org.apache.velocity.runtime.resource.loader.JarResourceLoader Maven / Gradle / Ivy
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package org.apache.velocity.runtime.resource.loader;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.resource.Resource;
import org.apache.velocity.util.ExtProperties;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.lang3.StringUtils;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.HashMap;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
/**
*
* ResourceLoader to load templates from multiple Jar files.
*
*
* The configuration of the JarResourceLoader is straightforward -
* You simply add the JarResourceLoader to the configuration via
*
*
* resource.loaders = jar
* resource.loader.jar.class = org.apache.velocity.runtime.resource.loader.JarResourceLoader
* resource.loader.jar.path = list of JAR <URL>s
*
*
* So for example, if you had a jar file on your local filesystem, you could simply do
*
* resource.loader.jar.path = jar:file:/opt/myfiles/jar1.jar
*
* Note that jar specification for the .path configuration property
* conforms to the same rules for the java.net.JarUrlConnection class.
*
*
* For a working example, see the unit test case,
* org.apache.velocity.test.MultiLoaderTestCase class
*
*
* @author Aki Nieminen
* @author Dave Bryson
* @version $Id$
*/
public class JarResourceLoader extends ResourceLoader
{
/**
* Maps entries to the parent JAR File
* Key = the entry *excluding* plain directories
* Value = the JAR URL
*/
private Map entryDirectory = new HashMap<>(559);
/**
* Maps JAR URLs to the actual JAR
* Key = the JAR URL
* Value = the JAR
*/
private Map jarfiles = new HashMap<>(89);
/**
* Called by Velocity to initialize the loader
* @param configuration
*/
@Override
public void init(ExtProperties configuration)
{
log.trace("JarResourceLoader: initialization starting.");
List paths = configuration.getList(RuntimeConstants.RESOURCE_LOADER_PATHS);
if (paths != null)
{
log.debug("JarResourceLoader # of paths: {}", paths.size() );
for (ListIterator it = paths.listIterator(); it.hasNext(); )
{
String jar = StringUtils.trim(it.next());
it.set(jar);
loadJar(jar);
}
}
log.trace("JarResourceLoader: initialization complete.");
}
private void loadJar( String path )
{
log.debug("JarResourceLoader: trying to load \"{}\"", path);
// Check path information
if ( path == null )
{
String msg = "JarResourceLoader: can not load JAR - JAR path is null";
log.error(msg);
throw new RuntimeException(msg);
}
if ( !path.startsWith("jar:") )
{
String msg = "JarResourceLoader: JAR path must start with jar: -> see java.net.JarURLConnection for information";
log.error(msg);
throw new RuntimeException(msg);
}
if (!path.contains("!/"))
{
path += "!/";
}
// Close the jar if it's already open
// this is useful for a reload
closeJar( path );
// Create a new JarHolder
JarHolder temp = new JarHolder( rsvc, path, log );
// Add it's entries to the entryCollection
addEntries(temp.getEntries());
// Add it to the Jar table
jarfiles.put(temp.getUrlPath(), temp);
}
/**
* Closes a Jar file and set its URLConnection
* to null.
*/
private void closeJar( String path )
{
if ( jarfiles.containsKey(path) )
{
JarHolder theJar = jarfiles.get(path);
theJar.close();
}
}
/**
* Copy all the entries into the entryDirectory
* It will overwrite any duplicate keys.
*/
private void addEntries( Map entries )
{
entryDirectory.putAll( entries );
}
/**
* Get a Reader so that the Runtime can build a
* template with it.
*
* @param source name of template to get
* @param encoding asked encoding
* @return InputStream containing the template
* @throws ResourceNotFoundException if template not found
* in the file template path.
* @since 2.0
*/
@Override
public Reader getResourceReader(String source, String encoding )
throws ResourceNotFoundException
{
Reader result = null;
if (org.apache.commons.lang3.StringUtils.isEmpty(source))
{
throw new ResourceNotFoundException("Need to have a resource!");
}
String normalizedPath = FilenameUtils.normalize( source, true );
if ( normalizedPath == null || normalizedPath.length() == 0 )
{
String msg = "JAR resource error: argument " + normalizedPath +
" contains .. and may be trying to access " +
"content outside of template root. Rejected.";
log.error( "JarResourceLoader: {}", msg );
throw new ResourceNotFoundException ( msg );
}
/*
* if a / leads off, then just nip that :)
*/
if ( normalizedPath.startsWith("/") )
{
normalizedPath = normalizedPath.substring(1);
}
if ( entryDirectory.containsKey( normalizedPath ) )
{
String jarurl = entryDirectory.get( normalizedPath );
if ( jarfiles.containsKey( jarurl ) )
{
JarHolder holder = (JarHolder)jarfiles.get( jarurl );
InputStream rawStream = holder.getResource( normalizedPath );
try
{
return buildReader(rawStream, encoding);
}
catch (Exception e)
{
if (rawStream != null)
{
try
{
rawStream.close();
}
catch (IOException ioe) {}
}
String msg = "JAR resource error: Exception while loading " + source;
log.error(msg, e);
throw new VelocityException(msg, e, rsvc.getLogContext().getStackTrace());
}
}
}
throw new ResourceNotFoundException( "JarResourceLoader Error: cannot find resource " +
source );
}
// TODO: SHOULD BE DELEGATED TO THE JARHOLDER
/**
* @see ResourceLoader#isSourceModified(org.apache.velocity.runtime.resource.Resource)
*/
@Override
public boolean isSourceModified(Resource resource)
{
return true;
}
/**
* @see ResourceLoader#getLastModified(org.apache.velocity.runtime.resource.Resource)
*/
@Override
public long getLastModified(Resource resource)
{
return 0;
}
}