/*
* Copyright 2002-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.ui.freemarker;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import freemarker.cache.TemplateLoader;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
/**
* FreeMarker TemplateLoader adapter that loads via a Spring ResourceLoader.
* Used by FreeMarkerConfigurationFactory for any resource loader path that
* cannot be resolved to a java.io.File.
*
* @author Juergen Hoeller
* @since 14.03.2004
* @see FreeMarkerConfigurationFactory#setTemplateLoaderPath
* @see freemarker.template.Configuration#setDirectoryForTemplateLoading
*/
public class SpringTemplateLoader implements TemplateLoader {
protected final Log logger = LogFactory.getLog(getClass());
private final ResourceLoader resourceLoader;
private final String templateLoaderPath;
/**
* Create a new SpringTemplateLoader.
* @param resourceLoader the Spring ResourceLoader to use
* @param templateLoaderPath the template loader path to use
*/
public SpringTemplateLoader(ResourceLoader resourceLoader, String templateLoaderPath) {
this.resourceLoader = resourceLoader;
if (!templateLoaderPath.endsWith("/")) {
templateLoaderPath += "/";
}
this.templateLoaderPath = templateLoaderPath;
if (logger.isInfoEnabled()) {
logger.info("SpringTemplateLoader for FreeMarker: using resource loader [" + this.resourceLoader +
"] and template loader path [" + this.templateLoaderPath + "]");
}
}
public Object findTemplateSource(String name) throws IOException {
if (logger.isDebugEnabled()) {
logger.debug("Looking for FreeMarker template with name [" + name + "]");
}
Resource resource = this.resourceLoader.getResource(this.templateLoaderPath + name);
return (resource.exists() ? resource : null);
}
public Reader getReader(Object templateSource, String encoding) throws IOException {
Resource resource = (Resource) templateSource;
try {
return new InputStreamReader(resource.getInputStream(), encoding);
}
catch (IOException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not find FreeMarker template: " + resource);
}
throw ex;
}
}
public long getLastModified(Object templateSource) {
Resource resource = (Resource) templateSource;
try {
return resource.lastModified();
}
catch (IOException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not obtain last-modified timestamp for FreeMarker template in " +
resource + ": " + ex);
}
return -1;
}
}
public void closeTemplateSource(Object templateSource) throws IOException {
}
}