Annotation Processor Tools
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
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.
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