org.sensorhub.impl.module

Class AbstractModule<ConfigType extends ModuleConfig>

java.lang.Object

org.sensorhub.impl.module.AbstractModule<ConfigType>

Type Parameters:

ConfigType -

All Implemented Interfaces:

IEventProducer, IModule<ConfigType>

Direct Known Subclasses:

AbstractSensorModule, AbstractStreamProcess, AdminUIModule, BasicSecurityRealm, BasicStorageImpl, GenericStreamStorage, HttpServer, InMemoryBasicStorage, SOSService, SOSTClient, SPSService, TCPCommProvider, UDPCommProvider

public abstract class AbstractModule<ConfigType extends ModuleConfig>
extends Object
implements IModule<ConfigType>

Class providing default implementation of common module API methods

Since:

Oct 30, 2014

Author:

Alex Robin

Field Summary

Fields

Modifier and Type	Field and Description
protected ConfigType	config
protected IEventHandler	eventHandler
protected Throwable	lastError
protected org.slf4j.Logger	logger
protected ModuleSecurity	securityHandler
protected boolean	startRequested
protected ModuleEvent.ModuleState	state
protected Object	stateLock
protected String	statusMsg

Constructor Summary

Constructors

Constructor and Description
AbstractModule()

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	canInit(boolean force)
protected boolean	canStart()
protected boolean	canStop()
void	clearError() Clears last error
void	clearStatus() Clears the current status message
ConfigType	getConfiguration() Retrieves a copy of the module configuration (i.e.
Throwable	getCurrentError()
ModuleEvent.ModuleState	getCurrentState()
String	getLocalID() Helper method to get the module's local ID
org.slf4j.Logger	getLogger()
String	getName() Helper method to get the module's name
String	getStatusMessage()
void	init() Initializes the module synchronously with the current configuration. Implementations of this method must block until the module is successfully initialized or send an exception. Module lifecycle events may not be generated when calling this method directly.
void	init(ConfigType config) Initializes the module synchronously with the specified configuration. Implementations of this method must block until the module is successfully initialized or send an exception. This is equivalent to calling IModule.setConfiguration(ModuleConfig) and then IModule.init() with no arguments. Module lifecycle events may not be generated when calling this method directly.
boolean	isInitialized() Checks if module is initialized
boolean	isStarted() Checks if module is started
void	loadState(IModuleStateManager loader) Restores the state of this module Implementations of this method must block until the module state is successfully loaded or send an exception.
protected void	notifyConnectionStatus(boolean connected, String remoteServiceName) Helper method to send and log connection/disconnection events
void	registerListener(IEventListener listener) Registers a listener to receive events generated by this module. When this method is called, the current state of the module is also notified synchronously to guarantee that the listener always receives it.
void	reportError(String msg, Throwable error) Sets the module error state and sends corresponding event
void	reportError(String msg, Throwable error, boolean logAsDebug) Sets the module error state and sends corresponding event
void	reportStatus(String msg) Sets the module status message and sends corresponding event
void	requestInit(boolean force) Requests to initialize the module with the current configuration. Implementations of this method block until the module is initialized or return immediately while they wait for the proper init conditions. When this method returns without error the module state is guaranteed to be ModuleEvent.ModuleState.INITIALIZING
void	requestStart() Requests the module to start. Implementations of this method may block until the module is started or return immediately while they wait for the proper start conditions. When this method returns without error the module state is guaranteed to be ModuleEvent.ModuleState.STARTING
void	requestStop() Requests the module to stop. Implementations of this method may block until the module is stopped or return immediately while they wait for the proper stop conditions. When this method returns without error the module state is guaranteed to be ModuleEvent.ModuleState.STOPPING
void	saveState(IModuleStateManager saver) Saves the state of this module. Implementations of this method must block until the module state is successfully saved or send an exception.
void	setConfiguration(ConfigType config) Sets the module configuration
protected void	setState(ModuleEvent.ModuleState newState) Sets the module state and sends the appropriate event if it has changed
String	toString()
void	unregisterListener(IEventListener listener) Unregisters a listener and thus stop receiving events generayed by this module
void	updateConfig(ConfigType config) Updates the module's configuration dynamically. The module must honor this new configuration unless an error is detected.
boolean	waitForState(ModuleEvent.ModuleState state, long timeout) Waits until the module reaches the specified state or times out. This method will return immediately if the state has already been reached.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.sensorhub.api.module.IModule

cleanup, start, stop

Field Detail

logger

protected org.slf4j.Logger logger

eventHandler

protected IEventHandler eventHandler

config

protected ConfigType extends ModuleConfig config

state

protected ModuleEvent.ModuleState state

securityHandler

protected ModuleSecurity securityHandler

stateLock

protected final Object stateLock

startRequested

protected boolean startRequested

lastError

protected Throwable lastError

statusMsg

protected String statusMsg

Constructor Detail

AbstractModule

public AbstractModule()

Method Detail

getName

public String getName()

Description copied from interface: IModule

Helper method to get the module's name

Specified by:

getName in interface IModule<ConfigType extends ModuleConfig>

Returns:

name string

getLocalID

public String getLocalID()

Description copied from interface: IModule

Helper method to get the module's local ID

Specified by:

getLocalID in interface IModule<ConfigType extends ModuleConfig>

Returns:

id string

getConfiguration

public ConfigType getConfiguration()

Description copied from interface: IModule

Retrieves a copy of the module configuration (i.e. for reading only since changes won't have any effect until updateConfig is called)

Specified by:

getConfiguration in interface IModule<ConfigType extends ModuleConfig>

Returns:

a copy of the configuration object associated to this module

setConfiguration

public void setConfiguration(ConfigType config)

Description copied from interface: IModule

Sets the module configuration

Specified by:

setConfiguration in interface IModule<ConfigType extends ModuleConfig>

updateConfig

public void updateConfig(ConfigType config)
                  throws SensorHubException

Description copied from interface: IModule

Updates the module's configuration dynamically.
The module must honor this new configuration unless an error is detected. It is the responsability of the module to initiate a restart if the new configuration requires it.

Specified by:

updateConfig in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException

isInitialized

public boolean isInitialized()

Description copied from interface: IModule

Checks if module is initialized

Specified by:

isInitialized in interface IModule<ConfigType extends ModuleConfig>

Returns:

true if module is initialized, false otherwise

isStarted

public boolean isStarted()

Description copied from interface: IModule

Checks if module is started

Specified by:

isStarted in interface IModule<ConfigType extends ModuleConfig>

Returns:

true if module is started, false otherwise

getCurrentState

public ModuleEvent.ModuleState getCurrentState()

Specified by:

getCurrentState in interface IModule<ConfigType extends ModuleConfig>

Returns:

the current state of the module

setState

protected void setState(ModuleEvent.ModuleState newState)

Sets the module state and sends the appropriate event if it has changed

Parameters:

newState -

waitForState

public boolean waitForState(ModuleEvent.ModuleState state,
                   long timeout)

Description copied from interface: IModule

Waits until the module reaches the specified state or times out.
This method will return immediately if the state has already been reached.

Specified by:

waitForState in interface IModule<ConfigType extends ModuleConfig>

Parameters:

state - state to wait for

timeout - maximum time to wait in milliseconds or <= 0 to wait forever

Returns:

true if module state has been reached, false in case of timeout or error

getCurrentError

public Throwable getCurrentError()

Specified by:

getCurrentError in interface IModule<ConfigType extends ModuleConfig>

Returns:

the last error that occured executing the module

reportError

public void reportError(String msg,
               Throwable error)

Sets the module error state and sends corresponding event

Parameters:

msg -

error - false to log only at debug level

reportError

public void reportError(String msg,
               Throwable error,
               boolean logAsDebug)

Sets the module error state and sends corresponding event

Parameters:

msg -

error -

logAsDebug - set to true to log the exception only at debug level, false to log at error level

clearError

public void clearError()

Clears last error

getStatusMessage

public String getStatusMessage()

Specified by:

getStatusMessage in interface IModule<ConfigType extends ModuleConfig>

Returns:

the current status message

reportStatus

public void reportStatus(String msg)

Sets the module status message and sends corresponding event

Parameters:

msg -

clearStatus

public void clearStatus()

Clears the current status message

notifyConnectionStatus

protected void notifyConnectionStatus(boolean connected,
                          String remoteServiceName)

Helper method to send and log connection/disconnection events

Parameters:

connected -

canInit

protected boolean canInit(boolean force)
                   throws SensorHubException

Throws:

SensorHubException

requestInit

public void requestInit(boolean force)
                 throws SensorHubException

Description copied from interface: IModule

Requests to initialize the module with the current configuration.
Implementations of this method block until the module is initialized or return immediately while they wait for the proper init conditions.
When this method returns without error the module state is guaranteed to be ModuleEvent.ModuleState.INITIALIZING

Specified by:

requestInit in interface IModule<ConfigType extends ModuleConfig>

Parameters:

force - set to true to force a reinit, even if module was already initialized

Throws:

SensorHubException - if module could not enter initialization phase

init

public void init()
          throws SensorHubException

Description copied from interface: IModule

Initializes the module synchronously with the current configuration.
Implementations of this method must block until the module is successfully initialized or send an exception.
Module lifecycle events may not be generated when calling this method directly.

Specified by:

init in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException

init

public void init(ConfigType config)
          throws SensorHubException

Description copied from interface: IModule

Initializes the module synchronously with the specified configuration.
Implementations of this method must block until the module is successfully initialized or send an exception.
This is equivalent to calling IModule.setConfiguration(ModuleConfig) and then IModule.init() with no arguments.
Module lifecycle events may not be generated when calling this method directly.

Specified by:

init in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException

canStart

protected boolean canStart()
                    throws SensorHubException

Throws:

SensorHubException

requestStart

public void requestStart()
                  throws SensorHubException

Description copied from interface: IModule

Requests the module to start.
Implementations of this method may block until the module is started or return immediately while they wait for the proper start conditions.
When this method returns without error the module state is guaranteed to be ModuleEvent.ModuleState.STARTING

Specified by:

requestStart in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException - if startup could not be initiated

canStop

protected boolean canStop()
                   throws SensorHubException

Throws:

SensorHubException

requestStop

public void requestStop()
                 throws SensorHubException

Description copied from interface: IModule

Requests the module to stop.
Implementations of this method may block until the module is stopped or return immediately while they wait for the proper stop conditions.
When this method returns without error the module state is guaranteed to be ModuleEvent.ModuleState.STOPPING

Specified by:

requestStop in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException - if shutdown could not be initiated

saveState

public void saveState(IModuleStateManager saver)
               throws SensorHubException

Description copied from interface: IModule

Saves the state of this module.
Implementations of this method must block until the module state is successfully saved or send an exception.

Specified by:

saveState in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException

loadState

public void loadState(IModuleStateManager loader)
               throws SensorHubException

Description copied from interface: IModule

Restores the state of this module
Implementations of this method must block until the module state is successfully loaded or send an exception.

Specified by:

loadState in interface IModule<ConfigType extends ModuleConfig>

Throws:

SensorHubException

registerListener

public void registerListener(IEventListener listener)

Description copied from interface: IModule

Registers a listener to receive events generated by this module.
When this method is called, the current state of the module is also notified synchronously to guarantee that the listener always receives it.

Specified by:

registerListener in interface IEventProducer

Specified by:

registerListener in interface IModule<ConfigType extends ModuleConfig>

unregisterListener

public void unregisterListener(IEventListener listener)

Description copied from interface: IModule

Unregisters a listener and thus stop receiving events generayed by this module

Specified by:

unregisterListener in interface IEventProducer

Specified by:

unregisterListener in interface IModule<ConfigType extends ModuleConfig>

getLogger

public org.slf4j.Logger getLogger()

toString

public String toString()

Overrides:

toString in class Object