org.springframework.core.type.classreading.AbstractRecursiveAnnotationVisitor Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or 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
*
* http://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 org.springframework.core.type.classreading;
import java.lang.reflect.Field;
import java.security.AccessControlException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.asm.AnnotationVisitor;
import org.springframework.asm.SpringAsmInfo;
import org.springframework.asm.Type;
import org.springframework.core.annotation.AnnotationAttributes;
import org.springframework.lang.Nullable;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
/**
* {@link AnnotationVisitor} to recursively visit annotations.
*
* @author Chris Beams
* @author Juergen Hoeller
* @author Phillip Webb
* @author Sam Brannen
* @since 3.1.1
*/
abstract class AbstractRecursiveAnnotationVisitor extends AnnotationVisitor {
protected final Log logger = LogFactory.getLog(getClass());
protected final AnnotationAttributes attributes;
@Nullable
protected final ClassLoader classLoader;
public AbstractRecursiveAnnotationVisitor(@Nullable ClassLoader classLoader, AnnotationAttributes attributes) {
super(SpringAsmInfo.ASM_VERSION);
this.classLoader = classLoader;
this.attributes = attributes;
}
@Override
public void visit(String attributeName, Object attributeValue) {
this.attributes.put(attributeName, attributeValue);
}
@Override
public AnnotationVisitor visitAnnotation(String attributeName, String asmTypeDescriptor) {
String annotationType = Type.getType(asmTypeDescriptor).getClassName();
AnnotationAttributes nestedAttributes = new AnnotationAttributes(annotationType, this.classLoader);
this.attributes.put(attributeName, nestedAttributes);
return new RecursiveAnnotationAttributesVisitor(annotationType, nestedAttributes, this.classLoader);
}
@Override
public AnnotationVisitor visitArray(String attributeName) {
return new RecursiveAnnotationArrayVisitor(attributeName, this.attributes, this.classLoader);
}
@Override
public void visitEnum(String attributeName, String asmTypeDescriptor, String attributeValue) {
Object newValue = getEnumValue(asmTypeDescriptor, attributeValue);
visit(attributeName, newValue);
}
protected Object getEnumValue(String asmTypeDescriptor, String attributeValue) {
Object valueToUse = attributeValue;
try {
Class enumType = ClassUtils.forName(Type.getType(asmTypeDescriptor).getClassName(), this.classLoader);
Field enumConstant = ReflectionUtils.findField(enumType, attributeValue);
if (enumConstant != null) {
ReflectionUtils.makeAccessible(enumConstant);
valueToUse = enumConstant.get(null);
}
}
catch (ClassNotFoundException | NoClassDefFoundError ex) {
logger.debug("Failed to classload enum type while reading annotation metadata", ex);
}
catch (IllegalAccessException | AccessControlException ex) {
logger.debug("Could not access enum value while reading annotation metadata", ex);
}
return valueToUse;
}
}