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Posted to dev@velocity.apache.org by ge...@apache.org on 2001/03/05 03:59:29 UTC
cvs commit: jakarta-velocity/src/java/org/apache/velocity/runtime/resource/loader ClasspathResourceLoader.java
geirm 01/03/04 18:59:29
Added: src/java/org/apache/velocity/runtime/resource/loader
ClasspathResourceLoader.java
Log:
Simple loader to get templates from the resources in the classpath.
Exceptionally useful, I think, for servlet use on a v2.2 or better
servlet container - you just jar up your templates any way you want
and drop them into WEB-INF/lib, and that's it. No configuration
files to worry about, nor do you have to manually set the root of
your template paths at runtime, so you webapp is easily portable
w/o extra work.
Tested with Tomcat 3.2.1 - should be fine with Catalina as well.
Also tested with jars explicitly placed in the classpath (yech) as well
as simply adding the template-containing directory to the classpath
(yech also).
But it works.
Revision Changes Path
1.1 jakarta-velocity/src/java/org/apache/velocity/runtime/resource/loader/ClasspathResourceLoader.java
Index: ClasspathResourceLoader.java
===================================================================
package org.apache.velocity.runtime.resource.loader;
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.io.InputStream;
import org.apache.velocity.runtime.Runtime;
import org.apache.velocity.runtime.resource.Resource;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.configuration.Configuration;
/**
* ClasspathResourceLoader is a simple loader that will load
* templates from the classpath.
* <br>
* <br>
* Will load templates from from multiple instances of
* and arbitrary combinations of :
* <ul>
* <li> jar files
* <li> zip files
* <li> template directories (any directory containing templates)
* </ul>
* This is a configuration-free loader, in that there are no
* parameters to be specified in the configuration properties,
* other than specifying this as the loader to use. For example
* the following is all that the loader needs to be functional :
* <br>
* <br>
* resource.loader.1.class =
* org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader
* <br>
* <br>
* To use, put your template directories, jars
* and zip files into the classpath or other mechanisms that make
* resources accessable to the classloader.
* <br>
* <br>
* This makes deployment trivial for web applications running in
* any Servlet 2.2 compliant servlet runner, such as Tomcat 3.2
* and others.
* <br>
* <br>
* For a Servlet Spec v2.2 servlet runner,
* just drop the jars of template files into the WEB-INF/lib
* directory of your webapp, and you won't have to worry about setting
* template paths or altering them with the root of the webapp
* before initializing.
* <br>
* <br>
* I have also tried it with a WAR deployment, and that seemed to
* work just fine.
*
* @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
* @version $Id: ClasspathResourceLoader.java,v 1.1 2001/03/05 02:59:28 geirm Exp $
*/
public class ClasspathResourceLoader extends ResourceLoader
{
/**
* This is abstract in the base class, so we need it
*/
public void init(Configuration configuration)
{
}
/**
* Get an InputStream so that the Runtime can build a
* template with it.
*
* @param name name of template to get
* @return InputStream containing the template
* @throws ResourceNotFoundException if template not found
* in classpath.
*/
public synchronized InputStream getResourceStream( String name )
throws ResourceNotFoundException
{
InputStream result = null;
if (name == null || name.length() == 0)
{
throw new ResourceNotFoundException ("No template name provided");
}
try
{
ClassLoader classLoader = this.getClass().getClassLoader();
result= classLoader.getResourceAsStream( name );
}
catch( Exception fnfe )
{
/*
* log and convert to a general Velocity ResourceNotFoundException
*/
Runtime.error("ClasspathResourceLoader Error : exception : " + fnfe );
throw new ResourceNotFoundException( fnfe.getMessage() );
}
return result;
}
public boolean isSourceModified(Resource resource)
{
return false;
}
public long getLastModified(Resource resource)
{
return 0;
}
}