Proto

Annotation Processor Tools

About

This is a collection of classes that helps with writing Java Annotation Processors. There are 3 min points this project provides

• Verification of annotated elements
• Logging at compile time
• A bugfix for a bug in the Java compiler AP API [JDK-8256826] Source generated in last round not visible to other sources - Java Bug System

Usage

When writing an annotation processor the base class to use is BaseProcessor.

When doing so you will have two fields

• logger
• verifier

that provide high level access to the java processing API.

The bugfix mentioned above will automatically be applied to your project if you don' t disable it manually.

To generate classes it is highly recommended to use JavaPoet (included,Introduction to JavaPoet | Baeldung) and the writeClass() method.

Examples

verifier.isClass(someElement)
    .because("only classes can be mapped")
    .failOnViolation();

java: error someElement should be a class, because only classes can be mapped

verifier.isAnnotated(someElement, Override.class)
    .because("only overriden methods can be compile time mocked")
    .failOnViolation();

java: error someElement should be annotated with @Override, because only overriden methods can be compile time mocked

verifier.doesExtend(myElement, Serializable.class)
    .not()
    .because("Serializable is not state of the art")
    .warnOnViolation();

java: warning myElement should not extend Serializable, because Serializable is not state of the art