/*
* Copyright (c) 2003 The Visigoth Software Society. 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 acknowledgement:
* "This product includes software developed by the
* Visigoth Software Society (http://www.visigoths.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
* project contributors may be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
* nor may "FreeMarker" or "Visigoth" appear in their names
* without prior written permission of the Visigoth Software Society.
*
* 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 VISIGOTH SOFTWARE SOCIETY 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 Visigoth Software Society. For more
* information on the Visigoth Software Society, please see
* http://www.visigoths.org/
*/
package freemarker.cache;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
/**
* This is an abstract template loader that can load templates whose
* location can be described by an URL. Subclasses only need to override
* the {@link #getURL(String)} method. Both {@link ClassTemplateLoader} and
* {@link WebappTemplateLoader} are (quite trivial) subclasses of this class.
* @version $Id: URLTemplateLoader.java,v 1.14 2003/01/29 08:01:17 szegedia Exp $
* @author Attila Szegedi
*/
public abstract class URLTemplateLoader implements TemplateLoader
{
public Object findTemplateSource(String name)
throws
IOException
{
URL url = getURL(name);
return url == null ? null : new URLTemplateSource(url);
}
/**
* Given a template name (plus potential locale decorations) retrieves
* an URL that points the template source.
* @param name the name of the sought template, including the locale
* decorations.
* @return an URL that points to the template source, or null if it can
* determine that the template source does not exist.
*/
protected abstract URL getURL(String name);
public long getLastModified(Object templateSource)
{
return ((URLTemplateSource) templateSource).lastModified();
}
public Reader getReader(Object templateSource, String encoding)
throws
IOException
{
return new InputStreamReader(
((URLTemplateSource) templateSource).getInputStream(),
encoding);
}
public void closeTemplateSource(Object templateSource)
throws
IOException
{
((URLTemplateSource) templateSource).close();
}
/**
* Can be used by subclasses to canonicalize URL path prefixes.
* @param prefix the path prefix to canonicalize
* @return the canonicalized prefix. All backslashes are replaced with
* forward slashes, and a trailing slash is appended if the original
* prefix wasn't empty and didn't already end with a slash.
*/
protected static String canonicalizePrefix(String prefix)
{
// make it foolproof
prefix = prefix.replace('\\', '/');
// ensure there's a trailing slash
if (prefix.length() > 0 && !prefix.endsWith("/"))
{
prefix += "/";
}
return prefix;
}
}
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