io.micronaut.annotation.processing.LoadedVisitor Maven / Gradle / Ivy
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/*
* Copyright 2017-2020 original authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.micronaut.annotation.processing;
import io.micronaut.core.annotation.AnnotationMetadata;
import io.micronaut.core.annotation.Internal;
import io.micronaut.core.order.Ordered;
import io.micronaut.core.reflect.GenericTypeUtils;
import io.micronaut.inject.visitor.TypeElementVisitor;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.TypeMirror;
import java.util.Collections;
import java.util.List;
/**
* Used to store a reference to an underlying {@link TypeElementVisitor} and
* optionally invoke the visit methods on the visitor if it matches the
* element being visited by the annotation processor.
*
* @author James Kleeh
* @since 1.0
*/
@Internal
final class LoadedVisitor implements Ordered {
private static final String OBJECT_CLASS = Object.class.getName();
private final TypeElementVisitor visitor;
private final String classAnnotation;
private final String elementAnnotation;
/**
* @param visitor The {@link TypeElementVisitor}
* @param processingEnvironment The {@link ProcessingEnvironment}
*/
public LoadedVisitor(TypeElementVisitor visitor,
ProcessingEnvironment processingEnvironment) {
this.visitor = visitor;
Class aClass = visitor.getClass();
TypeElement typeElement = processingEnvironment.getElementUtils().getTypeElement(aClass.getName());
if (typeElement != null) {
List generics = interfaceGenericTypesFor(typeElement, TypeElementVisitor.class.getName());
if (generics.size() == 2) {
String typeName = generics.get(0).toString();
if (typeName.equals(OBJECT_CLASS)) {
classAnnotation = visitor.getClassType();
} else {
classAnnotation = typeName;
}
String elementName = generics.get(1).toString();
if (elementName.equals(OBJECT_CLASS)) {
elementAnnotation = visitor.getElementType();
} else {
elementAnnotation = elementName;
}
} else {
Class[] classes = GenericTypeUtils.resolveInterfaceTypeArguments(aClass, TypeElementVisitor.class);
if (classes != null && classes.length == 2) {
Class classGeneric = classes[0];
if (classGeneric == Object.class) {
classAnnotation = visitor.getClassType();
} else {
classAnnotation = classGeneric.getName();
}
Class elementGeneric = classes[1];
if (elementGeneric == Object.class) {
elementAnnotation = visitor.getElementType();
} else {
elementAnnotation = elementGeneric.getName();
}
} else {
classAnnotation = Object.class.getName();
elementAnnotation = Object.class.getName();
}
}
} else {
Class[] classes = GenericTypeUtils.resolveInterfaceTypeArguments(aClass, TypeElementVisitor.class);
if (classes != null && classes.length == 2) {
Class classGeneric = classes[0];
if (classGeneric == Object.class) {
classAnnotation = visitor.getClassType();
} else {
classAnnotation = classGeneric.getName();
}
Class elementGeneric = classes[1];
if (elementGeneric == Object.class) {
elementAnnotation = visitor.getElementType();
} else {
elementAnnotation = elementGeneric.getName();
}
} else {
classAnnotation = Object.class.getName();
elementAnnotation = Object.class.getName();
}
}
}
/**
* Finds the generic types for the given interface for the given class element.
*
* @param element The class element
* @param interfaceName The interface
* @return The generic types or an empty list
*/
private List interfaceGenericTypesFor(TypeElement element, String interfaceName) {
for (TypeMirror tm : element.getInterfaces()) {
DeclaredType declaredType = (DeclaredType) tm;
Element declaredElement = declaredType.asElement();
if (declaredElement instanceof TypeElement te) {
if (interfaceName.equals(te.getQualifiedName().toString())) {
return declaredType.getTypeArguments();
}
}
}
return Collections.emptyList();
}
@Override
public int getOrder() {
return visitor.getOrder();
}
/**
* @return The visitor
*/
public TypeElementVisitor getVisitor() {
return visitor;
}
/**
* @param annotationMetadata The annotation data
* @return True if the class element should be visited
*/
public boolean matchesClass(AnnotationMetadata annotationMetadata) {
if (classAnnotation.equals("java.lang.Object")) {
return true;
}
return annotationMetadata.hasStereotype(classAnnotation);
}
/**
* @param annotationMetadata The annotation data
* @return True if the element should be visited
*/
public boolean matchesElement(AnnotationMetadata annotationMetadata) {
if (elementAnnotation.equals("java.lang.Object")) {
return true;
}
return annotationMetadata.hasStereotype(elementAnnotation);
}
@Override
public String toString() {
return visitor.toString();
}
}