This guide is for people proficient in APT. Other guides are available.

This project wraps and extends the Java APT API. It also adds a source file DSL API.

The Java APT API has two partially overlapping data structures: javax.lang.model.element and javax.lang.model.type, with the conversion from element to type being lossy. This project provides one unified data structure, resulting in a single representation of a type.

Declared types are separated into Annotation, Enum, Interface, Class and Record. Executables are separated into Constructor and Method.

TypeParameter/TypeVariable and IntersectionType are combined into Generic.

Methods from javax.lang.model.util.Elements and javax.lang.model.util.Types are moved to the respective Types when apropiate. This way javax.lang.model.util.Elements.overrides becomes Method#overrides and Method#overridenBy.

are combined to one Context

The Source File DSL simplifies generation. It starts with Copyright Headers and supports everything up to method parameters - including lesser known Java features like bidirectional generics or receiver types.

Supports iterating over the properties of a class as defined by the JavaBeans 1.01 specification. A property consists of:

The more comprehensive data structure allows methods to exist only on the specific leaf types. For example, it is not possible to check whether an enum is a functional interface or whether it has type parameters.

For invalid arguments, the Java APT API may return null, throw exceptions or return TypeKind.NONE. This API uses Optional and is null safe.

The generation of Typesafe Annotation Mirrors is possible using com.derivandi.api.generate.GenerateTypesafeUsage

The com.derivandi.api.processor.ProcessorBuilder guides when writing an Annotation Processor with sensible defaults.

Both just work out of the box.

Processor specific Exception handling and usage of the proper logging APIs is recommended.

There are Adapters for every conversion. You can use any other APT Tooling in addition to this library.