Former Ant Group P8 engineer, pure technologist, sharing full‑stack Java, job interview and career advice through a column. Site: java-family.cn
When a production error generates a massive log file, this guide teaches backend engineers how to efficiently inspect and troubleshoot using Linux commands like tail, less, grep, sed, and awk, with concrete real‑world scenarios and exact command examples.
A Spring Boot channel service showed an unexpected 100 ms latency; by systematically checking network, using curl, and employing Arthas to trace Spring MVC and Tomcat internals, the author discovered a Tomcat‑embed bug that repeatedly loads Swagger‑UI JAR resources, which is resolved by upgrading Tomcat.
This article introduces a powerful, extensible Spring validation component built on SpEL that handles simple annotations, enum checks, multi‑field logic, and Spring Bean integration, providing step‑by‑step setup, usage examples, custom constraints, and performance considerations for Java backend developers.
This article explains how to import 1 billion 1 KB log records stored in HDFS/S3 into MySQL by analyzing single‑table limits, proposing sharding into multiple tables, choosing the right storage engine, using batch inserts, controlling concurrency, and ensuring ordered, reliable processing with Redis and Redisson.
When a Spring Boot application using @Scheduled is deployed on multiple servers, each instance triggers the same job, leading to duplicate processing; this article explains why the problem occurs, reviews simple single‑node and Redis lock approaches, and provides a step‑by‑step guide to integrate the ShedLock framework for reliable, annotation‑driven distributed locking.
This article explains how to replace static permission annotations in Spring Boot with flexible SpEL expressions, showing step‑by‑step how to create a @PreAuth annotation, an AOP aspect, an expression parser, and a utility class that evaluates role‑ and time‑based access rules at runtime.
JSONPath offers a concise, XPath‑like syntax for extracting data from complex JSON structures, and this guide shows how to integrate it into Spring Boot, compare FastJSON, Jackson, and Gson implementations, and provides practical code examples, advanced configurations, and selection advice for Java projects.
This article introduces a powerful visual service‑management script for SpringBoot applications that replaces manual start‑stop commands with an interactive, color‑coded console, offering configuration‑driven control, intelligent start/stop flows, real‑time monitoring, log handling, batch operations, automated deployment and safe rollback to dramatically improve operational efficiency and reliability.
This article explains why the decades‑old Syslog protocol remains relevant in modern microservice and cloud‑native environments, detailing its structure, advantages, typical use cases, step‑by‑step server setup with rsyslog, command‑line analysis techniques, integration with Java applications, and a comparison with ELK/Loki solutions.
This guide walks through switching a SpringBoot + MyBatisPlus project from MySQL to PostgreSQL, covering driver setup, JDBC changes, numerous SQL syntax differences, type conversion issues, transaction handling, and provides helper scripts for bulk schema adjustments.
