org.apache.hadoop.service

Class ServiceOperations

java.lang.Object

org.apache.hadoop.service.ServiceOperations

@InterfaceAudience.Public
@InterfaceStability.Evolving
public final class ServiceOperations
extends Object

This class contains a set of methods to work with services, especially to walk them through their lifecycle.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ServiceOperations.ServiceListeners Class to manage a list of ServiceStateChangeListener instances, including a notification loop that is robust against changes to the list during the notification process.

Method Summary

Methods

Modifier and Type	Method and Description
static void	stop(Service service) Stop a service.
static Exception	stopQuietly(org.slf4j.Logger log, Service service) Stop a service; if it is null do nothing.
static Exception	stopQuietly(org.apache.commons.logging.Log log, Service service) Stop a service; if it is null do nothing.
static Exception	stopQuietly(Service service) Stop a service; if it is null do nothing.

Methods inherited from class java.lang.Object

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

Method Detail

stop

public static void stop(Service service)

Stop a service.

Do nothing if the service is null or not in a state in which it can be/needs to be stopped.

The service state is checked before the operation begins. This process is not thread safe.

Parameters:

service - a service or null

stopQuietly

public static Exception stopQuietly(Service service)

Stop a service; if it is null do nothing. Exceptions are caught and logged at warn level. (but not Throwables). This operation is intended to be used in cleanup operations

Parameters:

service - a service; may be null

Returns:

any exception that was caught; null if none was.

stopQuietly

public static Exception stopQuietly(org.apache.commons.logging.Log log,
                    Service service)

Stop a service; if it is null do nothing. Exceptions are caught and logged at warn level. (but not Throwables). This operation is intended to be used in cleanup operations

Parameters:

log - the log to warn at

service - a service; may be null

Returns:

any exception that was caught; null if none was.

See Also:

stopQuietly(Service)

stopQuietly

public static Exception stopQuietly(org.slf4j.Logger log,
                    Service service)

Stop a service; if it is null do nothing. Exceptions are caught and logged at warn level. (but not Throwables). This operation is intended to be used in cleanup operations

Parameters:

log - the log to warn at

service - a service; may be null

Returns:

any exception that was caught; null if none was.

See Also:

stopQuietly(Service)