package bboss.org.apache.velocity.texen.util;
/*
* 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 java.io.FileInputStream;
import java.io.InputStream;
import java.util.Properties;
import java.util.StringTokenizer;
import bboss.org.apache.velocity.texen.Generator;
/**
* A property utility class for the texen text/code generator
* Usually this class is only used from a Velocity context.
*
* @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
* @author <a href="mailto:sbailliez@apache.org">Stephane Bailliez</a>
* @version $Id: PropertiesUtil.java 510628 2007-02-22 19:07:59Z nbubna $
*/
public class PropertiesUtil
{
/**
* Load properties from either a file in the templatePath if there
* is one or the classPath.
*
* @param propertiesFile the properties file to load through
* either the templatePath or the classpath.
* @return a properties instance filled with the properties found
* in the file or an empty instance if no file was found.
*/
public Properties load(final String propertiesFile)
{
Properties properties = null;
String templatePath = Generator.getInstance().getTemplatePath();
try
{
if (templatePath != null)
{
properties = loadFromTemplatePath(propertiesFile);
}
else
{
properties = loadFromClassPath(propertiesFile);
}
}
catch (RuntimeException e)
{
throw e;
}
catch (Exception e)
{
throw new RuntimeException("Could not load properties: " + e.getMessage());
}
return properties;
}
/**
* Load a properties file from the templatePath defined in the
* generator. As the templatePath can contains multiple paths,
* it will cycle through them to find the file. The first file
* that can be successfully loaded is considered. (kind of
* like the java classpath), it is done to clone the Velocity
* process of loading templates.
*
* @param propertiesFile the properties file to load. It must be
* a relative pathname.
* @return a properties instance loaded with the properties from
* the file. If no file can be found it returns an empty instance.
* @throws Exception
*/
protected Properties loadFromTemplatePath(final String propertiesFile)
throws Exception
{
Properties properties = new Properties();
String templatePath = Generator.getInstance().getTemplatePath();
// We might have something like the following:
//
// #set ($dbprops = $properties.load("$generator.templatePath/path/props")
//
// as we have in Torque but we want people to start using
//
// #set ($dbprops = $properties.load("path/props")
//
// so that everything works from the filesystem or from
// a JAR. So the actual Generator.getTemplatePath()
// is not deprecated but it's use in templates
// should be.
StringTokenizer st = new StringTokenizer(templatePath, ",");
while (st.hasMoreTokens())
{
String templateDir = st.nextToken();
InputStream stream = null;
try
{
// If the properties file is being pulled from the
// file system and someone is using the method whereby
// the properties file is assumed to be in the template
// path and they are simply using:
//
// #set ($dbprops = $properties.load("props") (1)
//
// than we have to tack on the templatePath in order
// for the properties file to be found. We want (1)
// to work whether the generation is being run from
// the file system or from a JAR file.
String fullPath = propertiesFile;
// FIXME probably not that clever since there could be
// a mix of file separators and the test will fail :-(
if (!fullPath.startsWith(templateDir))
{
fullPath = templateDir + "/" + propertiesFile;
}
stream = new FileInputStream(fullPath);
properties.load(stream);
// first pick wins, we don't need to go further since
// we found a valid file.
break;
}
finally
{
if (stream != null)
{
stream.close();
}
}
}
return properties;
}
/**
* Load a properties file from the classpath
*
* @param propertiesName the properties file to load.
* @return a properties instance loaded with the properties from
* the file. If no file can be found it returns an empty instance.
* @throws Exception
*/
protected Properties loadFromClassPath(final String propertiesName)
throws Exception
{
Properties properties = new Properties();
ClassLoader classLoader = this.getClass().getClassLoader();
InputStream inputStream = null;
try
{
// This is a hack for now to make sure that properties
// files referenced in the filesystem work in
// a JAR file. We have to deprecate the use
// of $generator.templatePath in templates first
// and this hack will allow those same templates
// that use $generator.templatePath to work in
// JAR files.
String propertiesFile = propertiesName.startsWith("$generator")
? propertiesName.substring("$generator.templatePath/".length())
: propertiesName;
inputStream = classLoader.getResourceAsStream(propertiesFile);
properties.load(inputStream);
}
finally
{
if (inputStream != null)
{
inputStream.close();
}
}
return properties;
}
}