Java Annotation Processing Tool (APT)
The Java Annotation Processing Tool (APT) is a tool that allows developers to process Java annotations at compile-time. It enables the generation of new source files, configuration files, or other files based on the annotations present in the source code. APT is used to automatically generate code or configuration, reducing the amount of manual coding and ensuring consistency across large projects.
Introduced in Java 2006 with Java 6, APT allows developers to write custom processors that operate on the annotations found in Java source files. This tool is especially useful for frameworks, libraries, and other tools that need to generate code or configuration dynamically based on annotations, such as in Java's JPA (Java Persistence API) or Spring framework.
APT works by providing an interface for annotation processors that are run during the compilation process. These processors can inspect, process, and generate code or files based on annotations found in source files. This feature has become a cornerstone of modern Java development, enabling code generation and simplifying the development of complex systems.
By automating repetitive tasks, Java Annotation Processing helps streamline the development process and ensures that code is consistent with predefined annotations. This is particularly beneficial in large projects with many dependencies or custom configurations. More information about APT can be found in the official Java documentation.
https://docs.oracle.com/javase/8/docs/api/javax/annotation/processing/package-summary.html