square/moshi
Moshi
Moshi is a JSON serialization library and parser for Kotlin and Java. It functions as a reflectionless JSON encoder that converts typed objects to JSON strings and parses JSON data back into language objects.
The library distinguishes itself through compile-time adapter generation, which removes the performance overhead associated with runtime reflection. It also provides a polymorphic JSON mapper that uses type identifiers to resolve and instantiate specific subclasses of a common base type.
The framework supports custom adapter definitions for specialized type conversion, including nullability constraint enforcement and contextual encoding via qualifiers. Its mapping capabilities cover field renaming, enum fallback management, property exclusion, and value class inlining. Additionally, it provides low-level streaming tools for raw value processing and non-destructive token peeking.
Features
- JSON Serialization Libraries - Functions as a high-performance library for converting Kotlin and Java objects to and from JSON.
- Compile-Time Code Generation - Produces optimized serialization logic at compile time to eliminate the performance overhead of runtime reflection.
- Custom Type Converters - Provides mechanisms to define specific logic for converting complex objects to control the resulting JSON string format.
- JSON Converters - Provides a framework for defining custom converters to handle specialized type transformations during JSON serialization.
- JSON-to-Model Mappers - Converts JSON strings into typed language objects by mapping keys to class fields.
- Custom Field Mapping - Provides customization of object field mapping to JSON keys using annotations to bridge naming conventions.
- JSON Parsers - Implements a JSON parser specifically optimized for Kotlin, supporting null safety and code generation.
- Reflectionless Encoders - Provides a reflectionless encoding mechanism using compile-time generated adapters for maximum performance.
- Type Safe Parsing - Ensures data integrity by mapping JSON input to strongly typed objects with strict nullability enforcement.
- JSON Serialization - Parses classes, primitives, and collections into JSON strings and back using built-in or generated logic.
- Adapter-Based Mapping - Implements a system of dedicated adapters to map JSON keys to class properties and vice versa.
- Reflectionless Serialization - Uses compile-time adapter generation to eliminate the performance costs associated with runtime reflection.
- Serialization Adapters - Provides modular components that encapsulate custom logic for converting specific data types during serialization.
- Contextual Serialization Rules - Uses qualifiers to apply different encoding rules to the same data type based on the specific field context.
- Data Parsing Utilities - Converts complex types like dates into standard objects using prebuilt adapters during the parsing process.
- Polymorphic Mapping - Embeds type identifiers in the JSON to resolve and instantiate specific subclasses of a common base type.
- Token-Based Stream Parsing - Reads JSON data as a sequence of tokens allowing for peek operations without consuming the underlying stream.
- Compositional Wrappers - Wraps existing adapters in modifiers to add behavioral logic like null safety or data transformation.
- Nullability Constraint Enforcement - Enables the creation of adapters that forbid nulls in the data body and fail immediately when encountered.
- Contextual Encoding Qualifiers - Uses qualifiers to apply different encoding rules to the same data type based on the specific field context.
- JSON Processing - Modern, unopinionated JSON library using standard Java types.
- Android Development Utilities - Modern JSON library for Android and Java.
- Data Serialization - Modern JSON library for Android and Java.
