About Java to JSON Serialization

Converting Java objects to JSON is a fundamental operation in modern Java development, especially when building REST APIs, microservices, and web applications. This tool simulates how popular Java libraries like Jackson and Gson serialize Java POJOs (Plain Old Java Objects) into JSON format. Simply paste your Java class definition, and the tool will generate the corresponding JSON representation with sample values.

• Parses Java class fields and data types automatically
• Generates realistic sample JSON values
• Supports Jackson, Gson, and standard JSON serialization
• Handles nested objects and collections (List, Set, Map)
• Respects annotations like @JsonProperty and @SerializedName

How This Tool Helps You

This online Java to JSON converter helps developers quickly visualize how their Java objects will be serialized without writing test code or running a Java application. Perfect for API documentation, testing JSON structure before implementation, understanding serialization behavior, and creating sample payloads for frontend developers. The tool intelligently generates realistic sample data based on field names and types, making it easy to see exactly what your API responses will look like.

Choose between different serialization libraries to see how Jackson, Gson, or standard JSON would handle your objects. Enable pretty-print for readable output, toggle null values, and customize field naming conventions (camelCase vs snake_case). The tool supports common Java types including primitives, wrapper classes, Collections (List, Set, Map), nested objects, and even recognizes common patterns like User, Person, Product to generate more realistic test data.