Back to index...

	/*
	* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package jdk.jfr;

	import java.lang.annotation.Annotation;
	import java.lang.reflect.Method;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Set;
	import java.util.StringJoiner;

	import jdk.jfr.internal.Type;
	import jdk.jfr.internal.TypeLibrary;
	import jdk.jfr.internal.Utils;

	/**
	* Describes event metadata, such as labels, descriptions and units.
	* <p>
	* The following example shows how {@code AnnotationElement} can be used to dynamically define events.
	*
	* <pre>
	* <code>
	* List{@literal <}AnnotationElement{@literal >} typeAnnotations = new ArrayList{@literal <}{@literal >}();
	* typeannotations.add(new AnnotationElement(Name.class, "com.example.HelloWorld");
	* typeAnnotations.add(new AnnotationElement(Label.class, "Hello World"));
	* typeAnnotations.add(new AnnotationElement(Description.class, "Helps programmer getting started"));
	*
	* List{@literal <}AnnotationElement{@literal >} fieldAnnotations = new ArrayList{@literal <}{@literal >}();
	* fieldAnnotations.add(new AnnotationElement(Label.class, "Message"));
	*
	* List{@literal <}ValueDescriptor{@literal >} fields = new ArrayList{@literal <}{@literal >}();
	* fields.add(new ValueDescriptor(String.class, "message", fieldAnnotations));
	*
	* EventFactory f = EventFactory.create(typeAnnotations, fields);
	* Event event = f.newEvent();
	* event.commit();
	* </code>
	* </pre>
	*
	* @since 8
	*/
	public final class AnnotationElement {
	private final Type type;
	private final List<Object> annotationValues;
	private final List<String> annotationNames;
	private final boolean inBootClassLoader;

	// package private
	AnnotationElement(Type type, List<Object> objects, boolean boot) {
	Objects.requireNonNull(type);
	Objects.requireNonNull(objects);
	this.type = type;
	if (objects.size() != type.getFields().size()) {
	StringJoiner descriptors = new StringJoiner(",", "[", "]");
	for (ValueDescriptor v : type.getFields()) {
	descriptors.add(v.getName());
	}
	StringJoiner values = new StringJoiner(",", "[", "]");
	for (Object object : objects) {
	descriptors.add(String.valueOf(object));
	}
	throw new IllegalArgumentException("Annotation " + descriptors + " for " + type.getName() + " doesn't match number of values " + values);
	}

	List<String> n = new ArrayList<>();
	List<Object> v = new ArrayList<>();
	int index = 0;
	for (ValueDescriptor valueDescriptor : type.getFields()) {
	Object object = objects.get(index);
	if (object == null) {
	throw new IllegalArgumentException("Annotation value can't be null");
	}
	Class<?> valueType = object.getClass();
	if (valueDescriptor.isArray()) {
	valueType = valueType.getComponentType();
	}
	checkType(Utils.unboxType(valueType));
	n.add(valueDescriptor.getName());
	v.add(object);
	index++;
	}
	this.annotationValues = Utils.smallUnmodifiable(v);
	this.annotationNames = Utils.smallUnmodifiable(n);
	this.inBootClassLoader = boot;
	}

	/**
	* Creates an annotation element to use for dynamically defined events.
	* <p>
	* Supported value types are {@code byte}, {@code int}, {@code short},
	* {@code long}, {@code double}, {@code float}, {@code boolean}, {@code char},
	* and {@code String}. Enums, arrays and classes, are not supported.
	* <p>
	* If {@code annotationType} has annotations (directly present, indirectly
	* present, or associated), then those annotation are recursively included.
	* However, both the {@code annotationType} and any annotation found recursively
	* must have the {@link MetadataDefinition} annotation.
	* <p>
	* To statically define events, see {@link Event} class.
	*
	* @param annotationType interface extending
	* {@code java.lang.annotation.Annotation}, not {@code null}
	* @param values a {@code Map} with keys that match method names of the specified
	* annotation interface
	* @throws IllegalArgumentException if value/key is {@code null}, an unsupported
	* value type is used, or a value/key is used that doesn't match the
	* signatures in the {@code annotationType}
	*/
	public AnnotationElement(Class<? extends Annotation> annotationType, Map<String, Object> values) {
	Objects.requireNonNull(annotationType);
	Objects.requireNonNull(values);
	Utils.checkRegisterPermission();
	// copy values to avoid modification after validation
	HashMap<String, Object> map = new HashMap<>(values);
	for (Map.Entry<String, Object> entry : map.entrySet()) {
	if (entry.getKey() == null) {
	throw new NullPointerException("Name of annotation method can't be null");
	}
	if (entry.getValue() == null) {
	throw new NullPointerException("Return value for annotation method can't be null");
	}
	}

	if (AnnotationElement.class.isAssignableFrom(annotationType) && annotationType.isInterface()) {
	throw new IllegalArgumentException("Must be interface extending " + Annotation.class.getName());
	}
	if (!isKnownJFRAnnotation(annotationType) && annotationType.getAnnotation(MetadataDefinition.class) == null) {
	throw new IllegalArgumentException("Annotation class must be annotated with jdk.jfr.MetadataDefinition to be valid");
	}
	if (isKnownJFRAnnotation(annotationType)) {
	this.type = new Type(annotationType.getCanonicalName(), Type.SUPER_TYPE_ANNOTATION, Type.getTypeId(annotationType));
	} else {
	this.type = TypeLibrary.createAnnotationType(annotationType);
	}
	Method[] methods = annotationType.getDeclaredMethods();
	if (methods.length != map.size()) {
	throw new IllegalArgumentException("Number of declared methods must match size of value map");
	}
	List<String> n = new ArrayList<>();
	List<Object> v = new ArrayList<>();
	Set<String> nameSet = new HashSet<>();
	for (Method method : methods) {
	String fieldName = method.getName();
	Object object = map.get(fieldName);
	if (object == null) {
	throw new IllegalArgumentException("No method in annotation interface " + annotationType.getName() + " matching name " + fieldName);
	}
	Class<?> fieldType = object.getClass();

	if (fieldType == Class.class) {
	throw new IllegalArgumentException("Annotation value for " + fieldName + " can't be class");
	}
	if (object instanceof Enum) {
	throw new IllegalArgumentException("Annotation value for " + fieldName + " can't be enum");
	}
	if (!fieldType.equals(object.getClass())) {
	throw new IllegalArgumentException("Return type of annotation " + fieldType.getName() + " must match type of object" + object.getClass());
	}

	if (fieldType.isArray()) {
	Class<?> componentType = fieldType.getComponentType();
	checkType(componentType);
	if (componentType.equals(String.class)) {
	String[] stringArray = (String[]) object;
	for (int i = 0; i < stringArray.length; i++) {
	if (stringArray[i] == null) {
	throw new IllegalArgumentException("Annotation value for " + fieldName + " contains null");
	}
	}
	}
	} else {
	fieldType = Utils.unboxType(object.getClass());
	checkType(fieldType);
	}
	if (nameSet.contains(fieldName)) {
	throw new IllegalArgumentException("Value with name '" + fieldName + "' already exists");
	}
	if (isKnownJFRAnnotation(annotationType)) {
	ValueDescriptor vd = new ValueDescriptor(fieldType, fieldName, Collections.emptyList(), true);
	type.add(vd);
	}
	n.add(fieldName);
	v.add(object);
	}
	this.annotationValues = Utils.smallUnmodifiable(v);
	this.annotationNames = Utils.smallUnmodifiable(n);
	this.inBootClassLoader = annotationType.getClassLoader() == null;
	}

	/**
	* Creates an annotation element to use for dynamically defined events.
	* <p>
	* Supported value types are {@code byte}, {@code int}, {@code short},
	* {@code long}, {@code double}, {@code float}, {@code boolean}, {@code char},
	* and {@code String}. Enums, arrays, and classes are not supported.
	* <p>
	* If {@code annotationType} has annotations (directly present, indirectly
	* present, or associated), then those annotations are recursively included.
	* However, both {@code annotationType} and any annotation found recursively
	* must have the {@link MetadataDefinition} annotation.
	* <p>
	* To statically define events, see {@link Event} class.
	*
	* @param annotationType interface extending
	* {@code java.lang.annotation.Annotation,} not {@code null}
	* @param value the value that matches the {@code value} method of the specified
	* {@code annotationType}
	* @throws IllegalArgumentException if value/key is {@code null}, an unsupported
	* value type is used, or a value/key is used that doesn't match the
	* signatures in the {@code annotationType}
	*/
	public AnnotationElement(Class<? extends Annotation> annotationType, Object value) {
	this(annotationType, Collections.singletonMap("value", Objects.requireNonNull(value)));
	}

	/**
	* Creates an annotation element to use for dynamically defined events.
	* <p>
	* Supported value types are {@code byte}, {@code short}, {@code int},
	* {@code long}, {@code double}, {@code float}, {@code boolean}, {@code char},
	* and {@code String}. Enums, arrays, and classes are not supported.
	* <p>
	* If {@code annotationType} has annotations (directly present, indirectly
	* present or associated), then those annotation are recursively included.
	* However, both {@code annotationType} and any annotation found recursively
	* must have the {@link MetadataDefinition} annotation.
	* <p>
	* To statically define events, see {@link Event} class.
	*
	* @param annotationType interface extending java.lang.annotation.Annotation,
	* not {@code null}
	*/
	public AnnotationElement(Class<? extends Annotation> annotationType) {
	this(annotationType, Collections.emptyMap());
	}

	/**
	* Returns an immutable list of annotation values in an order that matches the
	* value descriptors for this {@code AnnotationElement}.
	*
	* @return list of values, not {@code null}
	*/
	public List<Object> getValues() {
	return annotationValues;
	}

	/**
	* Returns an immutable list of descriptors that describes the annotation values
	* for this {@code AnnotationElement}.
	*
	* @return the list of value descriptors for this {@code Annotation}, not
	* {@code null}
	*/
	public List<ValueDescriptor> getValueDescriptors() {
	return Collections.unmodifiableList(type.getFields());
	}

	/**
	* Returns an immutable list of annotation elements for this
	* {@code AnnotationElement}.
	*
	* @return a list of meta annotation, not {@code null}
	*/
	public List<AnnotationElement> getAnnotationElements() {
	return type.getAnnotationElements();
	}

	/**
	* Returns the fully qualified name of the annotation type that corresponds to
	* this {@code AnnotationElement} (for example, {@code "jdk.jfr.Label"}).
	*
	* @return type name, not {@code null}
	*/
	public String getTypeName() {
	return type.getName();
	}

	/**
	* Returns a value for this {@code AnnotationElement}.
	*
	* @param name the name of the method in the annotation interface, not
	* {@code null}.
	*
	* @return the annotation value, not {@code null}.
	*
	* @throws IllegalArgumentException if a method with the specified name does
	* not exist in the annotation
	*/
	public Object getValue(String name) {
	Objects.requireNonNull(name);
	int index = 0;
	for (String n : annotationNames) {
	if (name.equals(n)) {
	return annotationValues.get(index);
	}
	index++;
	}
	StringJoiner valueNames = new StringJoiner(",", "[", "]");
	for (ValueDescriptor v : type.getFields()) {
	valueNames.add(v.getName());
	}
	throw new IllegalArgumentException("No value with name '" + name + "'. Valid names are " + valueNames);
	}

	/**
	* Returns {@code true} if an annotation value with the specified name exists in
	* this {@code AnnotationElement}.
	*
	* @param name name of the method in the annotation interface to find, not
	* {@code null}
	*
	* @return {@code true} if method exists, {@code false} otherwise
	*/
	public boolean hasValue(String name) {
	Objects.requireNonNull(name);
	for (String n : annotationNames) {
	if (name.equals(n)) {
	return true;
	}
	}
	return false;
	}

	/**
	* Returns the first annotation for the specified type if an
	* {@code AnnotationElement} with the same name exists, else {@code null}.
	*
	* @param <A> the type of the annotation to query for and return if it exists
	* @param annotationType the {@code Class object} corresponding to the annotation type,
	* not {@code null}
	* @return this element's annotation for the specified annotation type if
	* it it exists, else {@code null}
	*/
	public final <A> A getAnnotation(Class<? extends Annotation> annotationType) {
	Objects.requireNonNull(annotationType);
	return type.getAnnotation(annotationType);
	}

	/**
	* Returns the type ID for this {@code AnnotationElement}.
	* <p>
	* The ID is a unique identifier for the type in the Java Virtual Machine (JVM). The ID might not
	* be the same between JVM instances.
	*
	* @return the type ID, not negative
	*/
	public long getTypeId() {
	return type.getId();
	}

	// package private
	Type getType() {
	return type;
	}

	private static void checkType(Class<?> type) {
	if (type.isPrimitive()) {
	return;
	}
	if (type == String.class) {
	return;
	}
	throw new IllegalArgumentException("Only primitives types or java.lang.String are allowed");
	}

	// Whitelist of annotation classes that are allowed, even though
	// they don't have @MetadataDefinition.
	private static boolean isKnownJFRAnnotation(Class<? extends Annotation> annotationType) {
	if (annotationType == Registered.class) {
	return true;
	}
	if (annotationType == Threshold.class) {
	return true;
	}
	if (annotationType == StackTrace.class) {
	return true;
	}
	if (annotationType == Period.class) {
	return true;
	}
	if (annotationType == Enabled.class) {
	return true;
	}
	return false;
	}

	// package private
	boolean isInBoot() {
	return inBootClassLoader;
	}

	}

Back to index...