OpenJDK 27 · jdk.jfr.AnnotationElement · APIdia, the JavaDoc alternative

Describes event metadata, such as labels, descriptions and units.

The following example shows how AnnotationElement can be used to dynamically define events.

List<AnnotationElement> typeAnnotations = new ArrayList<>();
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<AnnotationElement> fieldAnnotations = new ArrayList<>();
fieldAnnotations.add(new AnnotationElement(Label.class, "Message"));

List<ValueDescriptor> fields = new ArrayList<>();
fields.add(new ValueDescriptor(String.class, "message", fieldAnnotations));

EventFactory f = EventFactory.create(typeAnnotations, fields);
Event event = f.newEvent();
event.commit();

Modifier and Type	Field and Description
private final List<Object>	annotationValues
private final boolean	inBootClassLoader
private final Type	type

Constructor Summary

Access	Constructor and Description
pack-priv	AnnotationElement(Type type, List<Object> objects, boolean boot)
public	AnnotationElement(Class<? extends Annotation> interface extending `java.lang.annotation.Annotation`, not `null` annotationType, Map<String, Object> a `Map` with keys that match method names of the specified annotation interface values) Creates an annotation element to use for dynamically defined events.
public	AnnotationElement(Class<? extends Annotation> interface extending `java.lang.annotation.Annotation,` not `null` annotationType, Object the value that matches the `value` method of the specified `annotationType` value) Creates an annotation element to use for dynamically defined events.
public	AnnotationElement(Class<? extends Annotation> interface extending java.lang.annotation.Annotation, not `null` annotationType) Creates an annotation element to use for dynamically defined events.

Method Summary

Modifier and Type	Method and Description
private static void	checkType(Class<?> type)
public final < the type of the annotation to query for and return if it exists A> A	Returns: this element's annotation for the specified annotation type if it exists, else `null` getAnnotation(Class<? extends Annotation> the `Class object` corresponding to the annotation type, not `null` annotationType) Returns the first annotation for the specified type if an `AnnotationElement` with the same name exists, else `null`.
public List<AnnotationElement>	Returns: a list of meta annotation, not `null` getAnnotationElements() Returns an immutable list of annotation elements for this `AnnotationElement`.
pack-priv Type	getType()
public long	Returns: the type ID, not negative getTypeId() Returns the type ID for this `AnnotationElement`.
public String	Returns: type name, not `null` getTypeName() Returns the fully qualified name of the annotation type that corresponds to this `AnnotationElement` (for example, `"jdk.jfr.Label"`).
public Object	Returns: the annotation value, not `null`. getValue(String the name of the method in the annotation interface, not `null`. name) Returns a value for this `AnnotationElement`.
public List<ValueDescriptor>	Returns: the list of value descriptors for this `Annotation`, not `null` getValueDescriptors() Returns an immutable list of descriptors that describes the annotation values for this `AnnotationElement`.
public List<Object>	Returns: list of values, not `null` getValues() Returns an immutable list of annotation values in an order that matches the value descriptors for this `AnnotationElement`.
public boolean	Returns: `true` if method exists, `false` otherwise hasValue(String name of the method in the annotation interface to find, not `null` name) Returns `true` if an annotation value with the specified name exists in this `AnnotationElement`.
pack-priv boolean	isInBoot()
private static boolean	isKnownJFRAnnotation(Class<? extends Annotation> annotationType)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

annotationValues	back to summary
private final List<Object> annotationValues

inBootClassLoader	back to summary
private final boolean inBootClassLoader

type	back to summary
private final Type type

Constructor Detail

AnnotationElement	back to summary
pack-priv AnnotationElement(Type type, List<Object> objects, boolean boot)

AnnotationElement back to summary

AnnotationElement	back to summary
public AnnotationElement(Class<? extends Annotation> annotationType, Map<String, Object> values) Creates an annotation element to use for dynamically defined events. Supported value types are `byte`, `int`, `short`, `long`, `double`, `float`, `boolean`, `char`, and `String`. Enums, arrays and classes, are not supported. If `annotationType` has annotations (directly present, indirectly present, or associated), then those annotation are recursively included. However, both the `annotationType` and any annotation found recursively must have the `MetadataDefinition` annotation. To statically define events, see `Event` class. Parameters annotationType:Class<? extends Annotation> interface extending `java.lang.annotation.Annotation`, not `null` values:Map<String, Object> a `Map` with keys that match method names of the specified annotation interface Exceptions IllegalArgumentException: if value/key is `null`, an unsupported value type is used, or a value/key is used that doesn't match the signatures in the `annotationType`

public AnnotationElement(Class<? extends Annotation> annotationType, Map<String, Object> values)

Creates an annotation element to use for dynamically defined events.

Supported value types are byte, int, short, long, double, float, boolean, char, and String. Enums, arrays and classes, are not supported.

If annotationType has annotations (directly present, indirectly present, or associated), then those annotation are recursively included. However, both the annotationType and any annotation found recursively must have the MetadataDefinition annotation.

To statically define events, see Event class.

Parameters

annotationType:Class<? extends Annotation>: interface extending java.lang.annotation.Annotation, not null
values:Map<String, Object>: a Map with keys that match method names of the specified annotation interface

Exceptions

IllegalArgumentException:: if value/key is null, an unsupported value type is used, or a value/key is used that doesn't match the signatures in the annotationType

AnnotationElement back to summary

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

public AnnotationElement(Class<? extends Annotation> annotationType, Object value)

Creates an annotation element to use for dynamically defined events.

Supported value types are byte, int, short, long, double, float, boolean, char, and String. Enums, arrays, and classes are not supported.

If annotationType has annotations (directly present, indirectly present, or associated), then those annotations are recursively included. However, both annotationType and any annotation found recursively must have the MetadataDefinition annotation.

To statically define events, see Event class.

Parameters

annotationType:Class<? extends Annotation>: interface extending java.lang.annotation.Annotation, not null
value:Object: the value that matches the value method of the specified annotationType

Exceptions

IllegalArgumentException:: if value/key is null, an unsupported value type is used, or a value/key is used that doesn't match the signatures in the annotationType

AnnotationElement back to summary

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

public AnnotationElement(Class<? extends Annotation> annotationType)

Creates an annotation element to use for dynamically defined events.

Supported value types are byte, short, int, long, double, float, boolean, char, and String. Enums, arrays, and classes are not supported.

If annotationType has annotations (directly present, indirectly present or associated), then those annotation are recursively included. However, both annotationType and any annotation found recursively must have the MetadataDefinition annotation.

To statically define events, see Event class.

Parameters

annotationType:Class<? extends Annotation>: interface extending java.lang.annotation.Annotation, not null

Method Detail

checkType	back to summary
private static void checkType(Class<?> type)

getAnnotation back to summary

getAnnotation	back to summary
public final <A> A getAnnotation(Class<? extends Annotation> annotationType) Returns the first annotation for the specified type if an `AnnotationElement` with the same name exists, else `null`. Parameters <A> the type of the annotation to query for and return if it exists annotationType:Class<? extends Annotation> the `Class object` corresponding to the annotation type, not `null` Returns:A this element's annotation for the specified annotation type if it exists, else `null`

public final <A> A getAnnotation(Class<? extends Annotation> annotationType)

Returns the first annotation for the specified type if an AnnotationElement with the same name exists, else null.

Parameters

<A>: the type of the annotation to query for and return if it exists
annotationType:Class<? extends Annotation>: the Class object corresponding to the annotation type, not null

Returns:A

this element's annotation for the specified annotation type if it exists, else null

getAnnotationElements back to summary

getAnnotationElements	back to summary
public List<AnnotationElement> getAnnotationElements() Returns an immutable list of annotation elements for this `AnnotationElement`. Returns:List<AnnotationElement> a list of meta annotation, not `null`

public List<AnnotationElement> getAnnotationElements()

Returns an immutable list of annotation elements for this AnnotationElement.

Returns:List<AnnotationElement>: a list of meta annotation, not null

getType	back to summary
pack-priv Type getType()

getTypeId back to summary

getTypeId	back to summary
public long getTypeId() Returns the type ID for this `AnnotationElement`. 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. Returns:long the type ID, not negative

public long getTypeId()

Returns the type ID for this AnnotationElement.

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.

Returns:long: the type ID, not negative

getTypeName back to summary

getTypeName	back to summary
public String getTypeName() Returns the fully qualified name of the annotation type that corresponds to this `AnnotationElement` (for example, `"jdk.jfr.Label"`). Returns:String type name, not `null`

public String getTypeName()

Returns the fully qualified name of the annotation type that corresponds to this AnnotationElement (for example, "jdk.jfr.Label").

Returns:String: type name, not null

getValue back to summary

getValue	back to summary
public Object getValue(String name) Returns a value for this `AnnotationElement`. Parameters name:String the name of the method in the annotation interface, not `null`. Returns:Object the annotation value, not `null`. Exceptions IllegalArgumentException: if a method with the specified name does not exist in the annotation

public Object getValue(String name)

Returns a value for this AnnotationElement.

Parameters

name:String: the name of the method in the annotation interface, not null.

Returns:Object

the annotation value, not null.

Exceptions

IllegalArgumentException:: if a method with the specified name does not exist in the annotation

getValueDescriptors back to summary

getValueDescriptors	back to summary
public List<ValueDescriptor> getValueDescriptors() Returns an immutable list of descriptors that describes the annotation values for this `AnnotationElement`. Returns:List<ValueDescriptor> the list of value descriptors for this `Annotation`, not `null`

public List<ValueDescriptor> getValueDescriptors()

Returns an immutable list of descriptors that describes the annotation values for this AnnotationElement.

Returns:List<ValueDescriptor>: the list of value descriptors for this Annotation, not null

getValues back to summary

getValues	back to summary
public List<Object> getValues() Returns an immutable list of annotation values in an order that matches the value descriptors for this `AnnotationElement`. Returns:List<Object> list of values, not `null`

public List<Object> getValues()

Returns an immutable list of annotation values in an order that matches the value descriptors for this AnnotationElement.

Returns:List<Object>: list of values, not null

hasValue back to summary

hasValue	back to summary
public boolean hasValue(String name) Returns `true` if an annotation value with the specified name exists in this `AnnotationElement`. Parameters name:String name of the method in the annotation interface to find, not `null` Returns:boolean `true` if method exists, `false` otherwise

public boolean hasValue(String name)

Returns true if an annotation value with the specified name exists in this AnnotationElement.

Parameters

name:String: name of the method in the annotation interface to find, not null

Returns:boolean

true if method exists, false otherwise

isInBoot	back to summary
pack-priv boolean isInBoot()

isKnownJFRAnnotation	back to summary
private static boolean isKnownJFRAnnotation(Class<? extends Annotation> annotationType)

public final Class AnnotationElement

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail