Class EventType
- java.lang.Object
-
- jdk.jfr.EventType
public final class EventType extends Object
Describes an event, its fields, settings and annotations.
- Since:
- 9
Methods
Modifier and Type | Method | Description |
---|---|---|
<A extends Annotation> | getAnnotation(Class<A> annotationClass) | Returns the first annotation for the specified type if an annotation element with the same name is directly present, otherwise |
List<AnnotationElement> | getAnnotationElements() | Returns an immutable list of annotation elements for this event type. |
List<String> | getCategoryNames() | Returns the list of human-readable names that makes up the categories for this event type (for example, |
String | getDescription() | Returns a short sentence that describes the event class. |
static EventType | getEventType(Class<? extends Event> eventClass) | Returns the event type for an event class, or |
ValueDescriptor | getField(String name) | Returns the field with the specified name, or |
List<ValueDescriptor> | getFields() | Returns an immutable list of descriptors that describe the event fields of this event type. |
long | getId() | Returns a unique ID for this event type in the Java Virtual Machine (JVM). |
String | getLabel() | Returns a human-readable name (for example, |
String | getName() | Returns an identifier for the event (for example, |
List<SettingDescriptor> | getSettingDescriptors() | Returns an immutable list of the setting descriptors that describe the available event settings for this event type. |
boolean | isEnabled() | Returns |
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods
getFields
public List<ValueDescriptor> getFields()
Returns an immutable list of descriptors that describe 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 that describes the field, or
null
if the field with the specified name doesn't exist
getName
public String getName()
Returns an identifier for the event (for example, "jdk.CPULoad"
).
The identifier 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 is not set - See Also:
Label
getId
public long getId()
Returns a unique ID for this event type in the Java Virtual Machine (JVM).
- Returns:
- the ID that is used in the JVM
getAnnotationElements
public List<AnnotationElement> getAnnotationElements()
Returns an immutable list of annotation elements for this event type.
- Returns:
- an immutable list of annotations or an empty list if no annotations exists, not
null
isEnabled
public boolean isEnabled()
Returns true
if the event is enabled and at least one recording is running, false
otherwise.
By default, the event is enabled. The event can be enabled or disabled by setting the enabled setting to true
or false
, programmatically or by using a configuration file. The event can also be disabled by annotating event with the @Enabled(false)
annotation.
- 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, otherwise null
.
- Type Parameters:
-
A
- the type of the annotation to query for and return if present - Parameters:
-
annotationClass
- theClass
object that corresponds to the annotation type, notnull
- 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 it doesn't exist.
- Parameters:
-
eventClass
- the event class, notnull
- Returns:
- the event class, or null if class doesn't exist
- Throws:
-
IllegalArgumentException
- ifeventClass
is an abstract class -
IllegalStateException
- if the class is annotated withRegistered(false)
, but not manually registered
getSettingDescriptors
public List<SettingDescriptor> getSettingDescriptors()
Returns an immutable list of the setting descriptors that describe the available event settings for this event type.
- 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 categories for this event type (for example, "Java Application"
, "Statistics"
).
- Returns:
- an immutable list of category names, or a list with the name
"Uncategorized"
if no category is set - See Also:
Category
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/11/docs/api/jdk.jfr/jdk/jfr/EventType.html