leaks can occur despite automatic garbage collection, describes JVM GC‑Root analysis, outlines practical monitoring with Spring Boot Actuator, Prometheus, and Grafana, and provides step‑by‑step debugging commands and code adjustments to locate and fix the leak.
This article explains how Java memory leaks can occur despite automatic garbage collection, describes JVM reachability analysis, shows how to monitor and detect leaks using Spring Boot Actuator, Prometheus, and Grafana, and provides step‑by‑step instructions for heap dump analysis and code fixes.
This tutorial walks through creating a SaaS application with Spring Boot that supports multiple tenants by using independent or shared databases with separate schemas, covering tenant identification, dynamic DataSource routing, Hibernate multi‑tenancy configuration, and a complete code example including Maven setup, entity definitions, interceptors, and a login test.
This article explains the distinctions between Spring, Spring MVC, and Spring Boot, illustrates how Spring Boot achieves automatic configuration through annotations like @SpringBootApplication, @EnableAutoConfiguration, and @ComponentScan, and provides detailed code examples of the underlying mechanisms and related configuration classes.
This article explains how to use Bean Validation in Spring Boot to replace repetitive IF‑ELSE checks with annotation‑driven parameter checks, covers built‑in and Hibernate‑specific constraints, demonstrates custom validators, group validation, and shows how to centralize error responses with a global exception handler.
Spring Boot 2.1 will stop receiving updates after November 1 2020, with only critical bug and security fixes provided beforehand, so users should smoothly upgrade to the actively maintained 2.2 release which introduced in October 2019 and remains fully supported.
This guide walks through diagnosing GPG signing failures caused by expired keys during a swagger‑spring‑boot‑starter release, shows how to inspect the current keyring, edit the key, extend its validity, and finally re‑run Maven deploy to publish artifacts.
This article explains the purpose, source code, and practical usage of Spring Boot’s @ConditionalOnProperty annotation, illustrating how it enables or disables auto‑configuration through property prefixes, names, havingValue, and matchIfMissing attributes with concrete code examples.
Spring Boot Admin 2.2.0 introduces core dependency upgrades, multi‑language support for five languages, enhanced detail pages, login personalization, instance filtering via metadata, and a series of bug fixes, providing a richer monitoring experience for Spring‑based applications.
A Spring Boot 1.5.7 application suddenly stops starting because the main thread is blocked, the stack trace shows a NoSuchMethodError for ObjectUtils.unwrapOptional, which is traced back to a mismatched spring‑context 5.x jar overriding the original 4.x version, and the article explains how to identify and resolve the dependency conflict.
This article demonstrates how to create a custom @AccessLimit annotation, implement a Spring MVC interceptor that uses Redis to count requests, register the interceptor in a Spring Boot application, and apply the annotation to controller methods to achieve rate‑limiting functionality.
This article explains a Flyway permission error that occurs when deploying a Spring Boot application, analyzes its cause, and provides two practical solutions: granting the necessary MySQL privileges or downgrading to a compatible Flyway version.
Spring Cloud Hoxton RELEASE, built on Spring Boot 2.2.1, introduces major reactive enhancements, a new load‑balancer implementation, updated documentation with PDF support, and numerous changes across Gateway, Netflix, Config, Sleuth, and Discovery clients, providing a comprehensive upgrade path for developers.
The author, a former PHP engineer at Mafengwo, chronicles a two‑day crash‑course in Java and Spring Boot, detailing the adoption of Lombok, Druid, Maven, and various annotations while navigating pitfalls such as bean scopes, database connections, and data format mismatches before successfully launching the new service.
This article explains the fundamentals of unit testing in Java, covering what unit tests are, why they matter, when to write them, and detailed step‑by‑step examples using Mockito, PowerMock, JUnit, and Spring Boot to mock dependencies, verify behavior, and assert results across DAO, service, and controller layers.
This guide explains how to integrate springdoc-openapi with Spring Boot to automatically generate OpenAPI 3 documentation, customize paths, combine with Swagger UI, use Maven plugins, support WebFlux, apply JSR‑303 bean validation, and document error responses via @ControllerAdvice, providing complete code snippets and configuration examples.
This tutorial explains how Spring Boot handles static resources, covering the default classpath directories, a simple manual file‑stream approach, and ways to customize resource locations using Java configuration or application.yml, with code examples and practical URLs.
This article walks through customizing Spring Security in a Spring Boot application by creating a custom security configuration class, overriding authentication manager, web security, and HttpSecurity methods, and explains the default and common HttpSecurity settings with code examples.
Spring Cloud Greenwich SR4 has been released, upgrading the underlying Spring Boot to 2.1.10, adding LoadBalancer support to Gateway, removing @EnableDiscoveryClient, updating OpenFeign to 10.4.0 with Google HTTP Client and JDK Proxy support, fixing bugs, and providing pom dependency changes.
This article explores how Spring Security is automatically configured in Spring Boot, detailing key auto‑configuration classes such as SecurityAutoConfiguration, SpringBootWebSecurityConfiguration, WebSecurityEnablerConfiguration, and the @EnableWebSecurity annotation, while providing code snippets and explanations of their roles in the security filter chain.
This tutorial walks you through creating a custom Spring Boot starter, covering project structure, naming conventions, auto‑configuration module, property management, Maven setup, sample usage, and best practices, enabling you to package reusable cross‑cutting functionality for any Spring application.
This article explains why to use Spring Boot, how to set up the development environment, and provides step‑by‑step instructions for integrating MyBatis, Swagger2, multi‑environment profiles, and advanced Logback logging, including configuration files, Maven dependencies, code snippets, and testing procedures.
Mobile developers should learn backend development to improve communication, resolve API inconsistencies, build data aggregation layers, and create their own infrastructure, and can start by mastering Spring Boot, SSM architecture, Dubbo, MySQL/MyBatis, and optional tools like Redis and security frameworks.
This article explains how using @Configuration(proxyBeanMethods=false) in Spring Boot 2.2 reduces bean proxy generation, cuts startup time by several seconds, and provides step‑by‑step code examples, performance logs, and best‑practice recommendations for modern Java microservices.
The BIM construction‑drawing team built an automated monitoring and validation tool using Spring Boot, REST‑Assured and JIRA APIs, turning a tedious manual bug‑fix workflow into a streamlined process that reduced online drawing‑failure rates from 0.01% to virtually zero.
This tutorial explains the fundamentals of SMTP, IMAP, and POP3 protocols, demonstrates how to use Spring's JavaMailSender and JavaMailSenderImpl for simple and complex email sending, provides step‑by‑step project setup, configuration, code examples, a Thymeleaf UI, testing instructions, and a detailed list of common mail server error codes.
This guide walks through integrating Spring Security with Spring Boot, explains the UserDetailsServiceAutoConfiguration, demonstrates how to customize UserDetailsManager using in‑memory storage, and shows how to extend it for database‑backed user management, providing complete code examples and practical insights.
Spring Boot 2.2.1, released on November 7, 2019, introduces 110 fixes and disables automatic @ConfigurationProperties scanning by default, requiring developers to add @ConfigurationPropertiesScan manually, with full details available in the official GitHub issue.
This article explains how @ConfigurationProperties and @ConfigurationPropertiesScan work in Spring Boot, the differences from @Value, and why upgrading from 2.2.0 to 2.2.1 may cause configuration beans to stop loading.
This article provides a comprehensive tutorial on building a full‑stack application by setting up front‑end tools like Node.js and Vue.js, creating Vue projects with CLI, using Vue directives, routing and Axios for API calls, and integrating a Spring Boot backend with RESTful services, Dubbo RPC, and Spring Cloud components for microservice architecture.
This article demonstrates how to combine Spring Boot with MyBatis, Druid connection pool, and PageHelper pagination plugin to configure multiple data sources, set up monitoring, and perform efficient paged queries, providing complete Maven dependencies, property settings, and Java configuration examples.
This guide walks through creating a Spring Boot starter from scratch, covering Maven project setup, defining service and utility classes, configuring properties, implementing auto‑configuration with conditional annotations, registering the starter via spring.factories, and consuming it in another Spring Boot application.
This tutorial explains how to use Spring Boot's Configuration Processor to generate JSON metadata for configuration properties, covering dependency setup, Java bean definitions, property files, tests, and how the resulting metadata improves IDE auto‑completion and documentation.
The article introduces the Pig microservice scaffold built on Spring Cloud Hoxton and Spring Boot 2.2, outlines its key features such as OAuth2 RBAC, element‑ui integration, Docker/Kubernetes support, details version changes, provides upgrade issue solutions, and shares future plans for Hoxton and Spring Boot releases.
This article explains how Java backend developers can replace memory‑heavy Apache POI with EasyExcel for fast, low‑memory Excel imports, covering basic reading, custom converters for gender and dates, and multiple Spring Boot integration patterns including controllers, listeners, constructor injection and lambda‑based approaches.
This article introduces Spring Cloud Security and demonstrates how to integrate OAuth2 for single sign‑on, token relay, and token exchange in a Spring Boot application, covering OAuth2 concepts, authorization flows, module setup, configuration, and practical usage of authorization‑code and password grant types with code examples.
This article examines how Spring Boot 2.2.0.RELEASE loads configuration files, where it searches for them, how it supports YAML and properties formats, how to add JSON support, the precedence of property sources, and the placeholder resolution process by tracing the relevant source code.
This tutorial shows how to add iText and XHTMLRenderer dependencies, create a PDF utility class that supports Chinese fonts, configure Maven resources to avoid placeholder conflicts, and resolve Docker build issues, all illustrated with a working demo image.
Spring Cloud Gateway provides a powerful, reactive API gateway for Spring Boot applications, offering dynamic routing, predicates, and a variety of filters such as rate limiting, retries, and circuit breaking, with detailed examples of configuration via YAML and Java beans, integration with Eureka, and practical code snippets.
This tutorial walks through writing and running unit and integration tests for a Spring Boot application, covering JUnit and Hamcrest assertions, Maven setup, model definitions, service and controller implementations, MockMvc usage, and both mocked and real‑world test scenarios, complete with sample code and output.
This article chronicles the evolution of Spring Cloud Alibaba from its Spring Boot roots, detailing its incubation, major releases, core features, community adoption, and its role in advancing cloud‑native microservice architectures in the Chinese tech ecosystem.
Spring Boot 2.2 follows the release of Spring Framework 5.2, bringing updated component versions, major performance gains, Java 13 support, immutable configuration properties, RSocket starter, health‑check grouping, and numerous other enhancements for Java backend developers.
This tutorial demonstrates how to enable shared HTTP sessions across multiple Spring Boot instances by integrating Apache Shiro with Redis via the CrazyCake plugin, configuring Maven dependencies, Redis and Shiro settings, building service and controller layers, and deploying the applications behind an Nginx load balancer for seamless session persistence.
This guide explains how to use Swagger2Markup to convert Swagger-generated API specifications into static documentation formats such as AsciiDoc, Markdown, Confluence markup, and HTML, covering both Java code and Maven plugin approaches, deployment options, and example configurations for Spring Boot projects.
This article explains how to integrate Apache Kafka with Spring Boot, covering error handling with SeekToCurrentErrorHandler, deserialization error handling, type‑inferred message conversion, multi‑listener routing, and transactional message processing, providing code examples and configuration details for each feature.
This article compiles essential Spring Boot interview questions covering its distinction from Spring, Maven setup, starter modules, disabling and registering auto‑configurations, conditional beans, packaging as JAR/WAR, startup logic, external configuration sources, testing nuances, and the powerful Actuator monitoring features.
This article explains how to control the organization, grouping, and ordering of API documentation in Swagger for Spring Boot projects, covering controller-based tags, custom tag names, merging groups, fine‑grained operation tags, and sorting of tags, operations, and parameters.
This tutorial explains why server‑side request parameter validation is essential, introduces the JSR‑303 Bean Validation standard and its Hibernate Validator implementation, and provides step‑by‑step code examples, Swagger integration tips, and dependency guidance for building robust Spring Boot REST APIs.
This tutorial explains how to integrate Swagger2 into a Spring Boot RESTful API project, covering dependency setup, configuration, annotation usage, and UI testing, enabling automatic, maintainable API documentation for multiple client platforms.
The article documents a series of Spring Boot 2.1 startup benchmarks on OpenJDK 11, exploring fifteen different tweaks—from using WebFlux instead of WebMVC to enabling AppCDS and disabling unnecessary libraries—showing how each change impacts launch time and culminating in a sub‑second startup.
This tutorial walks you through Spring Boot 2.x fundamentals, explaining core MVC annotations, defining a User entity with Lombok, creating a full RESTful CRUD controller, and writing comprehensive MockMvc unit tests to verify each endpoint.
Spring, Spring MVC, Spring Boot, and Spring Cloud are Java frameworks that respectively provide core IoC/AOP functionality, web MVC capabilities, convention‑over‑configuration rapid development, and comprehensive microservice governance, together forming a layered ecosystem for building clean, manageable, and scalable backend applications.
This article explains how Spring Boot launches an embedded Tomcat server by tracing the main method, creating and refreshing the application context, and initializing Tomcat's core components such as connectors and containers, while detailing the hierarchy of Engine, Host, Context, and Wrapper.
This article explains how to integrate the rsa-encrypt-body-spring-boot starter into a Spring Boot project to uniformly encrypt request parameters and response bodies using RSA and AES, providing step‑by‑step configuration, code examples, and practical encryption tips.
This article explains how to configure Logback in a Spring Boot application to separate logs by level into different files, implement asynchronous logging to reduce disk I/O, and demonstrates a performance test showing a ten‑fold throughput increase, while also detailing the underlying async mechanism.
This tutorial demonstrates how to create a Spring Boot project, define a GraphQL schema, implement data fetchers, expose REST endpoints, and query book data using GraphQL, highlighting the advantages of GraphQL over traditional REST APIs.
This article presents a curated collection of notable open‑source Java backend projects—including Spring Boot demos, third‑party login libraries, microservice frameworks, rapid development kits, and e‑commerce tutorials—each with brief descriptions and GitHub links for developers to explore and learn from.
Learn how to create a reactive REST API using Spring Boot and RxJava, covering prerequisite knowledge, required dependencies, CRUD endpoint definitions, service layer implementation with RxJava Single, and web controller integration, plus essential Maven setup and tips to avoid common HttpMediaNotAcceptableException errors.
This article explains the challenges of session sharing in distributed Spring Boot applications, demonstrates how to centralize session data using Redis, and shows how Spring Session simplifies the process by automatically synchronizing session information across multiple Tomcat instances.
This tutorial demonstrates how to integrate the lightweight Apache Shiro security framework into a Spring Boot 2.1.5 project, covering environment setup, Maven dependencies, Redis session storage, custom utilities, Shiro configuration, permission annotations, test controllers, and Postman verification.
This tutorial walks through installing JDK and Maven on a CentOS server, cloning a Spring Boot Hello World project, building it with Maven, installing Docker, creating a Dockerfile, building and running the Docker image, and finally managing the container lifecycle.
This tutorial walks through setting up Spring Boot Admin as a monitoring server and client, integrating it with Eureka for service discovery, adding Spring Security for authentication, and configuring email and custom notifications, complete with Maven and YAML configurations and Java code examples.
This article explains why adding spring-boot-devtools can trigger a ClassCastException due to its dual classloader mechanism, demonstrates how to reproduce the issue in a Maven multi‑module project, and provides two practical solutions: customizing the RestartClassLoader or removing the devtools dependency.
This article provides a detailed overview of the most commonly used Spring MVC request‑mapping annotations, Spring Bean stereotypes, dependency‑injection and scope annotations, container configuration annotations such as @Autowired and @Primary, and essential Spring Boot annotations, illustrating each with clear code examples and diagrams.
This tutorial walks through integrating Dubbo into a Spring Cloud Alibaba project using Nacos as the service registry, covering interface definition, provider and consumer setup, Maven dependencies, configuration details, testing, and the benefits of combining Dubbo's RPC performance with Spring Cloud's ecosystem.
This article explores the inner workings of Spring Boot Profiles by tracing source code, examining how configuration files are loaded, how the environment and active profiles are created, and how profile-specific properties are applied during application startup.
This guide explains how to enable Spring Boot's default metrics via Actuator, view them through the /actuator/metrics endpoint, and enrich them with Micrometer MeterBinders for JVM, cache, Hibernate, and Tomcat, including code samples and logging output.
