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Posted to dev@turbine.apache.org by se...@apache.org on 2003/09/16 06:43:02 UTC
cvs commit: jakarta-turbine-2/xdocs/howto services-howto.xml
seade 2003/09/15 21:43:02
Modified: xdocs/howto services-howto.xml
Log:
Removed reference to service that no longer exists.
Revision Changes Path
1.2 +1 -1 jakarta-turbine-2/xdocs/howto/services-howto.xml
Index: services-howto.xml
===================================================================
RCS file: /home/cvs/jakarta-turbine-2/xdocs/howto/services-howto.xml,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- services-howto.xml 30 Jan 2003 00:32:12 -0000 1.1
+++ services-howto.xml 16 Sep 2003 04:43:02 -0000 1.2
@@ -1 +1 @@
-<?xml version="1.0"?>
<document>
<properties>
<title>Services Howto</title>
<author email="hps@intermeta.de">Henning P. Schmiedehausen</author>
<author email="matt@orkan.no">Matt Koranda</author>
</properties>
<body>
<section name="Turbine Services Creation">
<p>
Adding your own services to Turbine is an easy task. Simply make your
class extend <b>org.apache.turbine.services.TurbineBaseService</b>.
This is necessary so that the Turbine Service Broker can start up
your service.
</p>
<p>
To make it known to the Turbine itself, you must configure it in
the TurbineResources.properties like this:
<source>
services.MyServiceName.classname = full.class.name.of.your.service
</source>
</p>
<p>
and you're set, Turbine will now initialize the service if it is
requested by an application. Please be aware that your service is
<b>not</b> initialized right at Startup. This is called lazy init.
If you need your Service to start up right away, you must add another
property to the TurbineResources.properties:
<source>
services.MyServiceName.earlyInit = true
</source>
</p>
<p>
If you look at the examples of the simple services like
db/TurbinePoolBrokerService or servlet/TurbineServletService you'll
get on speed pretty fast.
</p>
</section>
<section name="In a Nutshell">
<p>
<ul>
<li>
You must not try to provide a constructor with parameters, best is
not to provide any constructor at all, because nothing should be
done at construction time (You'll get the default constructor which
is fine for us).
</li>
<li>
Your Service will be instantiated exactly once. So it must be
threadsafe and must not use class global variables for
session-dependend information.
</li>
<li>
You should provide an init() method which is called when your
service is requested for the first time (or at startup if you
set earlyInit = true) and should initialize your service
dependent code. There is lots of confusion of how this init()
method should look like because Turbine used different methods
of Service initialization. Beginning with Turbine 2.2, you should
only use the parameterless variant:
</li>
</ul>
</p>
<source>
public void init() throws InitializationException
{
}
</source>
<p>
<ul>
<li>
You <b>must</b> call setInit(true) if your service initializes
correctly. Otherwise no user of your service can request it.
Right after this, your service might be queried and used by other
sessions, so you should not call setInit() prematurely.
</li>
<li>
You might provide a shutdown() method which is called when
Turbine shuts down. You can clean up your internal data in this
method. You should call setInit(false) as the last thing in
shutdown().
</li>
</ul>
</p>
</section>
<section name="Style">
<p>
It is good style, that if you build the FooService, to provide
<b>your.package.FooService.java</b> with an Interface definition of
your service which extends <b>org.apache.turbine.services.Service</b>
It should contain a constant SERVICE_NAME with the Turbine visible
name of your service like this:
<source>
package your.package;
import org.apache.turbine.services.Service;
public interface FooService extends Service
{
/**
* The service identifier
*/
public String SERVICE_NAME = "FooService";
[...]
}
</source>
</p>
<p>
<b>your.package.TurbineFooService.java</b> which extends the
<b>org.apache.turbine.services.TurbineBaseService</b> class and
implements <b>your.package.FooService</b> and provides the actual code:
</p>
<source>
package your.package;
import org.apache.turbine.services.TurbineBaseService;
public class TurbineFooService
extends TurbineBaseService
implements FooService
{
/**
* Service logic here
*/
[...]
}
</source>
<p>
<b>your.package.TurbineFoo.java</b> which contains static facade
methods for your service along the following lines:
<source>
import org.apache.turbine.services.TurbineServices;
public class TurbineFoo
{
protected static FooService getService()
{
return (FooService) TurbineServices
.getInstance().getService(FooService.SERVICE_NAME);
}
[...]
public static void fooMethod1()
{
getService().fooMethod1();
}
public static int fooMethod2(int bar)
{
return getService().fooMethod2(bar);
}
[...]
}
</source>
</p>
<p>
to give users of your service the ability to simply write:
<source>
TurbineFoo.fooMethod1();
</source>
</p>
<p>
in their code and not to care about which actual Implementation of
FooService is running.
</p>
<p>
init() and shutdown() applies to Turbine 2.1/2.2 This might change
with the lifecycle interfaces in a later release.
</p>
</section>
</body>
</document>
\ No newline at end of file
+<?xml version="1.0"?>
<document>
<properties>
<title>Services Howto</title>
<author email="hps@intermeta.de">Henning P. Schmiedehausen</author>
<author email="matt@orkan.no">Matt Koranda</author>
</properties>
<body>
<section name="Turbine Services Creation">
<p>
Adding your own services to Turbine is an easy task. Simply make your
class extend <b>org.apache.turbine.services.TurbineBaseService</b>.
This is necessary so that the Turbine Service Broker can start up
your service.
</p>
<p>
To make it known to the Turbine itself, you must configure it in
the TurbineResources.properties like this:
<source>
services.MyServiceName.classname = full.class.name.of.your.service
</source>
</p>
<p>
and you're set, Turbine will now initialize the service if it is
requested by an application. Please be aware that your service is
<b>not</b> initialized right at Startup. This is called lazy init.
If you need your Service to start up right away, you must add another
property to the TurbineResources.properties:
<source>
services.MyServiceName.earlyInit = true
</source>
</p>
<p>
If you look at the examples of the simple services like
servlet/TurbineServletService you'll get on speed pretty fast.
</p>
</section>
<section name="In a Nutshell">
<p>
<ul>
<li>
You must not try to provide a constructor with parameters, best is
not to provide any constructor at all, because nothing should be
done at construction time (You'll get the default constructor which
is fine for us).
</li>
<li>
Your Service will be instantiated exactly once. So it must be
threadsafe and must not use class global variables for
session-dependend information.
</li>
<li>
You should provide an init() method which is called when your
service is requested for the first time (or at startup if you
set earlyInit = true) and should initialize your service
dependent code. There is lots of confusion of how this init()
method should look like because Turbine used different methods
of Service initialization. Beginning with Turbine 2.2, you should
only use the parameterless variant:
</li>
</ul>
</p>
<source>
public void init() throws InitializationException
{
}
</source>
<p>
<ul>
<li>
You <b>must</b> call setInit(true) if your service initializes
correctly. Otherwise no user of your service can request it.
Right after this, your service might be queried and used by other
sessions, so you should not call setInit() prematurely.
</li>
<li>
You might provide a shutdown() method which is called when
Turbine shuts down. You can clean up your internal data in this
method. You should call setInit(false) as the last thing in
shutdown().
</li>
</ul>
</p>
</section>
<section name="Style">
<p>
It is good style, that if you build the FooService, to provide
<b>your.package.FooService.java</b> with an Interface definition of
your service which extends <b>org.apache.turbine.services.Service</b>
It should contain a constant SERVICE_NAME with the Turbine visible
name of your service like this:
<source>
package your.package;
import org.apache.turbine.services.Service;
public interface FooService extends Service
{
/**
* The service identifier
*/
public String SERVICE_NAME = "FooService";
[...]
}
</source>
</p>
<p>
<b>your.package.TurbineFooService.java</b> which extends the
<b>org.apache.turbine.services.TurbineBaseService</b> class and
implements <b>your.package.FooService</b> and provides the actual code:
</p>
<source>
package your.package;
import org.apache.turbine.services.TurbineBaseService;
public class TurbineFooService
extends TurbineBaseService
implements FooService
{
/**
* Service logic here
*/
[...]
}
</source>
<p>
<b>your.package.TurbineFoo.java</b> which contains static facade
methods for your service along the following lines:
<source>
import org.apache.turbine.services.TurbineServices;
public class TurbineFoo
{
protected static FooService getService()
{
return (FooService) TurbineServices
.getInstance().getService(FooService.SERVICE_NAME);
}
[...]
public static void fooMethod1()
{
getService().fooMethod1();
}
public static int fooMethod2(int bar)
{
return getService().fooMethod2(bar);
}
[...]
}
</source>
</p>
<p>
to give users of your service the ability to simply write:
<source>
TurbineFoo.fooMethod1();
</source>
</p>
<p>
in their code and not to care about which actual Implementation of
FooService is running.
</p>
<p>
init() and shutdown() applies to Turbine 2.1/2.2 This might change
with the lifecycle interfaces in a later release.
</p>
</section>
</body>
</document>
\ No newline at end of file