com.google.auto.common

Class BasicAnnotationProcessor

java.lang.Object

javax.annotation.processing.AbstractProcessor

com.google.auto.common.BasicAnnotationProcessor

All Implemented Interfaces:

Processor

public abstract class BasicAnnotationProcessor
extends AbstractProcessor

An abstract Processor implementation that ensures that top-level Element instances are well-formed before attempting to perform processing on any of their children. In the event that they are not, the element will be enqueued for processing in a subsequent round. This ensures that processors will avoid many common pitfalls like ErrorType instances, ClassCastExceptions and badly coerced types.

The primary disadvantage to this processor is that any Element that forms a circular dependency with a type generated by a subclass of this processor will never compile because the given Element will never be fully complete. All such compilations will fail with an error message on the offending type that describes the issue.

Subclasses should put their processing logic in BasicAnnotationProcessor.ProcessingStep implementations. The steps are passed to the processor by returning them in the initSteps() method - access the ProcessingEnvironment using AbstractProcessor.processingEnv. Finally, any logic that needs to happen once per round can be specified by overriding postProcess().

Author:

Gregory Kick

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	BasicAnnotationProcessor.ProcessingStep The unit of processing logic that runs under the guarantee that all elements are complete and well-formed.

Field Summary

Fields inherited from class javax.annotation.processing.AbstractProcessor

processingEnv

Constructor Summary

Constructors

Constructor and Description
BasicAnnotationProcessor()

Method Summary

Methods

Modifier and Type	Method and Description
com.google.common.collect.ImmutableSet<String>	getSupportedAnnotationTypes() Returns the set of supported annotation types as a collected from registered processing steps.
void	init(ProcessingEnvironment processingEnv)
protected abstract Iterable<? extends BasicAnnotationProcessor.ProcessingStep>	initSteps() The mechanism by which processing steps are associated with the processor.
protected void	postProcess() An optional hook for logic to be executed at the end of each round.
boolean	process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv)

Methods inherited from class javax.annotation.processing.AbstractProcessor

getCompletions, getSupportedOptions, getSupportedSourceVersion, isInitialized

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BasicAnnotationProcessor

public BasicAnnotationProcessor()

Method Detail

init

public final void init(ProcessingEnvironment processingEnv)

Specified by:

init in interface Processor

Overrides:

init in class AbstractProcessor

initSteps

protected abstract Iterable<? extends BasicAnnotationProcessor.ProcessingStep> initSteps()

The mechanism by which processing steps are associated with the processor. #processinEnv is guaranteed to be set when this method is invoked.

postProcess

protected void postProcess()

An optional hook for logic to be executed at the end of each round.

getSupportedAnnotationTypes

public final com.google.common.collect.ImmutableSet<String> getSupportedAnnotationTypes()

Returns the set of supported annotation types as a collected from registered processing steps.

Specified by:

getSupportedAnnotationTypes in interface Processor

Overrides:

getSupportedAnnotationTypes in class AbstractProcessor

process

public final boolean process(Set<? extends TypeElement> annotations,
              RoundEnvironment roundEnv)

Specified by:

process in interface Processor

Specified by:

process in class AbstractProcessor