Module jdk.jfr

Package jdk.jfr.consumer

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 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

Constructors

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 java.lang.Object

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

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

SecurityException - if a security manager exists and its checkRead method denies read access to the file.

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()

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:

• hasMoreEvents()

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

SecurityException - if a security manager exists and its checkWrite method denies write access to the file

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

SecurityException - if a security manager exists and its checkRead method denies read access to the file.