Class QSingleInstanceFileBasedManager

java.lang.Object

org.jpos.q2.QBeanSupport

org.jpos.q2.qbean.QSingleInstanceFileBasedManager

All Implemented Interfaces:

Configurable, QBean, QBeanSupportMBean, QPersist

public class QSingleInstanceFileBasedManager
extends QBeanSupport

QBean that enforces a single live Q2 instance by acquiring an exclusive file lock on a configured lockfile; a second instance fails to start when the file is already locked.

Field Summary

Fields inherited from class QBeanSupport

cfg, log, scheduledThreadPoolExecutor

Modifier and Type	Field	Description
protected Configuration	cfg	Configuration applied to this bean by the container.
protected Log	log	Logger associated with this bean.
protected ScheduledThreadPoolExecutor	scheduledThreadPoolExecutor	Lazily-allocated scheduler shared with subclasses; see QBeanSupport.getScheduledThreadPoolExecutor().

Fields inherited from interface QBean

DESTROYED, FAILED, STARTED, STARTING, stateString, STOPPED, STOPPING

Modifier and Type	Field	Description
static final int	DESTROYED	QBean has been destroyed.
static final int	FAILED	QBean has failed.
static final int	STARTED	QBean is running.
static final int	STARTING	QBean is in the process of starting.
static final String[]	stateString	Human-readable names for each QBean state, indexed by state constant.
static final int	STOPPED	QBean is stopped.
static final int	STOPPING	QBean is in the process of stopping.

Constructor Summary

Constructors

Constructor	Description
QSingleInstanceFileBasedManager()	Default constructor; no instance state to initialise.

Method Summary

Modifier and Type	Method	Description
protected void	initService()	Called during the init lifecycle phase; subclasses may override.
protected void	stopService()	Called during the stop lifecycle phase; subclasses may override.

Methods inherited from class QBeanSupport

addAttr, close, createElement, defaultRealm, destroy, destroyService, getAttrs, getAttrs, getConfiguration, getDump, getFactory, getLoader, getLoaderURLS, getLog, getLogger, getName, getPersist, getProperties, getProperty, getRealm, getScheduledThreadPoolExecutor, getServer, getState, getStateAsString, init, isModified, running, setAttr, setConfiguration, setLogger, setModified, setName, setPersist, setProperty, setRealm, setServer, setState, start, startService, stop

Modifier and Type	Method	Description
protected void	addAttr(org.jdom2.Element e, String name, Object obj, String type)	Appends an <attr> child element with name/type/value to e.
protected void	close(Closeable... closeables)	Closes a sequence of Closeable resources, logging any failures as a warning.
protected org.jdom2.Element	createElement(String name, Class mbeanClass)	Builds a JDOM Element reflecting the bean's persistent attributes, driven by the JavaBean introspection of mbeanClass.
protected String	defaultRealm()	Returns the default realm for this bean; subclasses may override.
void	destroy()	destroy the service
protected void	destroyService()	Called during the destroy lifecycle phase; subclasses may override.
protected Iterator	getAttrs()	Iterates over top-level <attr> children of the persisted element.
protected Iterator	getAttrs(String parent)	Iterates over <attr> children nested under the given parent element name.
Configuration	getConfiguration()	Returns the configuration applied to this bean.
String	getDump()	Returns a textual dump of this bean's state.
QFactory	getFactory()	Returns the QFactory associated with the hosting Q2 server.
QClassLoader	getLoader()	Returns the QClassLoader for this bean.
URL[]	getLoaderURLS()	Returns the URLs registered with the class loader.
Log	getLog()	Returns the Log used by this bean.
String	getLogger()	Returns the logger name.
String	getName()	Returns the bean name.
org.jdom2.Element	getPersist()	Returns the persistent configuration element for this QBean.
protected Iterator	getProperties(String parent)	Iterates over <property> children nested under the given parent element name.
protected String	getProperty(Iterator props, String name)	Returns the value of the named property from an iterator of <property> elements.
String	getRealm()	Returns the logging realm.
protected ScheduledThreadPoolExecutor	getScheduledThreadPoolExecutor()	Lazily creates and returns a ScheduledThreadPoolExecutor for use by subclasses.
Q2	getServer()	Returns the Q2 server instance.
int	getState()	Returns the current state of this QBean.
String	getStateAsString()	Returns the current state as a human-readable string.
void	init()	init the service
boolean	isModified()	Returns true if this QBean's configuration has been modified since last save.
boolean	running()	Indicates whether this bean is currently starting or running.
protected void	setAttr(Iterator attrs, String name, Object obj)	Updates the value of the named attribute within an iterator of <attr> elements.
void	setConfiguration(Configuration cfg)	Configures this object with the supplied Configuration.
void	setLogger(String loggerName)	Sets the logger by name.
void	setModified(boolean modified)	Marks this bean's persistent state as modified or in sync.
void	setName(String name)	Sets the bean name.
void	setPersist(org.jdom2.Element persist)	Sets the persistent configuration element.
protected void	setProperty(Iterator props, String name, String value)	Updates the value attribute of the named property within an iterator of <property> elements.
void	setRealm(String realm)	Sets the logging realm.
void	setServer(Q2 server)	Sets the Q2 server instance for this QBean.
void	setState(int state)	Sets the lifecycle state of this bean.
void	start()	start the service
protected void	startService()	Called during the start lifecycle phase; subclasses may override.
void	stop()	stop the service

Methods inherited from class Object

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

Constructor Details

QSingleInstanceFileBasedManager

public QSingleInstanceFileBasedManager()

Default constructor; no instance state to initialise.

Method Details

initService

protected void initService()
                    throws Exception

Description copied from class: QBeanSupport

Called during the init lifecycle phase; subclasses may override.

Overrides:

initService in class QBeanSupport

Throws:

Exception - on error

stopService

protected void stopService()
                    throws Exception

Description copied from class: QBeanSupport

Called during the stop lifecycle phase; subclasses may override.

Overrides:

stopService in class QBeanSupport

Throws:

Exception - on error