package org.apache.fulcrum.yaafi.framework.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.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.avalon.framework.logger.Logger;
import org.apache.avalon.framework.logger.NullLogger;
/**
* Helper for locating a file name and returning an input stream.
*
* @author <a href="mailto:siegfried.goeschl@it20one.at">Siegfried Goeschl</a>
*/
public class InputStreamLocator
{
/** the root directory of our search */
private File rootDir;
/** the logger to be used */
private Logger logger;
/**
* Constructor
*/
public InputStreamLocator()
{
this.rootDir = new File( new File("").getAbsolutePath() );
this.logger = new NullLogger();
}
/**
* Constructor
*
* @param rootDir the root directory to start the search */
public InputStreamLocator( File rootDir )
{
this( rootDir, new NullLogger() );
}
/**
* Constructor
*
* @param rootDir the root directory to start the search
* @param logger the logger to be used
*/
public InputStreamLocator( File rootDir, Logger logger )
{
this.rootDir = rootDir;
this.logger = logger;
}
/**
* Locate the file with the given position using the following steps
*
* @param location the location of the source to be loaded
*/
public InputStream locate( String location ) throws IOException
{
if( ( location == null ) || ( location.length() == 0 ) )
{
return null;
}
String baseName = null;
File file = null;
InputStream is = null;
// try to load a relative location with the given root dir
// e.g. "componentRoles.xml" located in the current working directory
if( is == null )
{
file = new File( this.rootDir, location );
this.getLogger().debug("Looking for " + location + " in the root directory");
if( file.exists() )
{
is = new FileInputStream( file );
this.getLogger().debug("Found " + location + " as " + file.getAbsolutePath() );
}
}
// try to load an absolute location as file
// e.g. "/foo/componentRoles.xml" from the root of the file system
if( is == null )
{
file = new File( location );
this.getLogger().debug("Looking for " + location + " as absolute file location");
if( file.isAbsolute() && file.exists() )
{
is = new FileInputStream( file );
this.getLogger().debug("Found " + location + " as " + file.getAbsolutePath() );
}
}
// try to load an absolute location through the classpath
// e.g. "/componentRoles.xml" located in the classpath
if( ( is == null ) && ( location.startsWith( "/" ) == true ) )
{
this.getLogger().debug("Looking for " + location + " using the class loader");
is = getClass().getResourceAsStream( location );
}
if( is == null )
{
this.getLogger().warn("Unable to locate " + location);
}
else
{
this.getLogger().debug("Successfully located " + location);
}
// try to load the last part of the file name using the classloader
// e.g. "conf/componentRoles.xml" as "/componentRoles.xml" located in
// the classpath.
if( ( is == null ) && ( location.startsWith( "/" ) == false ) )
{
baseName = '/' + new File(location).getName();
this.getLogger().debug("Looking for " + baseName + " using the class loader");
is = getClass().getResourceAsStream( baseName );
}
if( is == null )
{
this.getLogger().warn("Unable to locate " + baseName);
}
else
{
this.getLogger().debug("Successfully located " + baseName);
}
return is;
}
/**
* @return Returns the logger.
*/
protected Logger getLogger()
{
return logger;
}
/**
* @return Returns the rootDir.
*/
protected File getRootDir()
{
return rootDir;
}
}