Class Configuration

java.lang.Object

jdk.jfr.Configuration

public final class Configuration
extends Object

A collection of settings and metadata describing the configuration.

The following example shows how the Configuration class can be used to list available configurations and how to pass a configuration object to a Recording.

public static void main(String... args) throws Exception {
    if (args.length == 0) {
        System.out.println("Configurations:");
        for (Configuration c : Configuration.getConfigurations()) {
            System.out.println("Name: " + c.getName());
            System.out.println("Label: " + c.getLabel());
            System.out.println("Description: " + c.getDescription());
            System.out.println("Provider: " + c.getProvider());
            System.out.println();
        }
    } else {
        String name = args[0];
        Configuration c = Configuration.getConfiguration(name);
        try (Recording r = new Recording(c)) {
            System.out.println("Starting recording with settings:");
            for (Map.Entry<String, String> setting : c.getSettings().entrySet()) {
                System.out.println(setting.getKey() + " = " + setting.getValue());
            }
            r.start();
        }
    }
}

Since:

9

Method Summary

Modifier and Type	Method	Description
static Configuration	create(Reader reader)	Reads a configuration from a character stream.
static Configuration	create(Path path)	Reads a configuration from a file.
static Configuration	getConfiguration(String name)	Returns a predefined configuration.
static List<Configuration>	getConfigurations()	Returns an immutable list of predefined configurations for this Java Virtual Machine (JVM).
String	getContents()	Returns a textual representation of the configuration (for example, the contents of a JFC file).
String	getDescription()	Returns a short sentence that describes the configuration (for example "Low overhead configuration safe for continuous use in production environments")
String	getLabel()	Returns a human-readable name (for example, "Continuous" or "Profiling"}.
String	getName()	Returns an identifying name (for example, "default" or "profile").
String	getProvider()	Returns who created the configuration (for example "OpenJDK").
Map<String,String>	getSettings()	Returns the settings that specify how a recording is configured.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Method Details

getSettings

public Map<String,String> getSettings()

Returns the settings that specify how a recording is configured.

Modifying the returned Map object doesn't change the configuration.

Returns:

settings, not null

getName

public String getName()

Returns an identifying name (for example, "default" or "profile").

Returns:

the name, or null if it doesn't exist

getLabel

public String getLabel()

Returns a human-readable name (for example, "Continuous" or "Profiling"}.

Returns:

the label, or null if it doesn't exist

getDescription

public String getDescription()

Returns a short sentence that describes the configuration (for example "Low overhead configuration safe for continuous use in production environments")

Returns:

the description, or null if it doesn't exist

getProvider

public String getProvider()

Returns who created the configuration (for example "OpenJDK").

Returns:

the provider, or null if it doesn't exist

getContents

public String getContents()

Returns a textual representation of the configuration (for example, the contents of a JFC file).

Returns:

contents, or null if it doesn't exist

See Also:

• getContents()

create

public static Configuration create(Path path)
                            throws IOException,
ParseException

Reads a configuration from a file.

Parameters:

path - the file that contains the configuration, not null

Returns:

the read Configuration, not null

Throws:

ParseException - if the file can't be parsed

IOException - if the file can't be read

See Also:

• File.getPath()

create

public static Configuration create(Reader reader)
                            throws IOException,
ParseException

Reads a configuration from a character stream.

Parameters:

reader - a Reader that provides the configuration contents, not null

Returns:

a configuration, not null

Throws:

IOException - if an I/O error occurs while trying to read contents from the Reader

ParseException - if the file can't be parsed

getConfiguration

public static Configuration getConfiguration(String name)
                                      throws IOException,
ParseException

Returns a predefined configuration.

See getConfigurations() for available configuration names.

Parameters:

name - the name of the configuration (for example, "default" or "profile")

Returns:

a configuration, not null

Throws:

IOException - if a configuration with the given name does not exist, or if an I/O error occurs while reading the configuration file

ParseException - if the configuration file can't be parsed

getConfigurations

public static List<Configuration> getConfigurations()

Returns an immutable list of predefined configurations for this Java Virtual Machine (JVM).

Returns:

the list of predefined configurations, not null