Class RecordingFile

java.lang.Object

jdk.jfr.consumer.RecordingFile

All Implemented Interfaces:: Closeable, AutoCloseable

public final class RecordingFile extends Object implements Closeable

A recording file.

The following example shows how to read and print all events in a recording file.

try (RecordingFile recordingFile = new RecordingFile(Paths.get("recording.jfr"))) {
    while (recordingFile.hasMoreEvents()) {
        RecordedEvent event = recordingFile.readEvent();
        System.out.println(event);
    }
}

Since:: 9

Constructor Summary

Constructor	Description
`RecordingFile(Path file)`	Creates a recording file.

Method Summary

Modifier and Type	Method	Description
`void`	`close()`	Closes this recording file and releases any system resources that are associated with it.
`boolean`	`hasMoreEvents()`	Returns `true` if unread events exist in the recording file, `false` otherwise.
`static List<RecordedEvent>`	`readAllEvents(Path path)`	Returns a list of all events in a file.
`RecordedEvent`	`readEvent()`	Reads the next event in the recording.
`List<EventType>`	`readEventTypes()`	Returns a list of all event types in this recording.
`void`	`write(Path destination, Predicate<RecordedEvent> filter)`	Filter out events and write them to a new file.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

RecordingFile

public RecordingFile(Path file) throws IOException

Creates a recording file.

Only recording files from trusted sources should be used.

Parameters:: file - the path of the file to open, not null
Throws:: IOException - if it's not a valid recording file, or an I/O error occurred; NoSuchFileException - if the file can't be located

Method Details

readEvent

public RecordedEvent readEvent() throws IOException

Reads the next event in the recording.

Returns:

the next event, not null

Throws:

EOFException - if no more events exist in the recording file

IOException - if an I/O error occurs

See Also:

hasMoreEvents

public boolean hasMoreEvents()

Returns true if unread events exist in the recording file, false otherwise.

Returns:: true if unread events exist in the recording, false otherwise.

readEventTypes

public List<EventType> readEventTypes() throws IOException

Returns a list of all event types in this recording.

Returns:

a list of event types, not null

Throws:

IOException - if an I/O error occurred while reading from the file

See Also:

close

public void close() throws IOException

Closes this recording file and releases any system resources that are associated with it.

Specified by:: close in interface AutoCloseable
Specified by:: close in interface Closeable
Throws:: IOException - if an I/O error occurred

write

public void write(Path destination, Predicate<RecordedEvent> filter) throws IOException

Filter out events and write them to a new file.

Parameters:: destination - path where the new file should be written, not null; filter - filter that determines if an event should be included, not null
Throws:: IOException - if an I/O error occurred, it's not a Flight Recorder file or a version of a JFR file that can't be parsed
Since:: 19

readAllEvents

public static List<RecordedEvent> readAllEvents(Path path) throws IOException

Returns a list of all events in a file.

This method is intended for simple cases where it's convenient to read all events in a single operation. It isn't intended for reading large files.

Only recording files from trusted sources should be used.

Parameters:: path - the path to the file, not null
Returns:: the events from the file as a List object; whether the List is modifiable or not is implementation dependent and therefore not specified, not null
Throws:: IOException - if an I/O error occurred, it's not a Flight Recorder file or a version of a JFR file that can't be parsed

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
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).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.