/*
* 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.
*
*/
package org.apache.tomcat.util.file;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import org.apache.tomcat.util.res.StringManager;
/**
* This class is used to obtain {@link InputStream}s for configuration files
* from a given location String. This allows greater flexibility than these
* files having to be loaded directly from a file system.
*/
public class ConfigFileLoader {
private static final StringManager sm = StringManager.getManager(ConfigFileLoader.class
.getPackage().getName());
private static final File CATALINA_BASE_FILE;
private static final URI CATALINA_BASE_URI;
static {
String catalinaBase = System.getProperty("catalina.base");
if (catalinaBase != null) {
CATALINA_BASE_FILE = new File(catalinaBase);
CATALINA_BASE_URI = CATALINA_BASE_FILE.toURI();
} else {
CATALINA_BASE_FILE = null;
CATALINA_BASE_URI = null;
}
}
private ConfigFileLoader() {
// Utility class. Hide the default constructor.
}
/**
* Load the resource from the specified location.
*
* @param location The location for the resource of interest. The location
* may be a URL or a file path. Relative paths will be
* resolved against CATALINA_BASE.
*
* @return The InputStream for the given resource. The caller is responsible
* for closing this stream when it is no longer used.
*
* @throws IOException If an InputStream cannot be created using the
* provided location
*/
public static InputStream getInputStream(String location) throws IOException {
// Absolute URIs will be left alone
// Relative files will be resolved relative to catalina base
// Absolute files will be converted to URIs
// Location was originally always a file before URI support was added so
// try file first.
// First guess, an absolute file path
File file = new File(location);
if (!file.isAbsolute()) {
// Second guess, a file path relative to CATALINA_BASE
file = new File(CATALINA_BASE_FILE, location);
}
if (file.isFile()) {
return new FileInputStream(file);
}
// Third and final guess, a URI
URI uri;
if (CATALINA_BASE_URI != null) {
uri = CATALINA_BASE_URI.resolve(location);
} else {
uri = URI.create(location);
}
// Obtain the input stream we need
try {
return uri.toURL().openStream();
} catch (IllegalArgumentException e) {
throw new IOException(sm.getString("configFileLoader.cannotObtainURL", location), e);
}
}
}