geirm 01/03/30 21:29:10
Modified: xdocs developer-guide.xml
docs developer-guide.html
Log:
Added note about the new parser.pool.size property, and more information
on configuration of resource loaders and logging. Not done. Wanted
to get in...
Revision Changes Path
1.33 +298 -2 jakarta-velocity/xdocs/developer-guide.xml
Index: developer-guide.xml
===================================================================
RCS file: /home/cvs/jakarta-velocity/xdocs/developer-guide.xml,v
retrieving revision 1.32
retrieving revision 1.33
diff -u -r1.32 -r1.33
--- developer-guide.xml 2001/03/22 17:09:53 1.32
+++ developer-guide.xml 2001/03/31 05:29:09 1.33
@@ -54,7 +54,8 @@
<li><a href="developer-guide.html#velocityclass">The Velocity Helper Class</a></li>
<li><a href="developer-guide.html#exceptions">Exceptions</a></li>
<li><a href="developer-guide.html#generalmisc">Miscellaneous</a></li>
-</ul></li>
+</ul>
+</li>
<li>
<a href="developer-guide.html#config">Configuration Keys and Values</a>
@@ -62,6 +63,20 @@
<li>
<a href="developer-guide.html#logging">Configuring the Log System</a>
+ <ul>
+ <li>
+ <a href="developer-guide.html#customlogging">Simple Example of a Custom
Logger</a>
+ </li>
+ </ul>
+</li>
+
+<li>
+<a href="developer-guide.html#loaders">Configuring the Resource Loaders (template
loaders)</a>
+<ul>
+ <li>
+ <a href="developer-guide.html#resourceexamples">Configuration Examples</a>
+ </li>
+ </ul>
</li>
<li>
@@ -140,7 +155,7 @@
<li>
<code>jar-j2ee</code> builds a complete jar, like the 'jar' target,
that includes any components that require J2EE support. Currently, this
- includes only
org.apache.velocity.runtime.resource.loader.DataResourceLoader.
+ includes only
org.apache.velocity.runtime.resource.loader.DataSourceResourceLoader.
As usual, it is placed in the <code>bin</code> directory, called
'velocity-j2ee-X.jar'. NOTE : if you wish to use this build target, you
must place (or link) a copy of j2ee.jar into the build/lib directory.
@@ -1312,6 +1327,22 @@
or as an argument to a VTL directive in general. See the VTL reference for
further information.
</p>
+
+<strong>Runtime Configuration</strong>
+<p>
+<code>parser.pool.size = 20</code><br/>
+This property sets the number of parsers that Velocity will
+create at startup and keep in a pool. The default of 20 parsers
+should be more than enough for most uses. In the event
+that Velocity does run out of parsers, it will indicate
+so in the log, and
+dynamically create them as needed. Note that they will not
+be added to the pool. This is a slow operation compared to
+the normal parser pooling, but this is considered an
+exceptional condition. If you see a log message, please
+increment this property.
+</p>
+
</section>
<section name="Configuring the Log System">
@@ -1365,8 +1396,273 @@
</ul>
</p>
+<p>
+Making a custom logger class if very simple. The code below is a
+simple sketch of how you might do this in your own application.
+</p>
+
+<strong>Simple Example of a Custom Logger</strong>
+<a name="customlogging"></a>
+<p>
+Here is a simple example of how to integrate Velocity's logging system into your
own application.
+</p>
+<source><![CDATA[
+
+import org.apache.velocity.runtime.log.LogSystem;
+
+...
+
+public class MyClass implements LogSystem
+{
+
+...
+
+ public MyClass()
+ {
+ ...
+
+ try
+ {
+ /*
+ * register this class as a logger
+ */
+
+ Velocity.setProperty(Velocity.RUNTIME_LOG_LOGSYSTEM, this );
+ Velocity.init();
+ }
+ catch (Exception e)
+ {
+ /*
+ * do something
+ */
+ }
+ }
+
+ /**
+ * This is the method that you implement for Velocity to call
+ * with log messages.
+ */
+ public void logVelocityMessage(int level, String message)
+ {
+ /* do something useful */
+ }
+...
+}
+
+]]></source>
+
</section>
+<section name="Configuring Resource Loaders">
+<a name="loaders"></a>
+
+<p>
+One of the fundamental and important parts about Velocity is the resource
+management system and the resource loaders. They are referred to as 'resources'
+here rather than 'templates' because the resource management system will also
+handle non-template reasources, specifically things that are loaded via the
+#include() directive.
+</p>
+
+<p>
+The resource loader system if very flexible, allowing one or more resource
+loaders to be in operation at the same time. This allows tremendous
+flexibility in configuration and resource managment, and futher allows you
+to write your own resource loaders for your special needs.
+</p>
+
+<p>
+There are currently four kinds of resource loaders that are included with Velocity,
+each described below. Note that in the example configuration properties given,
+a common name for the loader is shown
+(ex.'file' in <code>file.resource.loader.path</code>). This 'common name'
+may not work for your configuration. Please read the section on
+<a href="developer-guide.html#config">resource configuration properties</a>
+ to understand how this system works. Also, each of these loaders is
+located in the package <code>org.apache.velocity.runtime.resource.loader</code>.
+<ul>
+<li>
+ <b>FileResourceLoader :</b> This loader gets resources from the filesystem. It's
+ configuration properties include :
+ <ul>
+ <li>
+ <code>file.resource.loader.path</code> = <path to root of templates>
+ </li>
+ <li>
+ <code>file.resource.loader.cache</code> = true/false
+ </li>
+ <li>
+ <code>file.resource.loader.modificationCheckInterval</code> = <seconds
between checks>
+ </li>
+ </ul>
+ This is the default loader, and is configured, by default to get templates from
the
+ 'current directory'. In the case of using Velocity with servlets, this can be a
problem
+ as you don't want to have to keep your templates in the directory from which you
start
+ your servlet engine. Please see the section on
+ <a href="developer-guide.html#servlets"> developing servlets with Velocity</a>
+ for more information.
+</li>
+<li>
+ <b>JarResourceLoader :</b> This loader gets resource from specific jar files. It
is very
+ similar to the FileResourceLoader, except that you have the convenience of
bundling
+ your templates into jars. The properties are identical, except for
+ <code>jar.resource.loader.path</code>, where you provide the full location of
+ the jar(s) you wish to load resources from.
+</li>
+<li>
+ <b>ClasspathResourceLoader :</b> This loader gets resources from the classloader.
While the
+ classpath is a source of great pain and suffering in general, it is a very useful
+ mechanism when working on a Servlet Spec 2.2 compliant servler runner.
+ <a href="http://jakarta.apache.org/tomcat/">Tomcat 3.2</a>
+ is an example of such. To use this loader effectively, all you must do is
+ jar your templates, and put that jar into the WEB-INF/lib directory of your
+ webapp. There are no configuration options to worry about, nor is the absolute
vs.
+ relative path an issue, as it is with Jar and File resource loaders.
+</li>
+
+<li>
+ <b>DataSourceResourceLoader :</b> This loader will load resources from a
DataSource
+such as a database. This loader is not built as part of the standard build
+as it requires J2EE support. To build this loader, please download the J2EE
+distribution, move the j2ee.jar into the <code>build/lib</code> directory,
+and then build the new velocity jar with the <code>jar-j2ee</code> build target.
+For more information on this loader, please see the javadoc for the class
+<code>org.apache.velocity.runtime.resource.loader.DataSourceResourceLoader</code>.
+</li>
+
+</ul>
+</p>
+
+<strong>Configuration Examples</strong>
+<a name="resourceexamples"></a>
+
+<p>
+Configuring the resource loaders for Velocity is straightforward.
+The properties that control the are listed in the
+<a href="developer-guide.html#config">resource configuration</a>
+section, for further reference.
+</p>
+
+<p>
+The first step in configuring one or more resource loaders is do
+'declare' them by name to Velocity. Use the property
+<code>resource.loader</code> and list one or more loader names.
+You can use anything you want - these names are used to associate
+configuration properties with a given loader.
+</p>
+
+<source><![CDATA[
+
+ resource.loader = file
+
+]]></source>
+
+
+<p>
+That entry declares that we will have a resource loader known as 'file'.
+The next thing to do is to set the important properties. The most critical
+is to declare the class to use as the loader :
+</p>
+
+<source><![CDATA[
+
+ file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+
+]]></source>
+
+<p>
+In this case, we are telling velocity that we are setting up
+a resource loadercalled 'file', and are using the class
+<code>
+org.apache.velocity.runtime.resource.loader.FileResourceLoader
+</code>
+to be the class to use.
+The next thing we do is set the properties important
+to this loader.
+</p>
+
+<source><![CDATA[
+file.resource.loader.path = /opt/templates
+file.resource.loader.cache = true
+file.resource.loader.modificationCheckInterval = 2
+]]></source>
+
+<p>
+Here, we set a few things. First, we set the path to find
+the templates to be <code>/opt/templates</code>. Second, we
+turned caching on, so that after a template or static file
+is read in, it is cached in memory. And finally, we set
+the modification check interval to 2 seconds, allowing Velocity
+to check for new templates.
+</p>
+
+<p>
+Those are the basics. What follows are a few examples of different configuraitons.
+</p>
+
+<p>
+<b>Do-nothing Default Configuration : </b> As the name says, there is nothing
+you have to do or configure to get the default configuration. This configuration
+uses the FileResourceLoader with the current directory as the default resource
+path, and caching is off. As a properties set, this is expressed as :
+</p>
+
+<source><![CDATA[
+resource.loader = file
+
+file.resource.loader.description = Velocity File Resource Loader
+file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+file.resource.loader.path = .
+file.resource.loader.cache = false
+file.resource.loader.modificationCheckInterval = 0
+]]></source>
+
+<p>
+<b>Multiple Template Path Configuration : </b> This configuration
+uses the FileResourceLoader with several directories as 'nodes' on the
+template search path. We also want to use caching, and have the templates
+checked for changes in 10 second intervals. As a properties set, this is expressed
as :
+</p>
+
+<source><![CDATA[
+resource.loader = file
+
+file.resource.loader.description = Velocity File Resource Loader
+file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+file.resource.loader.path = /opt/directory1, /opt/directory2
+file.resource.loader.cache = true
+file.resource.loader.modificationCheckInterval = 10
+]]></source>
+
+<p>
+<b>Dual Loader Configuration :</b> This configuration sets up
+two loaders at the same time, the FileResourceLoaderm, and
+the ClasspathResourceLoader. The loaders are set-up such that the
+FileResourceLoader is consulted first, and then the
+ClasspathResourceLoader. This would allow you to qickly
+drop a template into the file template are to replace on of the
+templates found in the classpath (usually via a jar) without
+having to rebuild the jar.
+</p>
+
+<source><![CDATA[
+resource.loader = file, class
+
+file.resource.loader.description = Velocity File Resource Loader
+file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+file.resource.loader.path = .
+file.resource.loader.cache = false
+file.resource.loader.modificationCheckInterval = 0
+
+class.resource.loader.description = Velocity Classpath Resource Loader
+class.resource.loader.class =
org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader
+]]></source>
+
+<p>
+Note that the ClasspathResourceLoader doesn't require much configuration.
+</p>
+
+</section>
<section name="Summary">
<a name="summary"></a>
1.49 +407 -2 jakarta-velocity/docs/developer-guide.html
Index: developer-guide.html
===================================================================
RCS file: /home/cvs/jakarta-velocity/docs/developer-guide.html,v
retrieving revision 1.48
retrieving revision 1.49
diff -u -r1.48 -r1.49
--- developer-guide.html 2001/03/27 00:39:15 1.48
+++ developer-guide.html 2001/03/31 05:29:10 1.49
@@ -152,7 +152,8 @@
<li><a href="developer-guide.html#velocityclass">The Velocity Helper Class</a></li>
<li><a href="developer-guide.html#exceptions">Exceptions</a></li>
<li><a href="developer-guide.html#generalmisc">Miscellaneous</a></li>
-</ul></li>
+</ul>
+</li>
<li>
<a href="developer-guide.html#config">Configuration Keys and Values</a>
@@ -160,6 +161,20 @@
<li>
<a href="developer-guide.html#logging">Configuring the Log System</a>
+ <ul>
+ <li>
+ <a href="developer-guide.html#customlogging">Simple Example of a Custom
Logger</a>
+ </li>
+ </ul>
+</li>
+
+<li>
+<a href="developer-guide.html#loaders">Configuring the Resource Loaders (template
loaders)</a>
+<ul>
+ <li>
+ <a href="developer-guide.html#resourceexamples">Configuration Examples</a>
+ </li>
+ </ul>
</li>
<li>
@@ -244,7 +259,7 @@
<li>
<code>jar-j2ee</code> builds a complete jar, like the 'jar' target,
that includes any components that require J2EE support. Currently, this
- includes only
org.apache.velocity.runtime.resource.loader.DataResourceLoader.
+ includes only
org.apache.velocity.runtime.resource.loader.DataSourceResourceLoader.
As usual, it is placed in the <code>bin</code> directory, called
'velocity-j2ee-X.jar'. NOTE : if you wish to use this build target, you
must place (or link) a copy of j2ee.jar into the build/lib directory.
@@ -1599,6 +1614,20 @@
or as an argument to a VTL directive in general. See the VTL reference for
further information.
</p>
+ <strong>Runtime
Configuration</strong>
+ <p>
+<code>parser.pool.size = 20</code><br />
+This property sets the number of parsers that Velocity will
+create at startup and keep in a pool. The default of 20 parsers
+should be more than enough for most uses. In the event
+that Velocity does run out of parsers, it will indicate
+so in the log, and
+dynamically create them as needed. Note that they will not
+be added to the pool. This is a slow operation compared to
+the normal parser pooling, but this is considered an
+exceptional condition. If you see a log message, please
+increment this property.
+</p>
</blockquote>
</td></tr>
</table>
@@ -1657,6 +1686,382 @@
<a href="developer-guide.html#config">configuration keys and values.</a>
</li>
</ul>
+</p>
+ <p>
+Making a custom logger class if very simple. The code below is a
+simple sketch of how you might do this in your own application.
+</p>
+ <strong>Simple Example of a Custom
Logger</strong>
+ <a name="customlogging" />
+ <p>
+Here is a simple example of how to integrate Velocity's logging system into your
own application.
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+
+import org.apache.velocity.runtime.log.LogSystem;
+
+...
+
+public class MyClass implements LogSystem
+{
+
+...
+
+ public MyClass()
+ {
+ ...
+
+ try
+ {
+ /*
+ * register this class as a logger
+ */
+
+ Velocity.setProperty(Velocity.RUNTIME_LOG_LOGSYSTEM, this );
+ Velocity.init();
+ }
+ catch (Exception e)
+ {
+ /*
+ * do something
+ */
+ }
+ }
+
+ /**
+ * This is the method that you implement for Velocity to call
+ * with log messages.
+ */
+ public void logVelocityMessage(int level, String message)
+ {
+ /* do something useful */
+ }
+...
+}
+
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ </blockquote>
+ </td></tr>
+ </table>
+ <table border="0" cellspacing="0"
cellpadding="2" width="100%">
+ <tr><td bgcolor="#525D76">
+ <font color="#ffffff" face="arial,helvetica,sanserif">
+ <a name="Configuring Resource Loaders"><strong>Configuring Resource
Loaders</strong></a>
+ </font>
+ </td></tr>
+ <tr><td>
+ <blockquote>
+ <a name="loaders" />
+ <p>
+One of the fundamental and important parts about Velocity is the resource
+management system and the resource loaders. They are referred to as 'resources'
+here rather than 'templates' because the resource management system will also
+handle non-template reasources, specifically things that are loaded via the
+#include() directive.
+</p>
+ <p>
+The resource loader system if very flexible, allowing one or more resource
+loaders to be in operation at the same time. This allows tremendous
+flexibility in configuration and resource managment, and futher allows you
+to write your own resource loaders for your special needs.
+</p>
+ <p>
+There are currently four kinds of resource loaders that are included with Velocity,
+each described below. Note that in the example configuration properties given,
+a common name for the loader is shown
+(ex.'file' in <code>file.resource.loader.path</code>). This 'common name'
+may not work for your configuration. Please read the section on
+<a href="developer-guide.html#config">resource configuration properties</a>
+ to understand how this system works. Also, each of these loaders is
+located in the package <code>org.apache.velocity.runtime.resource.loader</code>.
+<ul>
+<li>
+ <b>FileResourceLoader :</b> This loader gets resources from the filesystem. It's
+ configuration properties include :
+ <ul>
+ <li>
+ <code>file.resource.loader.path</code> = <path to root of templates>
+ </li>
+ <li>
+ <code>file.resource.loader.cache</code> = true/false
+ </li>
+ <li>
+ <code>file.resource.loader.modificationCheckInterval</code> = <seconds
between checks>
+ </li>
+ </ul>
+ This is the default loader, and is configured, by default to get templates from
the
+ 'current directory'. In the case of using Velocity with servlets, this can be a
problem
+ as you don't want to have to keep your templates in the directory from which you
start
+ your servlet engine. Please see the section on
+ <a href="developer-guide.html#servlets"> developing servlets with Velocity</a>
+ for more information.
+</li>
+<li>
+ <b>JarResourceLoader :</b> This loader gets resource from specific jar files. It
is very
+ similar to the FileResourceLoader, except that you have the convenience of
bundling
+ your templates into jars. The properties are identical, except for
+ <code>jar.resource.loader.path</code>, where you provide the full location of
+ the jar(s) you wish to load resources from.
+</li>
+<li>
+ <b>ClasspathResourceLoader :</b> This loader gets resources from the classloader.
While the
+ classpath is a source of great pain and suffering in general, it is a very useful
+ mechanism when working on a Servlet Spec 2.2 compliant servler runner.
+ <a href="http://jakarta.apache.org/tomcat/">Tomcat 3.2</a>
+ is an example of such. To use this loader effectively, all you must do is
+ jar your templates, and put that jar into the WEB-INF/lib directory of your
+ webapp. There are no configuration options to worry about, nor is the absolute
vs.
+ relative path an issue, as it is with Jar and File resource loaders.
+</li>
+
+<li>
+ <b>DataSourceResourceLoader :</b> This loader will load resources from a
DataSource
+such as a database. This loader is not built as part of the standard build
+as it requires J2EE support. To build this loader, please download the J2EE
+distribution, move the j2ee.jar into the <code>build/lib</code> directory,
+and then build the new velocity jar with the <code>jar-j2ee</code> build target.
+For more information on this loader, please see the javadoc for the class
+<code>org.apache.velocity.runtime.resource.loader.DataSourceResourceLoader</code>.
+</li>
+
+</ul>
+</p>
+ <strong>Configuration
Examples</strong>
+ <a name="resourceexamples" />
+ <p>
+Configuring the resource loaders for Velocity is straightforward.
+The properties that control the are listed in the
+<a href="developer-guide.html#config">resource configuration</a>
+section, for further reference.
+</p>
+ <p>
+The first step in configuring one or more resource loaders is do
+'declare' them by name to Velocity. Use the property
+<code>resource.loader</code> and list one or more loader names.
+You can use anything you want - these names are used to associate
+configuration properties with a given loader.
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+
+ resource.loader = file
+
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ <p>
+That entry declares that we will have a resource loader known as 'file'.
+The next thing to do is to set the important properties. The most critical
+is to declare the class to use as the loader :
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+
+ file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ <p>
+In this case, we are telling velocity that we are setting up
+a resource loadercalled 'file', and are using the class
+<code>
+org.apache.velocity.runtime.resource.loader.FileResourceLoader
+</code>
+to be the class to use.
+The next thing we do is set the properties important
+to this loader.
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+file.resource.loader.path = /opt/templates
+file.resource.loader.cache = true
+file.resource.loader.modificationCheckInterval = 2
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ <p>
+Here, we set a few things. First, we set the path to find
+the templates to be <code>/opt/templates</code>. Second, we
+turned caching on, so that after a template or static file
+is read in, it is cached in memory. And finally, we set
+the modification check interval to 2 seconds, allowing Velocity
+to check for new templates.
+</p>
+ <p>
+Those are the basics. What follows are a few examples of different configuraitons.
+</p>
+ <p>
+<b>Do-nothing Default Configuration : </b> As the name says, there is nothing
+you have to do or configure to get the default configuration. This configuration
+uses the FileResourceLoader with the current directory as the default resource
+path, and caching is off. As a properties set, this is expressed as :
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+resource.loader = file
+
+file.resource.loader.description = Velocity File Resource Loader
+file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+file.resource.loader.path = .
+file.resource.loader.cache = false
+file.resource.loader.modificationCheckInterval = 0
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ <p>
+<b>Multiple Template Path Configuration : </b> This configuration
+uses the FileResourceLoader with several directories as 'nodes' on the
+template search path. We also want to use caching, and have the templates
+checked for changes in 10 second intervals. As a properties set, this is expressed
as :
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+resource.loader = file
+
+file.resource.loader.description = Velocity File Resource Loader
+file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+file.resource.loader.path = /opt/directory1, /opt/directory2
+file.resource.loader.cache = true
+file.resource.loader.modificationCheckInterval = 10
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ <p>
+<b>Dual Loader Configuration :</b> This configuration sets up
+two loaders at the same time, the FileResourceLoaderm, and
+the ClasspathResourceLoader. The loaders are set-up such that the
+FileResourceLoader is consulted first, and then the
+ClasspathResourceLoader. This would allow you to qickly
+drop a template into the file template are to replace on of the
+templates found in the classpath (usually via a jar) without
+having to rebuild the jar.
+</p>
+ <div align="left">
+ <table cellspacing="4" cellpadding="0" border="0">
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#ffffff"><pre>
+resource.loader = file, class
+
+file.resource.loader.description = Velocity File Resource Loader
+file.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader
+file.resource.loader.path = .
+file.resource.loader.cache = false
+file.resource.loader.modificationCheckInterval = 0
+
+class.resource.loader.description = Velocity Classpath Resource Loader
+class.resource.loader.class =
org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader
+</pre></td>
+ <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ <tr>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
+ <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+ </tr>
+ </table>
+ </div>
+ <p>
+Note that the ClasspathResourceLoader doesn't require much configuration.
</p>
</blockquote>
</td></tr>
