Package org.apache.commons.daemon.support

Class DaemonWrapper

java.lang.Object

org.apache.commons.daemon.support.DaemonWrapper

All Implemented Interfaces:

Daemon

public class DaemonWrapper
extends java.lang.Object
implements Daemon

Implementation of the Daemon that allows running standard applications as daemons. The applications must have the mechanism to manage the application lifecycle.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	DaemonWrapper.Invoker

Field Summary

Fields

Modifier and Type	Field	Description
private static java.lang.String	ARGS
private DaemonConfiguration	config
private java.lang.String	configFileName
private DaemonWrapper.Invoker	shutdown
private static java.lang.String	START_CLASS
private static java.lang.String	START_METHOD
private DaemonWrapper.Invoker	startup
private static java.lang.String	STOP_ARGS
private static java.lang.String	STOP_CLASS
private static java.lang.String	STOP_METHOD

Constructor Summary

Constructors

Constructor	Description
DaemonWrapper()

Method Summary

Modifier and Type	Method	Description
void	destroy()	Frees any resources allocated by this daemon such as file descriptors or sockets.
void	init(DaemonContext context)	Called from DaemonLoader on init stage.
void	start()	Starts the operation of this Daemon instance.
void	stop()	Stops the operation of this Daemon instance.

Methods inherited from class java.lang.Object

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

Field Detail

ARGS

private static final java.lang.String ARGS

See Also:

Constant Field Values

START_CLASS

private static final java.lang.String START_CLASS

See Also:

Constant Field Values

START_METHOD

private static final java.lang.String START_METHOD

See Also:

Constant Field Values

STOP_CLASS

private static final java.lang.String STOP_CLASS

See Also:

Constant Field Values

STOP_METHOD

private static final java.lang.String STOP_METHOD

See Also:

Constant Field Values

STOP_ARGS

private static final java.lang.String STOP_ARGS

See Also:

Constant Field Values

configFileName

private java.lang.String configFileName

config

private final DaemonConfiguration config

startup

private final DaemonWrapper.Invoker startup

shutdown

private final DaemonWrapper.Invoker shutdown

Constructor Detail

DaemonWrapper

public DaemonWrapper()

Method Detail

init

public void init(DaemonContext context)
          throws java.lang.Exception

Called from DaemonLoader on init stage.

Accepts the following configuration arguments:

• -daemon-properties: - load DaemonConfiguration properties from the specified file to act as defaults
• -start: set start class name
• -start-method: set start method name
• -stop: set stop class name
• -stop-method: set stop method name
• -stop-argument: set optional argument to stop method
• Anything else is treated as a startup argument

The following "-daemon-properties" are recognized:

• args (startup argument)
• start
• start.method
• stop
• stop.method
• stop.args

These are used to set the corresponding item if it has not already been set by the command arguments. However, note that args and stop.args are appended to any existing values.

Specified by:

init in interface Daemon

Parameters:

context - A DaemonContext object used to communicate with the container.

Throws:

DaemonInitException - An exception that prevented initialization where you want to display a nice message to the user, rather than a stack trace.

java.lang.Exception - Any exception preventing a successful initialization.

start

public void start()
           throws java.lang.Exception

Description copied from interface: Daemon

Starts the operation of this Daemon instance. This method is to be invoked by the environment after the init() method has been successfully invoked and possibly the security level of the JVM has been dropped. Implementors of this method are free to start any number of threads, but need to return control after having done that to enable invocation of the stop()-method.

Specified by:

start in interface Daemon

Throws:

java.lang.Exception - If the start was not successful

stop

public void stop()
          throws java.lang.Exception

Description copied from interface: Daemon

Stops the operation of this Daemon instance. Note that the proper place to free any allocated resources such as sockets or file descriptors is in the destroy method, as the container may restart the Daemon by calling start() after stop().

Specified by:

stop in interface Daemon

Throws:

java.lang.Exception - If the stop was not successful

destroy

public void destroy()

Description copied from interface: Daemon

Frees any resources allocated by this daemon such as file descriptors or sockets. This method gets called by the container after stop() has been called, before the JVM exits. The Daemon can not be restarted after this method has been called without a new call to the init() method.

Specified by:

destroy in interface Daemon