Package Summary Overview Summary

### class:RecordingStream [NONE]
All Implemented Interfaces: `AutoCloseable`, `EventStream` public final class RecordingStream extends Object implements AutoCloseable, EventStream A recording stream produces events from the current JVM (Java Virtual Machine). The following example shows how to record events using the default configuration and print the Garbage Collection, CPU Load and JVM Information event to standard out.
    Configuration c = Configuration.getConfiguration("default");
    try (var rs = new RecordingStream(c)) {
        rs.onEvent("jdk.GarbageCollection", System.out::println);
        rs.onEvent("jdk.CPULoad", System.out::println);
        rs.onEvent("jdk.JVMInformation", System.out::println);
        rs.start();
    }
Since: 14

### constructor:RecordingStream() [NONE]
### RecordingStream public RecordingStream() Creates an event stream for the current JVM (Java Virtual Machine). Throws: `IllegalStateException` - if Flight Recorder can't be created (for example, if the Java Virtual Machine (JVM) lacks Flight Recorder support, or if the file repository can't be created or accessed) `SecurityException` - if a security manager exists and the caller does not have `FlightRecorderPermission("accessFlightRecorder")`

### constructor:RecordingStream(jdk.jfr.Configuration) [NONE]
### RecordingStream public RecordingStream (Configuration configuration) Creates a recording stream using settings from a configuration. The following example shows how to create a recording stream that uses a predefined configuration.
    var c = Configuration.getConfiguration("default");
    try (var rs = new RecordingStream(c)) {
        rs.onEvent(System.out::println);
        rs.start();
    }
Parameters: `configuration` - configuration that contains the settings to use, not `null` Throws: `IllegalStateException` - if Flight Recorder can't be created (for example, if the Java Virtual Machine (JVM) lacks Flight Recorder support, or if the file repository can't be created or accessed) `SecurityException` - if a security manager is used and FlightRecorderPermission "accessFlightRecorder" is not set. See Also: `Configuration`

### method:enable(java.lang.String) [NONE]
### enable public EventSettings enable (String name) Enables the event with the specified name. If multiple events have the same name (for example, the same class is loaded in different class loaders), then all events that match the name are enabled. To enable a specific class, use the `enable(Class)` method or a `String` representation of the event type ID. Parameters: `name` - the settings for the event, not `null` Returns: an event setting for further configuration, not `null` See Also: `EventType`

### method:setSettings(java.util.Map) [NONE]
### setSettings public void setSettings (Map<String, String> settings) Replaces all settings for this recording stream. The following example records 20 seconds using the "default" configuration and then changes settings to the "profile" configuration.
    Configuration defaultConfiguration = Configuration.getConfiguration("default");
    Configuration profileConfiguration = Configuration.getConfiguration("profile");
    try (var rs = new RecordingStream(defaultConfiguration)) {
        rs.onEvent(System.out::println);
        rs.startAsync();
        Thread.sleep(20_000);
        rs.setSettings(profileConfiguration.getSettings());
        Thread.sleep(20_000);
    }
Parameters: `settings` - the settings to set, not `null` See Also: `Recording.setSettings(Map)`

### method:enable(java.lang.Class) [NONE]
### enable public EventSettings enable (Class<? extends Event> eventClass) Enables event. Parameters: `eventClass` - the event to enable, not `null` Returns: an event setting for further configuration, not `null` Throws: `IllegalArgumentException` - if `eventClass` is an abstract class or not a subclass of `Event`

### method:disable(java.lang.String) [NONE]
### disable public EventSettings disable (String name) Disables event with the specified name. If multiple events with same name (for example, the same class is loaded in different class loaders), then all events that match the name are disabled. To disable a specific class, use the `disable(Class)` method or a `String` representation of the event type ID. Parameters: `name` - the settings for the event, not `null` Returns: an event setting for further configuration, not `null`

### method:disable(java.lang.Class) [NONE]
### disable public EventSettings disable (Class<? extends Event> eventClass) Disables event. Parameters: `eventClass` - the event to enable, not `null` Returns: an event setting for further configuration, not `null` Throws: `IllegalArgumentException` - if `eventClass` is an abstract class or not a subclass of `Event`

### method:setMaxAge(java.time.Duration) [NONE]
### setMaxAge public void setMaxAge (Duration maxAge) Determines how far back data is kept for the stream. To control the amount of recording data stored on disk, the maximum length of time to retain the data can be specified. Data stored on disk that is older than the specified length of time is removed by the Java Virtual Machine (JVM). If neither maximum limit or the maximum age is set, the size of the recording may grow indefinitely if events are on Parameters: `maxAge` - the length of time that data is kept, or `null` if infinite Throws: `IllegalArgumentException` - if `maxAge` is negative `IllegalStateException` - if the recording is in the `CLOSED` state

### method:setMaxSize(long) [NONE]
### setMaxSize public void setMaxSize (long maxSize) Determines how much data is kept for the stream. To control the amount of recording data that is stored on disk, the maximum amount of data to retain can be specified. When the maximum limit is exceeded, the Java Virtual Machine (JVM) removes the oldest chunk to make room for a more recent chunk. If neither maximum limit or the maximum age is set, the size of the recording may grow indefinitely. The size is measured in bytes. Parameters: `maxSize` - the amount of data to retain, `0` if infinite Throws: `IllegalArgumentException` - if `maxSize` is negative `IllegalStateException` - if the recording is in `CLOSED` state

### method:setReuse(boolean) [NONE]
### setReuse public void setReuse (boolean reuse) Description copied from interface: `EventStream` Specifies that the event object in an `EventStream.onEvent(Consumer)` action can be reused. If reuse is set to `true`, an action should not keep a reference to the event object after the action has completed. Specified by: `setReuse` in interface `EventStream` Parameters: `reuse` - `true` if an event object can be reused, `false` otherwise

### method:setOrdered(boolean) [NONE]
### setOrdered public void setOrdered (boolean ordered) Description copied from interface: `EventStream` Specifies that events arrives in chronological order, sorted by the time they were committed to the stream. Specified by: `setOrdered` in interface `EventStream` Parameters: `ordered` - if event objects arrive in chronological order to `EventStream.onEvent(Consumer)`

### method:setStartTime(java.time.Instant) [NONE]
### setStartTime public void setStartTime (Instant startTime) Description copied from interface: `EventStream` Specifies the start time of the stream. The start time must be set before starting the stream Specified by: `setStartTime` in interface `EventStream` Parameters: `startTime` - the start time, not `null` See Also: `EventStream.start()` `EventStream.startAsync()`

### method:setEndTime(java.time.Instant) [NONE]
### setEndTime public void setEndTime (Instant endTime) Description copied from interface: `EventStream` Specifies the end time of the stream. The end time must be set before starting the stream. At end time, the stream is closed. Specified by: `setEndTime` in interface `EventStream` Parameters: `endTime` - the end time, not `null` See Also: `EventStream.start()` `EventStream.startAsync()`

### method:onEvent(java.lang.String,java.util.function.Consumer) [NONE]
### onEvent public void onEvent (String eventName, Consumer<RecordedEvent> action) Description copied from interface: `EventStream` Registers an action to perform on all events matching a name. Specified by: `onEvent` in interface `EventStream` Parameters: `eventName` - the name of the event, not `null` `action` - an action to perform on each `RecordedEvent` matching the event name, not `null`

### method:onEvent(java.util.function.Consumer) [NONE]
### onEvent public void onEvent (Consumer<RecordedEvent> action) Description copied from interface: `EventStream` Registers an action to perform on all events in the stream. To perform an action on a subset of event types, consider using `EventStream.onEvent(String, Consumer)` and `EventStream.onMetadata(Consumer)` as it is likely more performant than any selection or filtering mechanism implemented in a generic action. Specified by: `onEvent` in interface `EventStream` Parameters: `action` - an action to perform on each `RecordedEvent`, not `null` See Also: `EventStream.onEvent(Consumer)` `EventStream.onMetadata(Consumer)`

### method:onFlush(java.lang.Runnable) [NONE]
### onFlush public void onFlush (Runnable action) Description copied from interface: `EventStream` Registers an action to perform after the stream has been flushed. Specified by: `onFlush` in interface `EventStream` Parameters: `action` - an action to perform after the stream has been flushed, not `null`

### method:onClose(java.lang.Runnable) [NONE]
### onClose public void onClose (Runnable action) Description copied from interface: `EventStream` Registers an action to perform when the stream is closed. If the stream is already closed, the action will be performed immediately in the current thread. Specified by: `onClose` in interface `EventStream` Parameters: `action` - an action to perform after the stream is closed, not `null` See Also: `EventStream.close()`

### method:onError(java.util.function.Consumer) [NONE]
### onError public void onError (Consumer<Throwable> action) Description copied from interface: `EventStream` Registers an action to perform if an exception occurs. If an action is not registered, an exception stack trace is printed to standard error. Registering an action overrides the default behavior. If multiple actions have been registered, they are performed in the order of registration. If this method itself throws an exception, resulting behavior is undefined. Specified by: `onError` in interface `EventStream` Parameters: `action` - an action to perform if an exception occurs, not `null`

### method:close() [NONE]
### close public void close() Description copied from interface: `AutoCloseable` Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by the `try`-with-resources statement. Specified by: `close` in interface `AutoCloseable` Specified by: `close` in interface `EventStream`

### method:remove(java.lang.Object) [NONE]
### remove public boolean remove (Object action) Description copied from interface: `EventStream` Unregisters an action. If the action has been registered multiple times, all instances are unregistered. Specified by: `remove` in interface `EventStream` Parameters: `action` - the action to unregister, not `null` Returns: `true` if the action was unregistered, `false` otherwise See Also: `EventStream.onEvent(Consumer)` `EventStream.onEvent(String, Consumer)` `EventStream.onFlush(Runnable)` `EventStream.onClose(Runnable)` `EventStream.onError(Consumer)`

### method:start() [NONE]
### start public void start() Description copied from interface: `EventStream` Starts processing of actions. Actions are performed in the current thread. To stop the stream, use the `EventStream.close()` method. Specified by: `start` in interface `EventStream`

### method:startAsync() [NONE]
### startAsync public void startAsync() Starts asynchronous processing of actions. Actions are performed in a single separate thread. To stop the stream, use the `close()` method. The following example prints the CPU usage for ten seconds. When the current thread leaves the try-with-resources block the stream is stopped/closed.
    try (var stream = new RecordingStream()) {
        stream.enable("jdk.CPULoad").withPeriod(Duration.ofSeconds(1));
        stream.onEvent("jdk.CPULoad", event -> {
            System.out.println(event);
        });
        stream.startAsync();
        Thread.sleep(10_000);
    }
Specified by: `startAsync` in interface `EventStream` Throws: `IllegalStateException` - if the stream is already started or closed

### method:stop() [NONE]
### stop public boolean stop() Stops the recording stream. Stops a started stream and waits until all events in the recording have been consumed. Invoking this method in an action, for example in the `onEvent(Consumer)` method, could block the stream indefinitely. To stop the stream abruptly, use the `close()` method. The following code snippet illustrates how this method can be used in conjunction with the `startAsync()` method to monitor what happens during a test method:
    AtomicBoolean socketUse = new AtomicBoolean();
    try (var r = new RecordingStream()) {
        r.setMaxSize(Long.MAX_VALUE);
        r.enable("jdk.SocketWrite").withoutThreshold();
        r.enable("jdk.SocketRead").withoutThreshold();
        r.onEvent(event -> socketUse.set(true));
        r.startAsync();
        testFoo();
        r.stop();
        if (socketUse.get()) {
            r.dump(Path.of("socket-events.jfr"));
            throw new AssertionError("testFoo() should not use network");
        }
    }
Returns: `true` if recording is stopped, `false` otherwise Throws: `IllegalStateException` - if the recording is not started or is already stopped Since: 20

### method:dump(java.nio.file.Path) [NONE]
### dump public void dump (Path destination) throws IOException Writes recording data to a file. The recording stream must be started, but not closed. It's highly recommended that a max age or max size is set before starting the stream. Otherwise, the dump may not contain any events. Parameters: `destination` - the location where recording data is written, not `null` Throws: `IOException` - if the recording data can't be copied to the specified location, or if the stream is closed, or not started. `SecurityException` - if a security manager exists and the caller doesn't have `FilePermission` to write to the destination path Since: 17 See Also: `setMaxAge(Duration)` `setMaxSize(long)`

### method:awaitTermination(java.time.Duration) [NONE]
### awaitTermination public void awaitTermination (Duration timeout) throws InterruptedException Description copied from interface: `EventStream` Blocks until all actions are completed, or the stream is closed, or the timeout occurs, or the current thread is interrupted, whichever happens first. Specified by: `awaitTermination` in interface `EventStream` Parameters: `timeout` - the maximum time to wait, not `null` Throws: `InterruptedException` - if interrupted while waiting See Also: `EventStream.start()` `EventStream.startAsync()` `Thread.interrupt()`

### method:awaitTermination() [NONE]
### awaitTermination public void awaitTermination() throws InterruptedException Description copied from interface: `EventStream` Blocks until all actions are completed, or the stream is closed, or the current thread is interrupted, whichever happens first. Specified by: `awaitTermination` in interface `EventStream` Throws: `InterruptedException` - if interrupted while waiting See Also: `EventStream.start()` `EventStream.startAsync()` `Thread.interrupt()`