Spring Boot 3 升级指南：从 2.x 迁移要注意什么
Spring Boot 3 Upgrade Guide — What to Watch When Migrating from 2.x
| iDev Team | 2026-08-13T09:46:24
Jakarta EE 命名空间变更、Java 17 最低要求、Spring Security 重构——Spring Boot 3 迁移的关键变化和避坑指南。
Jakarta EE namespace changes, Java 17 minimum requirement, Spring Security overhaul — key changes and pitfalls when migrating to Spring Boot 3.
为什么要升级Spring Boot 2.x 已进入维护模式，不再有新功能更新。Spring Boot 3 带来了 Java 17+ 支持、GraalVM 原生编译、更好的性能。如果你的项目还在 2.x，现在是升级的好时机。三大核心变化1. javax → jakarta这是最大的破坏性变更。所有 javax.* 包名改为 jakarta.*。影响范围：Servlet API、JPA、Validation、Mail 等。IDE 的全局替换可以解决大部分，但第三方库的兼容性需要逐个检查。2. Java 17 最低要求Spring Boot 3 不再支持 Java 8/11。必须升级到 Java 17+。好消息是 Java 17 是 LTS 版本，Records、Sealed Classes、Text Blocks 等新特性让代码更简洁。3. Spring Security 6 重构WebSecurityConfigurerAdapter 被移除，改用 SecurityFilterChain Bean 的方式配置。如果你的项目用了 Spring Security，这部分改动量最大。迁移步骤建议先升级 Java 到 17把 Spring Boot 升到 2.7（最后的 2.x 版本，提供了迁移提示）用 OpenRewrite 自动迁移 javax → jakarta逐个处理编译错误跑测试，重点关注 Security 相关
Why UpgradeSpring Boot 2.x is in maintenance mode with no new features. Spring Boot 3 brings Java 17+ support, GraalVM native compilation, and better performance. If your project is still on 2.x, now is a good time to upgrade.Three Core Changes1. javax → jakartaThe biggest breaking change. All javax.* packages renamed to jakarta.*. Affects: Servlet API, JPA, Validation, Mail, etc. IDE global replace handles most cases, but third-party library compatibility needs individual verification.2. Java 17 Minimum RequirementSpring Boot 3 drops Java 8/11 support. Must upgrade to Java 17+. Good news: Java 17 is LTS, and features like Records, Sealed Classes, and Text Blocks make code more concise.3. Spring Security 6 OverhaulWebSecurityConfigurerAdapter is removed, replaced by SecurityFilterChain Bean configuration. If your project uses Spring Security, this is the most significant change.Migration StepsUpgrade Java to 17 firstUpgrade Spring Boot to 2.7 (last 2.x version, provides migration hints)Use OpenRewrite to auto-migrate javax → jakartaHandle compilation errors one by oneRun tests, focus on Security-related areas