com.redhat.rhn.taskomatic.core

Class BaseDaemon

java.lang.Object

com.redhat.rhn.taskomatic.core.BaseDaemon

All Implemented Interfaces:

org.tanukisoftware.wrapper.WrapperListener

Direct Known Subclasses:

TaskomaticDaemon, TestDaemon

public abstract class BaseDaemon
extends java.lang.Object
implements org.tanukisoftware.wrapper.WrapperListener

This is the base implementation for all RHN Java daemons. It serves at the interface between the Tanuki service/daemon wrapper library and also provides very basic lifecycle callbacks.

Field Summary

Fields

Modifier and Type	Field and Description
static int	LOG_DEBUG
static int	LOG_ERROR
static int	LOG_FATAL
static int	LOG_INFO
static int	LOG_STATUS
static int	SUCCESS

Constructor Summary

Constructors

Constructor and Description
BaseDaemon()

Method Summary

Modifier and Type	Method and Description
protected org.apache.commons.cli.Options	buildOptionsList() Creates the "master" list of options which the daemon implementation knows about.
void	controlEvent(int event) Interface method required by WrapperListener
void	logMessage(int logLevel, java.lang.String msg, java.lang.Throwable err) Convenience method to allow daemon implementations to log messages directly to the host system's system log, ie not log4j or commons-logging.
protected int	onOptionsParseError(org.apache.commons.cli.ParseException e) Lifecycle method called when startup parameters cannot be parsed.
protected abstract int	onShutdown(boolean breakFromUser) Lifecycle method called when the daemon implementation is stopped.
protected abstract int	onStartup(org.apache.commons.cli.CommandLine commandLine) Lifecycle method called when the daemon implementation is started.
protected void	registerImplementation(java.lang.String[] argv) Registers the daemon implementation with the Tanuki wrapper
java.lang.Integer	start(java.lang.String[] argv) Interface method required by WrapperListener
int	stop(int code) Interface method required by WrapperListener

Methods inherited from class java.lang.Object

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

Field Detail

LOG_DEBUG

public static final int LOG_DEBUG

See Also:

Constant Field Values

LOG_INFO

public static final int LOG_INFO

See Also:

Constant Field Values

LOG_ERROR

public static final int LOG_ERROR

See Also:

Constant Field Values

LOG_FATAL

public static final int LOG_FATAL

See Also:

Constant Field Values

LOG_STATUS

public static final int LOG_STATUS

See Also:

Constant Field Values

SUCCESS

public static final int SUCCESS

See Also:

Constant Field Values

Constructor Detail

BaseDaemon

public BaseDaemon()

Method Detail

start

public java.lang.Integer start(java.lang.String[] argv)

Interface method required by WrapperListener

Specified by:

start in interface org.tanukisoftware.wrapper.WrapperListener

Parameters:

argv - Arguments configured in the daemon's config file

Returns:

Integer indicating status (null indicates success, else value indicates error code)

stop

public int stop(int code)

Interface method required by WrapperListener

Specified by:

stop in interface org.tanukisoftware.wrapper.WrapperListener

Parameters:

code - int

Returns:

int

controlEvent

public void controlEvent(int event)

Interface method required by WrapperListener

Specified by:

controlEvent in interface org.tanukisoftware.wrapper.WrapperListener

Parameters:

event - int

logMessage

public void logMessage(int logLevel,
                       java.lang.String msg,
                       java.lang.Throwable err)

Convenience method to allow daemon implementations to log messages directly to the host system's system log, ie not log4j or commons-logging. If a java.lang.Throwable is passed in then the stack trace will be logged as well.

Parameters:

logLevel - Desired log level

msg - Message to log

err - Optional

registerImplementation

protected void registerImplementation(java.lang.String[] argv)

Registers the daemon implementation with the Tanuki wrapper

Parameters:

argv - startup parameters (if any)

buildOptionsList

protected org.apache.commons.cli.Options buildOptionsList()

Creates the "master" list of options which the daemon implementation knows about. Implementations should override this method if they need param parsing.

Returns:

org.apache.commons.cli.Options instance populated with options or null if no options

onOptionsParseError

protected int onOptionsParseError(org.apache.commons.cli.ParseException e)

Lifecycle method called when startup parameters cannot be parsed. This gives the daemon implementation an opportunity to do something about the error such as display a usage message.

Parameters:

e - the ParseException

Returns:

int indicates error code. If BaseDaemon.SUCCESS is returned, then the framework will still try to start the daemon implementation _without_ parameters.

onStartup

protected abstract int onStartup(org.apache.commons.cli.CommandLine commandLine)

Lifecycle method called when the daemon implementation is started. This method _must_ return otherwise the daemon will appear to hang at startup. This implies that all "real" work needs to be done in a separate thread.

Parameters:

commandLine - Parsed params, if present. Otherwise null.

Returns:

int indicates status where BaseDaemon.SUCCESS indicates success and any other number indicates failure

onShutdown

protected abstract int onShutdown(boolean breakFromUser)

Lifecycle method called when the daemon implementation is stopped.

Parameters:

breakFromUser - True if the user sent a Ctrl-C

Returns:

int indicates status where BaseDaemon.SUCCESS indicates success and any other number indicates an error