Java's Native JSON API: JDK 28 Gets Simpler

Java's JSON Future Takes Shape

JEP 540's proposal for a simple, built-in JSON API in JDK 28 is a welcome development for Java developers. The focus on core parsing, navigation, and generation without external dependencies directly addresses a long-standing gap in the JDK. Its immutability and thread-safety are excellent design choices, and the integration with pattern matching is a forward-thinking addition that will enhance code readability and robustness. The deliberate narrowing of scope, excluding complex features like data binding and streaming, is pragmatic, allowing for a focused and stable API that targets common use cases like configuration file parsing and REST response inspection. This approach reduces the barrier to entry and avoids the pitfalls of overly ambitious initial proposals.

However, the proposal's strictness, while ensuring interoperability and catching errors early, might be a double-edged sword. The rejection of comments, trailing commas, and duplicate object-member names, while technically compliant with RFC 8259's nuances, could lead to friction for developers accustomed to more lenient parsing modes found in popular libraries like Jackson or Gson. The explicit factory methods for JSON value construction, while clear, introduce a degree of ceremony that might feel verbose for simple JSON payloads, a point the article rightly identifies as a potential area for feedback. Developers will need to adapt to this new paradigm, and the incubation period will be crucial for gathering real-world feedback on these ergonomic and strictness trade-offs. The exclusion of advanced features like streaming and data binding means that for more complex scenarios, developers will still need to rely on existing robust libraries, making this a complementary rather than a complete replacement for the current ecosystem.

Key Points

• JEP 540, 'Simple JSON API (Incubator)', has moved to 'Proposed to Target' for JDK 28.
• It aims to provide a compact, JDK-native API for parsing, navigating, and generating RFC 8259 JSON.
• The API is deliberately narrow, excluding data binding and streaming, focusing on common tasks.
• Key design elements include an immutable, thread-safe JsonValue hierarchy and direct access methods for navigation.
• Strict parsing rejects comments, trailing commas, and duplicate object-member names.
• Construction uses explicit factory methods, which may add ceremony.
• The API integrates well with Java's pattern matching.
• It will ship in the incubating jdk.incubator.json module, allowing for feedback and potential changes.

---

📖 Source: JEP 540 Proposed to Target JDK 28 with a Simple JSON API