Java Backend Technology
Feb 6, 2026 · Backend Development
What Breaking Changes Does Jackson 3 Introduce When Upgrading Spring Boot 4?
Upgrading to Spring Boot 4 brings Jackson 3, which reorganizes packages, replaces ObjectMapper with JsonMapper, changes the default date format to ISO‑8601, and converts checked exceptions to RuntimeException, requiring developers to adapt code, adjust configurations, and understand the design rationale to avoid runtime bugs.
Backend MigrationJackson 3Spring Boot
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