Rust for Java Programmers
Rust 面向 Java 程序员

AI-driven guide: Written with GPT-5.4 assistance for experienced Java developers who want to learn Rust with clear conceptual mapping and practical migration advice.
AI 驱动说明：本书由 GPT-5.4 协助撰写，面向已经有 Java 经验、希望系统学习 Rust 的开发者。

This book is a bridge text. It assumes comfort with Java, Maven or Gradle, the JVM, exceptions, interfaces, streams, and the usual enterprise toolkit. The goal is not to re-teach programming. The goal is to show which instincts transfer cleanly, which ones must change, and how to reach idiomatic Rust without dragging Java habits everywhere.
这本书定位成桥接教材。默认已经熟悉 Java、Maven 或 Gradle、JVM、异常、接口、Stream，以及常见企业开发工具。重点不是重复教授编程基础，而是说明哪些经验可以平移，哪些习惯必须调整，以及怎样走到更符合 Rust 社区习惯的写法。

Who This Book Is For
适合哪些读者

Developers who already write Java for backend services, tooling, data pipelines, or libraries
已经用 Java 写后端服务、工具、数据处理程序或基础库的开发者。
Teams evaluating Rust for performance-sensitive or safety-sensitive components
正在评估 Rust，用于性能敏感或安全敏感模块的团队。
Readers who want a chapter order that moves from syntax and ownership into async, FFI, and migration strategy
希望按“语法与所有权 → async → FFI → 迁移策略”顺序系统推进的读者。

What You Will Learn
这本书会覆盖什么

How Rust differs from Java in memory management, error handling, type modeling, and concurrency
Rust 在内存管理、错误处理、类型建模和并发方面与 Java 的核心差异。
How to map Java concepts such as interfaces, records, streams, Optional, and CompletableFuture into Rust equivalents
如何把接口、record、Stream、Optional、CompletableFuture 这些 Java 经验映射到 Rust 世界。
How to structure real Rust projects with Cargo, crates, modules, testing, and common ecosystem tools
如何使用 Cargo、crate、模块、测试和常见生态工具来组织真实 Rust 项目。
How to migrate gradually instead of attempting a reckless full rewrite
如何渐进式迁移，而不是头脑发热搞一次性重写。

Range 范围	Focus 重点	Outcome 阶段结果
Chapters 1-4 第 1-4 章	Motivation, setup, core syntax 动机、环境、基础语法	Can read and write small Rust programs 能够读写小型 Rust 程序。
Chapters 5-7 第 5-7 章	Data modeling and ownership 数据建模与所有权	Can explain moves, borrows, and `Option` 能够讲清 move、borrow 和 `Option`。
Chapters 8-10 第 8-10 章	Project structure, errors, traits 工程结构、错误、trait	Can organize multi-file crates and design APIs 能够组织多文件 crate 并设计基础 API。
Chapters 11-14 第 11-14 章	Conversions, iterators, async, FFI, testing 转换、迭代器、async、FFI、测试	Can build realistic services and tools 能够开始写接近真实项目的工具和服务。
Chapters 15-17 第 15-17 章	Migration, tooling, capstone 迁移、工具链、综合项目	Can plan a Java-to-Rust adoption path 能够设计一条从 Java 过渡到 Rust 的采用方案。