org.eclipse.scada.da.utils.daemon

Class ExporterDaemon

java.lang.Object

org.eclipse.scada.da.utils.daemon.ExporterDaemon

All Implemented Interfaces:

org.apache.commons.daemon.Daemon

public class ExporterDaemon
extends Object
implements org.apache.commons.daemon.Daemon

Wrapping the exporter controller into a jakarta daemon

Author:

Jens Reimann

See Also:

Daemon

Constructor Summary

Constructors

Constructor and Description
ExporterDaemon()

Method Summary

Modifier and Type	Method and Description
void	destroy() Frees any resources allocated by this daemon such as file descriptors or sockets.
void	init(org.apache.commons.daemon.DaemonContext ctx) Initializes this Daemon instance.
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

Constructor Detail

ExporterDaemon

public ExporterDaemon()

Method Detail

destroy

public void destroy()

Description copied from interface: org.apache.commons.daemon.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 org.apache.commons.daemon.Daemon

init

public void init(org.apache.commons.daemon.DaemonContext ctx)
          throws Exception

Description copied from interface: org.apache.commons.daemon.Daemon

Initializes this Daemon instance.

This method gets called once the JVM process is created and the Daemon instance is created thru its empty public constructor.

Under certain operating systems (typically Unix based operating systems) and if the native invocation framework is configured to do so, this method might be called with super-user privileges.

For example, it might be wise to create ServerSocket instances within the scope of this method, and perform all operations requiring super-user privileges in the underlying operating system.

Apart from set up and allocation of native resources, this method must not start the actual operation of the Daemon (such as starting threads calling the ServerSocket.accept() method) as this would impose some serious security hazards. The start of operation must be performed in the start() method.

Specified by:

init in interface org.apache.commons.daemon.Daemon

Parameters:

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

Throws:

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

Exception - Any exception preventing a successful initialization.

start

public void start()
           throws Exception

Description copied from interface: org.apache.commons.daemon.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 org.apache.commons.daemon.Daemon

Throws:

Exception

stop

public void stop()
          throws Exception

Description copied from interface: org.apache.commons.daemon.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 org.apache.commons.daemon.Daemon

Throws:

Exception