Tag

ClassLoader

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Java Captain
Java Captain
Apr 21, 2025 · Backend Development

Understanding Java Annotations and Reflection: Built‑in Annotations, Meta‑annotations, Custom Annotations, Class Loading and Runtime Reflection

This article explains Java annotations—including built‑in, meta‑ and custom annotations—covers how they are used in Spring, describes the Java reflection mechanism, class loading process, ways to obtain Class objects, and demonstrates retrieving generic and annotation information at runtime with code examples.

AnnotationsClassLoaderMeta‑annotation
0 likes · 15 min read
Understanding Java Annotations and Reflection: Built‑in Annotations, Meta‑annotations, Custom Annotations, Class Loading and Runtime Reflection
Cognitive Technology Team
Cognitive Technology Team
Apr 18, 2025 · Fundamentals

Understanding Java Context ClassLoader and Its Role in Breaking the Parent Delegation Model

This article explains why Java introduced the Context ClassLoader to bypass the parent‑delegation model, how it enables SPI mechanisms such as JDBC drivers, and the specific class‑loading pitfalls encountered when running Spring Boot applications as executable JARs.

ClassLoaderContextClassLoaderSPI
0 likes · 7 min read
Understanding Java Context ClassLoader and Its Role in Breaking the Parent Delegation Model
FunTester
FunTester
Apr 6, 2025 · Backend Development

Understanding Java ClassLoader: Common Issues, Root Causes, and Solutions

This article explains Java's dynamic ClassLoader mechanism, outlines the hierarchy of built‑in loaders, details frequent problems such as ClassNotFoundException, NoClassDefFoundError, ClassCastException and version conflicts, and provides practical troubleshooting steps and best‑practice recommendations for reliable class loading.

ClassLoaderCustomClassLoaderDependencyManagement
0 likes · 10 min read
Understanding Java ClassLoader: Common Issues, Root Causes, and Solutions
Cognitive Technology Team
Cognitive Technology Team
Apr 5, 2025 · Fundamentals

Understanding Java ClassLoader.loadClass() API and Its Performance Impact

This article explains how the java.lang.ClassLoader#loadClass() API works, why frequent concurrent calls can cause thread blocking due to internal synchronization, demonstrates the issue with a sample multithreaded program, analyzes thread‑dump data, and provides practical solutions to mitigate the performance problem.

ClassLoaderJVMPerformance
0 likes · 12 min read
Understanding Java ClassLoader.loadClass() API and Its Performance Impact
Java Tech Enthusiast
Java Tech Enthusiast
Mar 6, 2025 · Backend Development

Java Dynamic Compilation and Runtime Hot Reload with JavaCompiler and Custom ClassLoader

By using the JavaCompiler API to compile source files at runtime together with a custom ClassLoader that loads the generated bytecode, developers can hot‑reload changed classes instantly without restarting the JVM, enabling rapid iteration, plugin‑style extensions, and faster development cycles.

ClassLoaderDynamic CompilationJavaCompiler
0 likes · 6 min read
Java Dynamic Compilation and Runtime Hot Reload with JavaCompiler and Custom ClassLoader
Selected Java Interview Questions
Selected Java Interview Questions
Feb 20, 2025 · Backend Development

Loading External JARs into Spring Boot: Four Practical Approaches

This article explains how to make custom classes visible to Spring Boot by loading external JAR files through four methods—extending the classpath, using Spring Boot's loader.path parameter, creating a custom ClassLoader, and modifying the boot classpath—while also showing how to configure scanning and packaging details.

Backend DevelopmentClassLoaderSpring Boot
0 likes · 8 min read
Loading External JARs into Spring Boot: Four Practical Approaches
Cognitive Technology Team
Cognitive Technology Team
Feb 19, 2025 · Fundamentals

Understanding Java ClassLoaders: Mechanism, Hierarchy, and Common Issues

This article explains Java's ClassLoader mechanism, its loading, linking, and initialization phases, the parent‑delegation hierarchy, common problems such as ClassNotFoundException and OOM, and provides practical troubleshooting steps and best practices for managing dynamic class loading.

ClassLoaderJVMTroubleshooting
0 likes · 6 min read
Understanding Java ClassLoaders: Mechanism, Hierarchy, and Common Issues
Selected Java Interview Questions
Selected Java Interview Questions
Jan 12, 2025 · Information Security

Encrypting and Dynamically Decrypting Spring Boot JAR Files for Secure Deployment

This article demonstrates a practical approach to protect sensitive Spring Boot applications by encrypting the JAR with AES, storing the key in a secure vault, and using a custom ClassLoader to decrypt and load classes at runtime, while highlighting key management, performance, and additional hardening considerations.

AESClassLoaderJAR encryption
0 likes · 8 min read
Encrypting and Dynamically Decrypting Spring Boot JAR Files for Secure Deployment
Java Architect Essentials
Java Architect Essentials
Dec 2, 2024 · Backend Development

Dynamic Loading of JAR Files in Spring Boot Applications

This article provides a comprehensive guide on dynamically loading JAR packages in Spring Boot, covering core concepts, benefits, and step‑by‑step implementations using SpringBootClassLoader and third‑party OSGi libraries, complete with practical code examples.

Backend DevelopmentClassLoaderDynamic JAR Loading
0 likes · 8 min read
Dynamic Loading of JAR Files in Spring Boot Applications
macrozheng
macrozheng
Oct 25, 2024 · Fundamentals

Why and How Java Breaks the Parent Delegation Model: Real-World Scenarios

This article explains the purpose of Java's parent‑delegation class‑loading mechanism, describes its three built‑in loaders, shows how custom loaders can override it, and explores common situations—such as JNDI, JDBC, Tomcat, and OSGi—where developers intentionally break the delegation for flexibility and modularity.

ClassLoaderCustom ClassLoaderJDBC
0 likes · 11 min read
Why and How Java Breaks the Parent Delegation Model: Real-World Scenarios
Java Tech Enthusiast
Java Tech Enthusiast
Oct 6, 2024 · Backend Development

Dynamic Class Loading and Unloading for Data Governance Tasks in Spring Boot with XXL‑Job

By implementing a plug‑in architecture that uses a custom URLClassLoader to load and unload JAR‑packaged governance tasks at runtime, the Spring Boot application can dynamically register Spring beans and XXL‑Job handlers, remove them cleanly, update configuration via YAML or Nacos, and package the solution with Maven Shade without restarting services.

ClassLoaderSpring Bootdynamic loading
0 likes · 21 min read
Dynamic Class Loading and Unloading for Data Governance Tasks in Spring Boot with XXL‑Job
DaTaobao Tech
DaTaobao Tech
Sep 23, 2024 · Backend Development

Root Cause Analysis of Missing Logs after Tomcat 7→8 Upgrade

After upgrading from Tomcat 7 to Tomcat 8, the application’s mixed log4j‑1.4 and logback‑1.2.3 dependencies caused the SLF4J binder to be loaded nondeterministically, so Tomcat 8 sometimes selected the Log4j binder without a configuration file, resulting in completely missing log output; removing the conflicting jars or enforcing a deterministic class‑loading order restored logging.

ClassLoaderLogbackTomcat
0 likes · 19 min read
Root Cause Analysis of Missing Logs after Tomcat 7→8 Upgrade
Java Architect Essentials
Java Architect Essentials
Sep 2, 2024 · Backend Development

Dynamic Loading of JAR Files in Spring Boot Applications

This article explains how to dynamically load JAR files in a Spring Boot application, covering core concepts, benefits, usage of SpringBootClassLoader, creation of JARs, and alternative third‑party OSGi‑resource‑locator approaches with full code examples.

ClassLoaderJarOSGi
0 likes · 8 min read
Dynamic Loading of JAR Files in Spring Boot Applications
Top Architecture Tech Stack
Top Architecture Tech Stack
Aug 27, 2024 · Backend Development

Understanding Java's Parent Delegation Model for Class Loaders

The article explains Java's parent delegation model for class loaders, its benefits for stability and security, how to break it by customizing loadClass or using thread‑context class loaders, and illustrates common scenarios such as JNDI, JDBC and Tomcat's own class‑loader hierarchy.

ClassLoaderJVMParent Delegation
0 likes · 10 min read
Understanding Java's Parent Delegation Model for Class Loaders
Top Architect
Top Architect
Jun 11, 2024 · Backend Development

Dynamic Class Loading, Registration, and Unloading for Data Governance Tasks in a Spring‑XXL‑Job Service

This article explains how to design a plug‑in architecture for a data‑governance service by using a custom URLClassLoader, Spring bean registration, and XXL‑Job integration to dynamically load, start, stop, upgrade, and unload individual governance tasks without restarting the whole service, and also shows how to persist the configuration in local YAML or Nacos.

ClassLoaderDynamicLoadingSpring
0 likes · 22 min read
Dynamic Class Loading, Registration, and Unloading for Data Governance Tasks in a Spring‑XXL‑Job Service
Code Ape Tech Column
Code Ape Tech Column
May 30, 2024 · Backend Development

Dynamic Loading of JAR Files in Spring Boot Applications

This article explains the concepts and step-by-step implementation of dynamically loading JAR packages in Spring Boot applications, covering built‑in classloader usage, creating JARs, and leveraging third‑party libraries to enhance flexibility and extensibility.

ClassLoaderJarSpring Boot
0 likes · 9 min read
Dynamic Loading of JAR Files in Spring Boot Applications
JD Tech
JD Tech
May 14, 2024 · Backend Development

Matrix Underlying Support Framework: Hot Deployment, Front‑Middle Isolation, and Business Identity Design

This article examines the Matrix middle‑platform framework used at JD.com, detailing its hot‑deployment mechanism, the push‑and‑pull integration chains, class‑loader isolation based on the parent‑delegation model, and the design of business‑identity recognition, while offering best‑practice recommendations and code examples.

ClassLoaderHot DeploymentPaaS
0 likes · 33 min read
Matrix Underlying Support Framework: Hot Deployment, Front‑Middle Isolation, and Business Identity Design
JD Retail Technology
JD Retail Technology
Mar 22, 2024 · Backend Development

Analysis of JD's Middle‑Platform Evolution and the Underlying Matrix Technical Framework

This article examines JD's practical implementation of middle‑platform (中台) evolution, detailing the design rationale, the Matrix support framework, hot‑deployment mechanisms, class‑loader isolation, and business‑identity principles to illustrate how the architecture improves delivery speed and modularity.

ClassLoaderHot DeploymentPaaS
0 likes · 32 min read
Analysis of JD's Middle‑Platform Evolution and the Underlying Matrix Technical Framework
37 Interactive Technology Team
37 Interactive Technology Team
Mar 4, 2024 · Mobile Development

Android Plugin Architecture Overview and Implementation Guide

This guide explains Android pluginization, showing how a host app can dynamically load separate APK modules—including native libraries, classes via a custom DexClassLoader, and mixed resources—while supporting hot updates, modular isolation, and reduced initial size, and details each loading step and manager implementation.

AndroidClassLoaderdynamic loading
0 likes · 31 min read
Android Plugin Architecture Overview and Implementation Guide