jvm

This repository is a Chinese-language study guide covering how the Java Virtual Machine (JVM) works at a low level. The JVM is the software layer that runs Java programs, and understanding its internals is useful for developers who want to write more efficient Java code or diagnose performance problems.

The guide is organized as a series of documents covering ten topics: how the JVM lays out memory, how objects are created and stored inside the HotSpot JVM (the most widely used Java runtime), how garbage collection works and which algorithms it uses, how the JVM decides when and how to reclaim memory, how to tune JVM performance, how compiled Java class files are structured, and how the JVM loads classes at startup and at runtime.

The content is described in the README as a summary of points the author considers most important to know, not a complete reference. Readers who want a deeper treatment are pointed to a well-known Chinese book on JVM internals. A website version of the guide is available, and following a WeChat public account associated with the project lets readers download a PDF version.

The repository is part of the Doocs open-source community, a Chinese developer learning community that maintains several other study guides on topics including advanced Java, algorithm problems, and framework source code analysis. The license is Creative Commons Attribution-ShareAlike 4.0 International.