JarCastingAnnotationClaim
AnnotationClaim is a simple annotation processor for the Java compiler, which simply "claims" whichever annotations you specify. This makes it possible to avoid the javac Xlint warning: No processor claimed any of these annotations: org.example.Annotation when using javac's -Xlint option together with (a) other annotation processors and (b) other "runtime" annotations.
This is useful if you are trying to eliminate all compiler warnings, at least until https://bugs.openjdk.java.net/browse/JDK-6999068 is fixed.
Usage
Specify the annotation option org.zanata.annotationclaim.annotations with a list of annotation names you want to claim. For instance:
javac Example.java -processorpath annotationclaim.jar \
-Aorg.zanata.annotationclaim.annotations=org.junit.runner.RunWith,org.junit.Test
If you are using Maven or Gradle to compile, you may wish to use a project property to hold the list of annotations. You can separate multiple annotations with commas or whitespace characters, including newlines.
You can also specify the additional annotation org.zanata.annotationclaim.verbose=true to enable more logging. Note that this may trigger a minor but annoying warning bug in the compiler: https://bugs.openjdk.java.net/browse/JDK-8162455
How it works
AnnotationClaim will tell javac to send it whichever annotations you tell it. When javac comes across one of these annotations, it will pass it to AnnotationClaim, and AnnotationClaim will report to javac that the annotation has been claimed, ie processed. This will prevent the annotation from being seen by any other annotation processor, so make sure the annotation is not needed by your other annotation processors before telling AnnotationClaim to claim it. As long as every annotation has been claimed by an annotation processor, you should avoid the Xlint warning No processor claimed any of these annotations: org.example.Annotation.
Shortcomings
You have to list all of the runtime annotations for which you want to suppress the warning, and there are often a lot of them. It would be better if you could just list the small number of annotations which your other annotation processors want to use at compile time, but this would require AnnotationClaim to declare support for wildcard annotations, javac would pass all annotations on a code element to AnnotationClaim, and then AnnotationClaim could (a) claim them all (thus preventing other processors from working) or (b) not claim them all (thus failing to prevent the "No processor claimed..." warning).
Hard-coding a list of "runtime" annotations into AnnotationClaim would reduce the need for large lists, but would increase the maintenance burden of AnnotationClaim, and also increase the likelihood of blocking an important annotation. For instance, the annotation javax.annotation.Nullable is typically not used by any compile-time annotation processor, but this is not true for projects which use the Checker Framework's Nullness Checker.
Updating the annotation list
When javac outputs a warning for one or more new runtime annotations -
warning: No processor claimed any of these annotations: org.example.Annotation1,org.example.Annotation2
- you can just add the listed annotations to the
org.zanata.annotationclaim.annotationsparameter. But before you do, please make sure the annotations don't belong to a new annotation processor which you forgot to activate, or you will stop that other annotation processor from doing its job.
Example
# Compiling with an annotation processor, but without activating the AnnotationClaim processor:
$ javac src/main/java/org/zanata/annotationclaim/AnnotationClaim.java \
-Xlint -processorpath ~/.m2/repository/org/projectlombok/lombok/1.16.6/lombok-1.16.6.jar
warning: No processor claimed any of these annotations: javax.annotation.processing.SupportedOptions
1 warning
$
# With the AnnotationClaim processor activated:
$ javac src/main/java/org/zanata/annotationclaim/AnnotationClaim.java \
-Xlint -processorpath ~/.m2/repository/org/projectlombok/lombok/1.16.6/lombok-1.16.6.jar:build/libs/annotationclaim-1.0-SNAPSHOT.jar \
-Aorg.zanata.annotationclaim.annotations=javax.annotation.processing.SupportedOptions
$
More Details
See https://bugs.openjdk.java.net/browse/JDK-6999068 for more details about the javac warning.
Maven Example with Takari Lifecycle Plugin
Note that this does not work reliably for multi-module projects - for some reason takari-lifecycle-plugin seems to leave annotation processors like AnnotationClaim off the classpath when doing recursive builds.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
...
<properties>
<annotationclaim.annotations>
com.google.common.annotations.Beta
com.google.common.annotations.VisibleForTesting
com.google.gwt.user.client.rpc.RemoteServiceRelativePath
com.google.gwtmockito.GwtMock
com.tngtech.java.junit.dataprovider.DataProvider
com.tngtech.java.junit.dataprovider.UseDataProvider
edu.umd.cs.findbugs.annotations.SuppressFBWarnings
java.beans.ConstructorProperties
java.lang.FunctionalInterface
javax.annotation.CheckForNull
javax.annotation.Nonnull
javax.annotation.Nullable
javax.annotation.ParametersAreNonnullByDefault
javax.annotation.PostConstruct
javax.annotation.PreDestroy
javax.annotation.Priority
javax.annotation.Resource
javax.ejb.MessageDriven
javax.enterprise.context.ApplicationScoped
javax.enterprise.context.Dependent
javax.enterprise.context.RequestScoped
javax.enterprise.context.SessionScoped
javax.enterprise.event.Observes
javax.enterprise.inject.Alternative
javax.enterprise.inject.Any
javax.enterprise.inject.Default
javax.enterprise.inject.Disposes
javax.enterprise.inject.Model
javax.enterprise.inject.Produces
javax.enterprise.inject.Stereotype
javax.enterprise.util.Nonbinding
javax.faces.application.ResourceDependencies
javax.faces.bean.ViewScoped
javax.faces.component.FacesComponent
javax.faces.render.FacesRenderer
javax.inject.Inject
javax.inject.Named
javax.inject.Qualifier
javax.interceptor.AroundInvoke
javax.interceptor.Interceptor
javax.interceptor.InterceptorBinding
javax.persistence.Access
javax.persistence.Basic
javax.persistence.Cacheable
javax.persistence.Column
javax.persistence.DiscriminatorColumn
javax.persistence.DiscriminatorValue
javax.persistence.ElementCollection
javax.persistence.Embeddable
javax.persistence.EmbeddedId
javax.persistence.Entity
javax.persistence.EntityListeners
javax.persistence.Enumerated
javax.persistence.GeneratedValue
javax.persistence.Id
javax.persistence.IdClass
javax.persistence.Inheritance
javax.persistence.JoinColumn
javax.persistence.JoinTable
javax.persistence.Lob
javax.persistence.ManyToMany
javax.persistence.ManyToOne
javax.persistence.MapKey
javax.persistence.MapKeyColumn
javax.persistence.MapKeyEnumerated
javax.persistence.MapKeyJoinColumn
javax.persistence.MappedSuperclass
javax.persistence.NamedQueries
javax.persistence.OneToMany
javax.persistence.OneToOne
javax.persistence.OrderBy
javax.persistence.OrderColumn
javax.persistence.PersistenceUnit
javax.persistence.PostLoad
javax.persistence.PostPersist
javax.persistence.PostUpdate
javax.persistence.PrePersist
javax.persistence.PreRemove
javax.persistence.PreUpdate
javax.persistence.Table
javax.persistence.Temporal
javax.persistence.Transient
javax.persistence.Version
javax.servlet.annotation.WebFilter
javax.servlet.annotation.WebServlet
javax.validation.Constraint
javax.validation.constraints.NotNull
javax.validation.constraints.Pattern
javax.validation.constraints.Size
javax.ws.rs.ApplicationPath
javax.ws.rs.ConstrainedTo
javax.ws.rs.Consumes
javax.ws.rs.DELETE
javax.ws.rs.DefaultValue
javax.ws.rs.GET
javax.ws.rs.HeaderParam
javax.ws.rs.POST
javax.ws.rs.PUT
javax.ws.rs.Path
javax.ws.rs.PathParam
javax.ws.rs.Produces
javax.ws.rs.QueryParam
javax.ws.rs.container.PreMatching
javax.ws.rs.core.Context
javax.ws.rs.ext.Provider
javax.xml.bind.annotation.XmlAttribute
javax.xml.bind.annotation.XmlElement
javax.xml.bind.annotation.XmlElementRef
javax.xml.bind.annotation.XmlRootElement
javax.xml.bind.annotation.XmlType
org.apache.deltaspike.core.api.common.DeltaSpike
org.apache.deltaspike.core.api.exception.control.ExceptionHandler
org.apache.deltaspike.core.api.exception.control.Handles
org.apache.deltaspike.core.api.exclude.Exclude
org.apache.deltaspike.core.api.lifecycle.Destroyed
org.apache.deltaspike.core.api.lifecycle.Initialized
org.apache.deltaspike.core.api.scope.ConversationGroup
org.apache.deltaspike.core.api.scope.GroupedConversationScoped
org.apache.deltaspike.core.api.scope.WindowScoped
org.apache.deltaspike.jpa.api.transaction.Transactional
org.apache.deltaspike.jsf.api.listener.phase.JsfPhaseListener
org.apache.deltaspike.scheduler.api.Scheduled
org.apache.deltaspike.security.api.authorization.Secured
org.apache.deltaspike.security.api.authorization.Secures
org.apache.deltaspike.security.api.authorization.SecurityBindingType
org.codehaus.jackson.annotate.JsonIgnore
org.codehaus.jackson.annotate.JsonIgnoreProperties
org.codehaus.jackson.annotate.JsonProperty
org.codehaus.jackson.annotate.JsonPropertyOrder
org.codehaus.jackson.map.annotate.JsonSerialize
org.hibernate.annotations.AttributeAccessor
org.hibernate.annotations.BatchSize
org.hibernate.annotations.Cache
org.hibernate.annotations.Immutable
org.hibernate.annotations.ListIndexBase
org.hibernate.annotations.NaturalId
org.hibernate.annotations.Type
org.hibernate.annotations.TypeDef
org.hibernate.annotations.TypeDefs
org.hibernate.annotations.Where
org.hibernate.search.annotations.AnalyzerDefs
org.hibernate.search.annotations.AnalyzerDiscriminator
org.hibernate.search.annotations.ClassBridge
org.hibernate.search.annotations.Factory
org.hibernate.search.annotations.Field
org.hibernate.search.annotations.FieldBridge
org.hibernate.search.annotations.FullTextFilterDef
org.hibernate.search.annotations.Indexed
org.hibernate.search.annotations.IndexedEmbedded
org.hibernate.search.annotations.SortableField
org.hibernate.validator.constraints.Email
org.hibernate.validator.constraints.NotEmpty
org.jboss.arquillian.container.test.api.Deployment
org.jboss.arquillian.container.test.api.RunAsClient
org.jboss.arquillian.core.api.annotation.Inject
org.jboss.arquillian.core.api.annotation.Observes
org.jboss.arquillian.test.api.ArquillianResource
org.jboss.arquillian.test.spi.annotation.ClassScoped
org.jboss.arquillian.test.spi.annotation.TestScoped
org.jboss.resteasy.annotations.providers.jaxb.Wrapped
org.jboss.resteasy.annotations.providers.multipart.MultipartForm
org.jglue.cdiunit.AdditionalClasses
org.jglue.cdiunit.AdditionalClasspaths
org.jglue.cdiunit.InRequestScope
org.jglue.cdiunit.InSessionScope
org.jglue.cdiunit.ProducerConfig
org.jglue.cdiunit.ProducesAlternative
org.jglue.cdiunit.deltaspike.SupportDeltaspikeCore
org.junit.After
org.junit.AfterClass
org.junit.Before
org.junit.BeforeClass
org.junit.ClassRule
org.junit.Ignore
org.junit.Rule
org.junit.Test
org.junit.experimental.categories.Categories.IncludeCategory
org.junit.experimental.categories.Category
org.junit.runner.RunWith
org.junit.runners.Parameterized.Parameter
org.junit.runners.Parameterized.Parameters
org.junit.runners.Parameterized.UseParametersRunnerFactory
org.junit.runners.Suite.SuiteClasses
org.mockito.Captor
org.mockito.Mock
org.ocpsoft.rewrite.annotation.RewriteConfiguration
</annotationclaim.annotations>
</properties>
<build>
<plugins>
<plugin>
<groupId>io.takari.maven.plugins</groupId>
<artifactId>takari-lifecycle-plugin</artifactId>
<extensions>true</extensions>
<configuration>
<annotationProcessorOptions>
<org.zanata.annotationclaim.annotations>${annotationclaim.annotations}</org.zanata.annotationclaim.annotations>
</annotationProcessorOptions>
<proc>proc</proc>
</configuration>
<dependencies>
<dependency>
<groupId>org.zanata</groupId>
<artifactId>annotationclaim</artifactId>
<version>1.0</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
...
</project>
