Introducing full-stack Internet architecture technologies centered on Java
This guide explains the concepts of ZooKeeper cluster roles and provides step‑by‑step instructions, including configuration file edits and command‑line operations, to set up a pseudo‑cluster on a single machine for testing and learning purposes.
This article explains Java annotations, their purposes such as providing compiler metadata, generating code, runtime processing, and documentation, introduces built‑in and meta‑annotations, and demonstrates how to create and use custom annotations both via reflection and with Spring AOP for logging, including full code examples.
This article explains what ZooKeeper is, describes its data model and four znode types, introduces the watch mechanism, and provides step‑by‑step commands for installing ZooKeeper, creating nodes, and verifying the service on a Java‑enabled machine.
This article explains the Observer behavioral design pattern, describes its participants, illustrates a real‑world e‑commerce scenario, and provides complete Java code for the observer interface, subject interface, concrete subject, concrete observers, and a test client, concluding with the pattern’s benefits.
This tutorial walks you through creating a Spring Cloud Alibaba project from scratch using IntelliJ IDEA and Maven, covering parent project setup, module creation, pom.xml configuration, a simple Spring Boot application, a Hello World controller, and how to run and verify the service.
This article explains the fundamentals of the Spring framework and its ecosystem—including Spring Boot, Spring Cloud, and Spring Cloud Alibaba—detailing their core concepts, advantages, and how they interrelate to simplify Java enterprise and micro‑service development.
This article explains the Chain of Responsibility design pattern, its roles, and how to implement it in Java using a leave‑approval scenario to achieve decoupled, flexible, and easily extensible request handling across multiple handlers.
The Builder pattern separates object construction from its representation, enabling the same construction process to produce varied complex objects, and is illustrated through a Java house-building example that defines abstract and concrete builders, a product class, a director, and client code.
This article demonstrates how to use MySQL to create employee and performance tables, populate them with sample data, and write SQL statements that first select employees whose salaries exceed their department's average and then filter out those with non‑A performance ratings, providing a complete layoff‑target list.
This article explains how to identify and remove duplicate rows in a MySQL table—keeping a single record per duplicate group—by using a self‑join DELETE statement or a nested subquery approach, complete with sample table creation and data insertion scripts.
