Module jdk.jfr
Package jdk.jfr

Class EventType


  • public final class EventType
extends Object
    Describes an event, its fields, settings and annotations.
    Since:
    9

    • Method Detail

      • getFields

        public List<ValueDescriptor> getFields​()
        Returns an immutable list of descriptors describing the event fields of this event type.
        Returns:
        the list of field descriptors, not null

      • getField

        public ValueDescriptor getField​(String name)
        Returns the field with the specified name, or null if it doesn't exist.
        Returns:
        a value descriptor describing the field, or null if the field with given name doesn't exist

      • getName

        public String getName​()
        Returns an identifier for the event, for example "jdk.jfr.CPULoad".

        The name is the fully qualified name of the event class, if not set using the Name annotation.

        Returns:
        the name, not null
        See Also:
        Name

      • getLabel

        public String getLabel​()
        Returns a human-readable name, for example "CPU Load".

        The label of an event class can be set with Label.

        Returns:
        the label, or null if a label has not been set
        See Also:
        Label

      • getId

        public long getId​()
        Returns a unique id for the event in the JVM.
        Returns:
        the id

      • getAnnotationElements

        public List<AnnotationElement> getAnnotationElements​()
        Returns an immutable list of annotation elements for this event type.
        Returns:
        an immutable list of annotation or an empty list if no annotations exists, not null

      • isEnabled

        public boolean isEnabled​()
        Returns true if event is enabled and at least one recording is running, false otherwise.

        By default events are enabled, but behavior can be changed by annotating event with @Enabled(false). Enablement can always be overridden by setting the "enabled" setting to "true" or "false", programmatically or by using a configuration file.

        Returns:
        true if event is enabled, false otherwise
        See Also:
        Enabled, Recording.enable(Class)

      • getDescription

        public String getDescription​()
        Returns a short sentence that describes the event class.

        The description of an event class can be set with Description.

        Returns:
        the description, or null if no description exists
        See Also:
        Description

      • getAnnotation

        public <A extends Annotation> A getAnnotation​(Class<A> annotationClass)
        Returns the first annotation for the specified type if an annotation element with the same name is directly present, else null.
        Type Parameters:
        A - the type of the annotation to query for and return if present
        Parameters:
        annotationClass - the Class object corresponding to the annotation type, not null
        Returns:
        this element's annotation for the specified annotation type if directly present, else null

      • getEventType

        public static EventType getEventType​(Class<? extends Event> eventClass)
        Returns the event type for an event class, or null if not present.
        Parameters:
        eventClass - the event class, not null
        Returns:
        the event class, or null if class is not available
        Throws:
        IllegalArgumentException - if eventClass is an abstract class
        IllegalStateException - if the class was annotated with Registered(false), but never registered manually

      • getSettingDescriptors

        public List<SettingDescriptor> getSettingDescriptors​()
        Returns an immutable list of setting descriptors that describes available event settings for this EventType.
        Returns:
        the list of setting descriptors for this event type, not null

      • getCategoryNames

        public List<String> getCategoryNames​()
        Returns the list of human-readable names that makes up the category for this event type, for instance "Java Application", "Statistics".
        Returns:
        an immutable list of category names, or a list with the name "Uncategorized" if no category has been set
        See Also:
        Category