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.
This guide walks you through Tomcat’s role as a lightweight Java web server, details the prerequisites and step‑by‑step installation, shows how to configure environment variables, adjust ports, and apply performance optimizations such as disabling AJP, switching to NIO, and tuning JVM settings for production use.
This article explains why developers should avoid overriding the HttpServlet service() method, illustrating how the default implementation handles HTTP cache negotiation, showing concrete servlet examples, and demonstrating the significant traffic and performance benefits of letting the container manage caching automatically.
This article explains the differences between JSP and Servlets, lists JSP built‑in objects and scopes, compares Session and Cookie mechanisms, describes session operation and alternatives when cookies are disabled, contrasts Spring MVC with Struts, and outlines common web security measures such as preventing SQL injection, XSS, and CSRF attacks.
This article breaks down Tomcat’s modular architecture, detailing the relationships and functions of Server, Service, Connector, Container, Engine, Host, Context, and Wrapper, and explains how the Pipeline‑Valve mechanism processes requests from start to finish.
This article explains the core concepts of Java Servlets, including their UML relationships, execution flow within a container, dual role as page and controller, and the complete lifecycle from loading to destruction, providing essential knowledge for backend development.
This article explains how to build a lightweight Tomcat-inspired web server called MyTomcat, covering its socket service, request dispatching, HTTP request/response encapsulation, servlet mapping, and demonstrates the complete project structure with illustrative diagrams and code snippets.
This article explains how to use HttpServletResponse in Java web applications to generate captcha images, control browser behavior through response headers such as caching and refresh, implement redirects, and adopt recommended absolute URL path conventions using the servlet context path.
This article explains Tomcat’s overall architecture, detailing the relationships among Server, Service, Connector, and Container, and describes how requests flow through ProtocolHandlers, Pipelines, and Valves to reach servlets and return responses.
This article explains the differences between synchronous, asynchronous, blocking and non‑blocking execution, illustrates their combinations with real‑world analogies, and provides practical guidance on applying servlet async, Spring MVC async, full‑chain async, HTTP client async and database async techniques to improve Java backend throughput and CPU utilization.
This tutorial walks Java backend developers through the complete process of understanding Spring MVC’s request flow, designing a custom MVC framework, and implementing core components such as DispatcherServlet, annotations, and handler mappings with full code examples and deployment instructions.
This article demonstrates how to use Apache POI in Java to export collections of JavaBean objects to Excel files, covering generic reflection‑based implementation, styling, handling of dates, booleans, images, and integration with a servlet for download.
This article explains how to create a web page that enables downloading zip archives and images by first using simple hyperlink references and then implementing a Java Servlet that streams files with proper MIME types and Content‑Disposition headers, ensuring consistent download behavior across browsers.
This article explains the Java Servlet lifecycle—including loading, initialization, request handling, multithreading considerations, and destruction—detailing how Tomcat manages servlets, the role of init(), service(), and destroy() methods, and best practices for resource management and thread safety.
This article explains how HttpServletResponse represents server responses in Java web applications, covering methods for sending data, headers, and status codes, demonstrates outputting Chinese characters via OutputStream and PrintWriter, shows numeric output handling, and provides detailed examples of file download implementations with proper encoding considerations.
This article walks through the evolution of Java web development, comparing the classic web.xml configuration with Servlet 3.0 annotations, Spring’s ServletContainerInitializer, and Spring Boot’s embedded‑container registration mechanisms, while exposing the underlying source code and initialization flow.
This article provides a comprehensive tutorial on using ServletConfig and ServletContext in Java web development, covering how to configure and retrieve servlet initialization parameters, share data between servlets, forward requests, read resource files, and set client‑side caching for servlet responses, with complete code examples.
This article provides a comprehensive tutorial on Java Servlets, covering their purpose, lifecycle, creation in Eclipse, configuration of web.xml mappings, URL pattern rules, default servlet behavior, thread‑safety concerns, synchronization techniques, and the deprecated SingleThreadModel approach.
This article explains the evolution of Java application servers, the inner workings of servlet containers, and provides a detailed walkthrough of Tomcat’s components, request handling flow, and key performance‑tuning considerations for modern backend development.
This tutorial walks through building a lightweight Spring MVC clone in Java, covering the MVC workflow, nine core components, project setup, custom annotations, a DispatcherServlet implementation, and a test controller, with full source code and deployment instructions.
This article explains the fundamentals of the HTTP protocol, compares HTTP/1.0 and HTTP/1.1, details request and response structures, and demonstrates how to control browser behavior with various response headers using Java servlet examples.
This guide demonstrates how to create a CAPTCHA verification feature in Java by generating random characters and interference lines using Graphics, serving the image via a servlet, and integrating it into an HTML registration page with JavaScript for dynamic refresh.
This article breaks down Tomcat’s modular architecture, explaining how a single Server contains multiple Services, each pairing Connectors and a Container, and details the inner workings of Connectors, Containers, and their pipeline‑Valve processing to help developers master Tomcat internals.
This article provides a comprehensive technical guide to Tomcat, covering its kernel implementation principles, server models, distributed clustering strategies, production deployment parameters, JVM tuning, request processing flow, servlet mechanisms, filter chains, Comet and WebSocket modes, as well as performance monitoring and optimization techniques.
The author recounts a recent Alibaba Java Web interview journey, reflects on gaps uncovered during the process, and compiles a comprehensive list of core Java Web concepts—including JVM internals, servlets, Spring, Hibernate, Struts, HTTP fundamentals, and design patterns—to guide future learning and preparation.
This guide walks through cloning the LanguageTool repository, building it with Maven, extracting the required JARs, creating a servlet that uses JLanguageTool to check English text, handling language‑code issues by packaging META‑INF resources, and finally testing the service with curl.
This guide outlines the core knowledge areas for Java web development, covering JVM fundamentals, servlet lifecycle, major frameworks like Spring and Hibernate, HTTP essentials, and design patterns, offering a concise roadmap for aspiring backend engineers.
This article describes how a Java‑based HTTP service was transformed from a synchronous, thread‑blocking design to a fully asynchronous architecture by evaluating coroutine, Actor model, and Rx approaches, and ultimately implementing a Graph‑Based Execution Engine integrated with Servlet 3.0 and Spring MVC to improve stability, performance, and throughput.
This article explains the concept, functions, development steps, configuration, lifecycle methods, and practical examples of Java Servlet Filters, showing how they intercept requests and responses, modify data, and integrate with web.xml, Spring, Hibernate, and Struts2 for backend web applications.
This article provides a comprehensive overview of Apache Tomcat's modular architecture, detailing the roles and interactions of Connectors, Containers, Services, Servers, and the Lifecycle interface, while illustrating key implementation classes and code snippets that govern request handling and component management.
This guide explains five common scenarios where Chinese characters appear garbled in Java web applications—JSP pages, servlets, POST form submissions, URI parameters, and properties files—and provides step‑by‑step configurations such as setting pageEncoding, response content type, request character encoding, Tomcat URIEncoding, and using native2ascii.
This article explains the purpose and structure of the HTTP protocol, using a humorous story and Java code examples to illustrate request‑response mechanics, URL syntax, headers, and servlet interfaces, helping developers grasp how browsers and servers communicate over the web.
The article explains why repeatedly redeploying a Java servlet can trigger a java.lang.OutOfMemoryError: PermGen space, describes how classloader leaks occur, illustrates the problem with memory diagrams, and offers practical tips for detecting and fixing such leaks in backend applications.
This guide explains why and how to turn off Tomcat's TLD scanning during startup, shows the necessary context.xml changes, addresses a Tomcat 6 pitfall with a custom JarScanner workaround, and notes that Tomcat 7 handles the setting correctly.
This article explains the fundamentals of web servers, application servers, and web containers, describes the Java Servlet API—including Servlet, ServletContext, ServletRequest, ServletResponse, and session handling—and provides guidance on thread safety with illustrative code examples.
This tutorial explains the basics of QR codes and provides step‑by‑step Java examples—including a Hello World program, URL encoding, image customization, and a servlet implementation—showing how to generate and serve QR codes using the ZXing and QRGen libraries.
