What Java types are generated?

Strings become String, integers become long, floats become double, booleans become boolean, and null values become Object. Nested objects become separate class types with PascalCase names. Arrays become List .

How are Jackson annotations added?

Each field gets a @JsonProperty("originalKey") annotation from Jackson. Field names are converted to camelCase. This preserves the original JSON key mapping while following Java naming conventions.

How are optional fields handled?

Fields that are missing from some items in an array are marked with @Nullable. This is compatible with Java's null safety annotations and signals to the developer that the field may be null.

DevBento

Tools/JSON to TypeScript & 8+ Languages Generator/Generate Java Classes from API Response

Generate Java Classes from API Response

Generate Java classes with Jackson annotations from a typical REST API JSON response. Paste your API JSON and get production-ready typed Java class files.

Output

Root name

Import path

JSON Input

TypeScript Output

// Generated by DevBento — json-to-typescript
interface RootAddress {
  street: string;
  city: string;
  zip: string;
}

interface RootPostsItem {
  title: string;
  likes?: number;
}

interface Root {
  id: number;
  name: string;
  email: string;
  isActive: boolean;
  roles: string[];
  address: RootAddress;
  posts: RootPostsItem[];
}

Send to:

Paste JSON to pretty-print, minify, validate, or visualize as an interactive graph. Syntax highlighting, tree view, and graph view with export.

ymlJSON / YAML / TOML / CSV / XML / HTML / Markdown

Convert between JSON, YAML, TOML, CSV, XML, HTML, Markdown, and .env in your browser. Paste config or API data and get the equivalent format instantly.

Generate Java Classes from API Response

This example generates Java classes with Jackson annotations from a typical REST API response. The pre-filled JSON represents a user object with nested address, array of roles, and array of post objects. Switch to Java mode to see the generated classes.

What You Get

The tool produces:

A root Root class with all fields
RootUser class for the nested address object
RootPostsItem class for array items
@JsonProperty("key") annotations on every field
camelCase field names following Java conventions
@Nullable annotations for optional fields
Java type mappings: String, long, double, boolean, List<String>

How to Use

The example loads with a sample API response and Java mode pre-selected
Inspect the generated Java classes and their Jackson annotations
Copy the classes and paste them into your Java project
Replace with your actual API response to generate classes for your endpoints

Real-World Pattern

Java classes with Jackson annotations are the standard way to deserialize API responses in Spring Boot and other Java frameworks. The generated code works directly with objectMapper.readValue(json, Root.class). Use @Nullable for fields that may not always be present in the response.

🔒

Nothing you paste leaves this tab. Every tool runs entirely in your browser — no upload, no server, no account.