If you write Java against REST APIs, you have typed the same thing many times: copy a JSON response, then hand-write the classes that match it. For years the IntelliJ answer was GsonFormat, which generated old-style POJOs. It stopped working with current IDEs a while ago, and the popular JSON-to-class plugins I checked generate classes, not Java records, which is what you want for an immutable API payload in Java 16+.

So I built a small one: JSON to Java Record, now on the JetBrains Marketplace.

What it does

Copy this JSON:

{ "order_id": 10452, "created_at": "2026-11-08T14:03:00Z", "total": 129.95, "paid": true, "customer": { "id": 88, "full_name": "Ana Ruiz", "email": "ana@example.com" }, "items": [ { "sku": "KB-01", "qty": 1, "price": 89.0 }, { "sku": "MS-02", "qty": 2, "price": 20.475, "gift_wrap": true } ] }

Press Alt+Insert in a Java file, choose Paste JSON as Java Record... (also under Tools), name it Order, and you get this (the plugin's actual output; in the editor it is then reformatted with your own code style):

import java.util.List; public record Order( int orderId, String createdAt, double total, boolean paid, Customer customer, List<Item> items ) { public record Customer( int id, String fullName, String email ) {} public record Item( String sku, int qty, double price, Boolean giftWrap ) {} }

A few details that matter in real payloads:

  • Nested objects become nested records, and arrays of objects become List<...> of a record.
  • Arrays are merged. gift_wrap appears in only one of the two items, so it becomes a boxed Boolean (it can be null), while fields present everywhere stay primitive.
  • Numbers are typed sensibly: int, long for big values, double for decimals; a list mixing 1 and 2.5 becomes List<Double>.
  • snake_case becomes camelCase, and reserved words are made safe (class becomes class_).

Keep the original JSON names

If your mapper needs the original keys, pick Jackson or Gson in the dialog. Only the fields whose Java name differs get an annotation:

import com.fasterxml.jackson.annotation.JsonProperty; import java.util.List; public record Order( @JsonProperty("order_id") int orderId, @JsonProperty("created_at") String createdAt, double total, boolean paid, Customer customer, List<Item> items ) { public record Customer( int id, @JsonProperty("full_name") String fullName, String email ) {} public record Item( String sku, int qty, double price, @JsonProperty("gift_wrap") Boolean giftWrap ) {} }

Gson users get @SerializedName instead.

Where it puts the code

  • In an open Java file, it inserts at the caret (or replaces a selection), adds missing imports at the top and reformats.
  • From the Project view (right-click a package, New > Paste JSON as Java Record...), it creates Order.java there. It never overwrites an existing file.
  • Invalid JSON shows an error and changes nothing. It reads your clipboard, works offline and sends no telemetry.

Limits, honestly

  • IntelliJ IDEA 2025.2 or newer, with Java support. It does not run in PyCharm or WebStorm.
  • Types are inferred from the sample you paste. A field that is null in your sample becomes Object; paste a fuller sample or fix that one type by hand.
  • Dates stay String. Mapping them to Instant or LocalDate is your call.

Get it

It is a first version. If it gets a type wrong on your payload, or you want another output (Lombok, Kotlin data classes, TypeScript), open an issue or tell me in the comments.