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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
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*
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package fish.payara.microprofile.metrics.cdi;
import jakarta.enterprise.inject.Stereotype;
import jakarta.enterprise.inject.spi.Annotated;
import jakarta.enterprise.inject.spi.AnnotatedMember;
import jakarta.enterprise.inject.spi.AnnotatedParameter;
import jakarta.enterprise.inject.spi.InjectionPoint;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Constructor;
import java.lang.reflect.Executable;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Predicate;
import org.eclipse.microprofile.metrics.Metadata;
import org.eclipse.microprofile.metrics.MetricID;
import org.eclipse.microprofile.metrics.MetricRegistry;
import org.eclipse.microprofile.metrics.MetricUnits;
import org.eclipse.microprofile.metrics.Tag;
import org.eclipse.microprofile.metrics.annotation.Counted;
import org.eclipse.microprofile.metrics.annotation.Gauge;
import org.eclipse.microprofile.metrics.annotation.Metric;
import org.eclipse.microprofile.metrics.annotation.Timed;
import static java.util.Arrays.asList;
/**
* Utility that allows reading the different MP metrics {@link Annotation}s from different annotated abstractions
* providing a common interface to allow generic handling and a common logic independent of the source of the
* {@link Annotation}.
*
* Supported are:
*
* - {@link AnnotatedElement}
* - {@link Annotated}
* - {@link InjectionPoint}
*
*
* It is important to realise that {@link Annotated} and {@link InjectionPoint} have to be used as a source when
* available as they allow to add or remove {@link Annotation} effectively acting as a runtime override of the compiled
* information provided by {@link AnnotatedElement}.
*
* This utility also encodes most of the logic as defined by the MP Metrics specification. This includes the logic of
* which annotation applied and how the metrics effective name if computed from annotation values and the annotated
* element. For this reason the methods are documented in great detail.
*
* @author Jan Bernitt
* @since 5.202
*
* @param Type of the MP metrics annotation
*/
public final class AnnotationReader {
/**
* Get {@link AnnotationReader} for a provided {@link Annotation}.
*
* @param annotationType
* @return The {@link AnnotationReader} for the provided {@link Annotation} type
* @throws IllegalAccessException In case no such reader exists
*/
@SuppressWarnings("unchecked")
public static AnnotationReader forAnnotation(Class annotationType) {
AnnotationReader reader = READERS_BY_ANNOTATION.get(annotationType);
if (reader == null) {
throw new IllegalArgumentException("Unsupported Metrics [" + annotationType.getName() + "]");
}
return (AnnotationReader) reader;
}
/**
* @return all available {@link AnnotationReader}s
*/
public static Iterable> readers() {
return READERS_BY_ANNOTATION.values();
}
private static final Map, AnnotationReader> READERS_BY_ANNOTATION = new HashMap<>();
public static final AnnotationReader COUNTED = new AnnotationReader<>(
Counted.class, Counted.class.getName(),
Counted::name,
Counted::tags,
Counted::description,
Counted::absolute,
Counted::unit,
Counted::scope);
public static final AnnotationReader GAUGE = new AnnotationReader<>(
Gauge.class, Gauge.class.getName(),
Gauge::name,
Gauge::tags,
Gauge::description,
Gauge::absolute,
Gauge::unit,
Gauge::scope);
public static final AnnotationReader TIMED = new AnnotationReader<>(
Timed.class, Timed.class.getName(),
Timed::name,
Timed::tags,
Timed::description,
Timed::absolute,
Timed::unit,
Timed::scope);
public static final AnnotationReader METRIC = new AnnotationReader<>(
Metric.class, Metric.class.getName(),
Metric::name,
Metric::tags,
Metric::description,
Metric::absolute,
Metric::unit,
Metric::scope);
private static void register(AnnotationReader reader) {
READERS_BY_ANNOTATION.put(reader.annotationType(), reader);
}
static {
register(COUNTED);
register(GAUGE);
register(TIMED);
register(METRIC);
}
private final Class annotationType;
private final String nameType;
private final Function name;
private final Function tags;
private final Function description;
private final Predicate absolute;
private final Function unit;
private final Function scope;
private AnnotationReader(Class annotationType, String nameType,
Function name,
Function tags,
Function description,
Predicate absolute,
Function unit, Function scope) {
this.annotationType = annotationType;
this.nameType = nameType;
this.name = name;
this.tags = tags;
this.description = description;
this.absolute = absolute;
this.unit = unit;
this.scope = scope;
}
public Class annotationType() {
return annotationType;
}
/**
* If this {@link AnnotationReader} reads {@link Metric} {@link Annotation} it can be associated with different
* metric class name type using the {@link AnnotationReader}.
*
* @param nameType String representing the type class of the metric
* @return A new {@link AnnotationReader} using the provided
* @throws IllegalStateException In case this method is called on {@link AnnotationReader} that is not reading
* {@link Metric} {@link Annotation}.
*/
public AnnotationReader asType(String nameType) {
if (this.annotationType != Metric.class) {
throw new IllegalStateException("Only Metric reader can be typed!");
}
return new AnnotationReader<>(annotationType, nameType, name, tags, description, absolute, unit, scope);
}
/**
* Infers the {@link org.eclipse.microprofile.metrics.Metric} {@link Class}, from the provided generic Type
*
* @param genericType the actual type of the {@link org.eclipse.microprofile.metrics.Metric} as declared by a
* {@link Member} or {@link Parameter}.
* @return A new {@link AnnotationReader} which uses the inferred
* @throws IllegalArgumentException in case the given type does not implement any of the known metric types.
*/
private AnnotationReader asType(Type genericType) {
Class type = (Class) (genericType instanceof Class
? genericType
: ((java.lang.reflect.ParameterizedType) genericType).getRawType());
return asType(type.getName());
}
private AnnotationReader asAutoType(Type genericType) {
return annotationType == Metric.class ? asType(genericType) : this;
}
/**
* Returns the effective annotation for the provided bean and element.
*
* @param bean type of the bean that declared the provided element
* @param element a {@link AnnotatedElement} possibly annotated with this {@link AnnotationReader}'s
* {@link #annotationType()}
* @return the effective {@link Annotation}, or {@code null}. The element's annotations take precedence over the
* bean's annotations.
*/
public T annotation(Class bean, E element) {
try {
return compute(bean, element, Function.identity(), Function.identity());
} catch (IllegalArgumentException ex) {
return null;
}
}
/**
* Reads the effective {@link Annotation} for the provided {@link InjectionPoint}.
*
* @param point source {@link InjectionPoint} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return the effective annotation for the provided {@link InjectionPoint}, never {@code null}
* @throws IllegalArgumentException In case the provided {@link InjectionPoint} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public T annotation(InjectionPoint point) {
return compute(point, (annotation, name) -> annotation);
}
/**
* Checks if this {@link AnnotationReader}'s {@link #annotationType()} is present either at the provided
* {@link AnnotatedElement} or the provided bean {@link Class}.
*
* @param bean type of the bean that declared the provided element
* @param element a {@link AnnotatedElement} possibly annotated with this {@link AnnotationReader}'s
* {@link #annotationType()}
* @return true, if provided element or bean are annotated with this {@link AnnotationReader}'s
* {@link #annotationType()}, else false.
*/
public boolean isPresent(Class bean, E element) {
return nameType == GAUGE.nameType
? element instanceof Method && element.isAnnotationPresent(annotationType)
: annotation(bean, element) != null;
}
/**
* Returns the metric name as defined by the provided {@link Annotation}
*
* @param annotation source annotation to read, not {@code null}
* @return name value of the provided source annotation
*/
public String name(T annotation) {
return name.apply(annotation);
}
/**
* Returns the metric name as defined by the MP specification for the annotation situation at hand for the provided
* {@link InjectionPoint}. This does take into account that annotations might have been added or removed at runtime.
*
* @param point source {@link InjectionPoint} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return full metric name as required by the MP specification
* @throws IllegalArgumentException In case the provided {@link InjectionPoint} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public String name(InjectionPoint point) {
return compute(point, this::name);
}
/**
* Returns the metric name as defined by the MP specification for the annotation situation at hand for the provided
* {@link AnnotatedMember}. This does take into account that annotations might have been added or removed at runtime.
*
* @param member source {@link AnnotatedMember} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return full metric name as required by the MP specification
* @throws IllegalArgumentException In case the provided {@link AnnotatedMember} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public String name(AnnotatedMember member) {
return compute(member, this::name);
}
/**
* Reads the effective name for the provided bean {@link Class} and {@link AnnotatedElement}. Either bean or element
* must have this {@link AnnotationReader}'s {@link Annotation}.
*
* @param bean type of the bean that declared the provided element possibly annotated with this
* {@link AnnotationReader}'s {@link #annotationType()}
* @param element a {@link AnnotatedElement} possibly annotated with this {@link AnnotationReader}'s
* {@link #annotationType()}
* @return full metric name as required by the MP specification
* @throws IllegalArgumentException In case neither the {@link AnnotatedElement} or the {@link Class} isn't
* annotated with this {@link AnnotationReader}'s {@link Annotation}.
*/
public String name(Class bean, E element) {
return compute(bean, element, this::name);
}
private String name(@SuppressWarnings("unused") T annotation, String name) {
return name; // used as method-ref-lambda
}
/**
* Returns the metric tags as defined by the provided {@link Annotation}
*
* @param annotation source annotation to read, not {@code null}
* @return tags value of the provided source annotation
*/
public Tag[] tags(T annotation) {
return tagsFromString(tags.apply(annotation));
}
/**
* Returns the {@link MetricID} as defined by the provided {@link Annotation}'s name and tags attributes.
*
* @param annotation source annotation to read, not {@code null}
* @return {@link MetricID} value of the provided source annotation
*/
public MetricID metricID(T annotation) {
return new MetricID(name(annotation), tags(annotation));
}
/**
* Returns the metric {@link MetricID} as defined by the MP specification for the annotation situation at hand for
* the provided {@link InjectionPoint}. This does take into account that annotations might have been added or
* removed at runtime.
*
* @param point source {@link InjectionPoint} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return {@link MetricID} with full metric name as required by the MP specification
* @throws IllegalArgumentException In case the provided {@link InjectionPoint} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public MetricID metricID(InjectionPoint point) {
return compute(point, this::metricID);
}
/**
* Returns the metric {@link MetricID} as defined by the MP specification for the annotation situation at hand for
* the provided {@link InjectionPoint}. This does take into account that annotations might have been added or
* removed at runtime.
*
* @param point source {@link AnnotatedMember} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return {@link MetricID} with full metric name as required by the MP specification
* @throws IllegalArgumentException In case the provided {@link AnnotatedMember} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public MetricID metricID(AnnotatedMember member) {
return compute(member, this::metricID);
}
/**
* Reads the effective {@link MetricID} for the provided bean {@link Class} and {@link AnnotatedElement}. Either
* bean or element must have this {@link AnnotationReader}'s {@link Annotation}.
*
* @param bean type of the bean that declared the provided element possibly annotated with this
* {@link AnnotationReader}'s {@link #annotationType()}
* @param element a {@link AnnotatedElement} possibly annotated with this {@link AnnotationReader}'s
* {@link #annotationType()}
* @return {@link MetricID} with full metric name as required by the MP specification
* @throws IllegalArgumentException In case neither the {@link AnnotatedElement} or the {@link Class} isn't
* annotated with this {@link AnnotationReader}'s {@link Annotation}.
*/
public MetricID metricID(Class bean, E element) {
return compute(bean, element, this::metricID);
}
private MetricID metricID(T annotation, String name) {
return new MetricID(name, tags(annotation));
}
/**
* Returns the metric description as defined by the provided {@link Annotation}
*
* @param annotation source annotation to read, not {@code null}
* @return description of the provided source annotation
*/
public String description(T annotation) {
return description.apply(annotation);
}
/**
* Returns the metric unit as defined by the provided {@link Annotation}
*
* @param annotation source annotation to read, not {@code null}
* @return unit of the provided source annotation
*/
public String unit(T annotation) {
return unit.apply(annotation);
}
/**
* Returns the scope as defined by the provided {@Link Annotation}
* @param annotation source annotation to read, not {@code null}
* @return scope of the provided source annotation
*/
public String scope(T annotation){
return scope.apply(annotation);
}
/**
* Returns the metric absolute flag as defined by the provided {@link Annotation}
*
* @param annotation source annotation to read, not {@code null}
* @return absolute flag of the provided source annotation
*/
public boolean absolute(T annotation) {
return absolute.test(annotation);
}
/**
* Returns the full {@link Metadata} as defined by the provided {@link Annotation}
*
* @param annotation source annotation to read, not {@code null}
* @return {@link Metadata} of the provided source annotation
*/
public Metadata metadata(T annotation) {
return metadata(annotation, name(annotation));
}
/**
* Returns the metric {@link Metadata} as defined by the MP specification for the annotation situation at hand for
* the provided {@link InjectionPoint}. This does take into account that annotations might have been added or
* removed at runtime.
*
* @param point source {@link InjectionPoint} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return {@link Metadata} with full metric name as required by the MP specification
* @throws IllegalArgumentException In case the provided {@link InjectionPoint} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public Metadata metadata(InjectionPoint point) {
AnnotationReader reader = asAutoType(point.getType());
return reader.compute(point, reader::metadata);
}
/**
* Returns the metric {@link Metadata} as defined by the MP specification for the annotation situation at hand for
* the provided {@link InjectionPoint}. This does take into account that annotations might have been added or
* removed at runtime.
*
* @param point source {@link AnnotatedMember} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @return {@link Metadata} with full metric name as required by the MP specification
* @throws IllegalArgumentException In case the provided {@link AnnotatedMember} isn't effectively annotated with
* this {@link AnnotationReader}'s {@link Annotation}.
*/
public Metadata metadata(AnnotatedMember member) {
AnnotationReader reader = asAutoType(member.getBaseType());
return reader.compute(member, reader::metadata);
}
/**
* Reads the effective {@link Metadata} for the provided bean {@link Class} and {@link AnnotatedElement}. Either
* bean or element must have this {@link AnnotationReader}'s {@link Annotation}.
*
* @param bean type of the bean that declared the provided element possibly annotated with this
* {@link AnnotationReader}'s {@link #annotationType()}
* @param element a {@link AnnotatedElement} possibly annotated with this {@link AnnotationReader}'s
* {@link #annotationType()}
* @return {@link Metadata} with full metric name as required by the MP specification
* @throws IllegalArgumentException In case neither the {@link AnnotatedElement} or the {@link Class} isn't
* annotated with this {@link AnnotationReader}'s {@link Annotation}.
*/
public Metadata metadata(Class bean, E element) {
AnnotationReader reader = this;
if (element instanceof Method) {
reader = asAutoType(((Method) element).getGenericReturnType());
} else if (element instanceof Field) {
reader = asAutoType(((Field) element).getGenericType());
}
return reader.compute(bean, element, reader::metadata);
}
private Metadata metadata(T annotation, String name) {
return Metadata.builder()
.withName(name)
.withDescription(description(annotation))
.withUnit(unit(annotation))
.build();
}
@Override
public boolean equals(Object obj) {
return obj instanceof AnnotationReader && annotationType == ((AnnotationReader) obj).annotationType;
}
@Override
public int hashCode() {
return annotationType.hashCode();
}
@Override
public String toString() {
return annotationType.toString();
}
/**
* Checks if an {@link Annotation} does not provide any information beyond the required name and tags.
*
* @param annotation source annotation to read, not {@code null}
* @return true, of no property is set to a value that would require using {@link Metadata} when registering, else
* false.
*/
public boolean isReference(T annotation) {
return unit(annotation).equals(MetricUnits.NONE)
&& description(annotation).isEmpty();
}
/**
* Resolves the {@link org.eclipse.microprofile.metrics.Metric} referred to by the provided {@link InjectionPoint}.
* If it does not exist, the metric is created. Lookup and creation are one atomic operation. Depending on the
* provided information in the effective {@link Annotation} for the provided {@link InjectionPoint} the metric is
* resolved or registered using {@link Metadata}, name and {@link Tag}s or just its name.
*
* A {@link org.eclipse.microprofile.metrics.Gauge} can only be resolved, not created.
*
* @param point source {@link InjectionPoint} for an annotated element having this {@link AnnotationReader}'s
* {@link #annotationType()}, not {@code null}
* @param metric type of the {@link org.eclipse.microprofile.metrics.Metric} to find or create, not {@code null}
* @param registry {@link MetricRegistry} to use, not {@code null}
* @return the resolved or registered metric, or {@code null} if a {@link org.eclipse.microprofile.metrics.Gauge}
* did not exist
*/
public M getOrRegister(InjectionPoint point, Class metric, MetricRegistry registry) {
T annotation = null;
try {
annotation = annotation(point);
} catch (IllegalArgumentException ex) {
// there was no annotation
String name = MetricRegistry.name(point.getMember().getDeclaringClass().getCanonicalName(), localName(point.getMember()));
return MetricUtils.getOrRegisterByName(registry, metric, name);
}
if (isReference(annotation)) {
return MetricUtils.getOrRegisterByNameAndTags(registry, metric, name(point), tags(annotation));
}
return MetricUtils.getOrRegisterByMetadataAndTags(registry, metric, metadata(point), tags(annotation));
}
private R compute(InjectionPoint point, BiFunction func) {
Annotated annotated = point.getAnnotated();
if (annotated instanceof AnnotatedMember) {
return compute((AnnotatedMember) annotated, func);
}
if (annotated instanceof AnnotatedParameter) {
return compute(point, (AnnotatedParameter) annotated, func);
}
throw new IllegalArgumentException("Unable to retrieve data for injection point [" + point
+ "], only members and parameters are supported");
}
private R compute(InjectionPoint point, AnnotatedParameter parameter, BiFunction func) {
//NB: This is a workaround as arquillians InjectionPoint implementation for parameters does return null for getJavaParameter
Executable annotated = (Executable) point.getMember();
Member member = new MemberParameter(annotated.getParameters()[parameter.getPosition()]);
return compute(member.getDeclaringClass(), member, parameter::getAnnotation, func);
}
private R compute(AnnotatedMember member, BiFunction func) {
Member jmember = ((AnnotatedMember) member).getJavaMember();
return compute(jmember.getDeclaringClass(), jmember, member::getAnnotation, func);
}
private R compute(Class bean, E element, BiFunction func) {
return compute(bean, element, element::getAnnotation, func);
}
private R compute(Class bean, Member member, Function, T> element, BiFunction func) {
return compute(bean, member, element,
annotation -> func.apply(annotation, namedOnElementLevel(annotation, member)),
annotation -> func.apply(annotation, namedOnClassLevel(annotation, bean, member)));
}
private R compute(Class bean, E element, Function onElement,
Function onClass) {
return compute(bean, element, element::getAnnotation, onElement, onClass);
}
private R compute(Class bean, Member member, Function, T> element, Function onElement,
Function onClass) {
T annotation = element.apply(annotationType);
if (annotation != null) {
return onElement.apply(annotation);
}
if (bean.isAnnotationPresent(annotationType)) {
return onClass.apply(bean.getAnnotation(annotationType));
}
for (Annotation a : bean.getAnnotations()) {
if (a.annotationType().isAnnotationPresent(Stereotype.class) && a.annotationType().isAnnotationPresent(annotationType)) {
return onClass.apply(a.annotationType().getAnnotation(annotationType));
}
}
if (bean.getSuperclass() != null) {
return compute(bean.getSuperclass(), member, element, onElement, onClass);
}
throw illegal(bean, member);
}
private String namedOnElementLevel(T annotation, Member member) {
String localName = name(annotation);
if (localName.isEmpty()) {
localName = localName(member);
}
return absolute(annotation)
? localName
: MetricRegistry.name(member.getDeclaringClass().getCanonicalName(), localName);
}
private String namedOnClassLevel(T annotation, Class bean, Member member) {
String context = name(annotation);
if (context.isEmpty()) {
context = absolute(annotation) ? bean.getSimpleName() : bean.getCanonicalName();
} else if (!absolute(annotation)) {
context = MetricRegistry.name(bean.getPackage().getName(), context);
}
return MetricRegistry.name(context, localName(member));
}
private static String localName(Member member) {
return member instanceof Constructor ? member.getDeclaringClass().getSimpleName() : member.getName();
}
private IllegalArgumentException illegal(Class bean, Member member) {
return new IllegalArgumentException("Neither given member " + member + "nor the given bean " + bean
+ " are annotated with " + annotationType);
}
/**
* A simple wrapper that lets us pass a {@link Parameter} as if it is a {@link Member}
* so that rest of the code can use {@link Member} as common abstraction.
*/
private static final class MemberParameter implements Member {
private final Parameter param;
MemberParameter(Parameter param) {
this.param = param;
}
@Override
public Class getDeclaringClass() {
return param.getDeclaringExecutable().getDeclaringClass();
}
@Override
public String getName() {
return param.getName();
}
@Override
public int getModifiers() {
return param.getModifiers();
}
@Override
public boolean isSynthetic() {
return param.isSynthetic();
}
@Override
public String toString() {
return param.toString();
}
}
public static Tag[] tagsFromString(String[] tags) {
if (tags == null || tags.length == 0) {
return new Tag[0];
}
return asList(tags).stream().map(AnnotationReader::tagFromString).toArray(Tag[]::new);
}
private static Tag tagFromString(String tag) {
int splitIndex = tag.indexOf('=');
if (splitIndex == -1) {
throw new IllegalArgumentException("invalid tag: " + tag + ", tags must be in the form key=value");
}
return new Tag(tag.substring(0, splitIndex), tag.substring(splitIndex + 1));
}
}