/* Copyright 2002-2017 CS Systèmes d'Information
* Licensed to CS Systèmes d'Information (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS 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.orekit.data;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.GZIPInputStream;
import org.hipparchus.exception.DummyLocalizable;
import org.hipparchus.exception.LocalizedCoreFormats;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
/** Provider for data files stored as resources in the classpath.
* <p>
* This class handles a list of data files or zip/jar archives located in the
* classpath. Since the classpath is not a tree structure the list elements
* cannot be whole directories recursively browsed as in {@link
* DirectoryCrawler}, they must be data files or zip/jar archives.
* </p>
* <p>
* A typical use case is to put all data files in a single zip or jar archive
* and to build an instance of this class with the single name of this zip/jar
* archive. Two different instances may be used one for user or project specific
* data and another one for system-wide or general data.
* </p>
* <p>
* Gzip-compressed files are supported.
* </p>
* <p>
* Zip archives entries are supported recursively.
* </p>
* <p>
* This is a simple application of the <code>visitor</code> design pattern for
* list browsing.
* </p>
* @see DataProvidersManager
* @author Luc Maisonobe
*/
public class ClasspathCrawler implements DataProvider {
/** List elements. */
private final List<String> listElements;
/** Class loader to use. */
private final ClassLoader classLoader;
/** Build a data classpath crawler.
* <p>
* Calling this constructor has the same effect as calling
* {@link #ClasspathCrawler(ClassLoader, String...)} with
* {@code ClasspathCrawler.class.getClassLoader()} as first
* argument.
* </p>
* @param list list of data file names within the classpath
* @exception OrekitException if a list elements is not an existing resource
*/
public ClasspathCrawler(final String... list) throws OrekitException {
this(ClasspathCrawler.class.getClassLoader(), list);
}
/** Build a data classpath crawler.
* @param classLoader class loader to use to retrieve the resources
* @param list list of data file names within the classpath
* @exception OrekitException if a list elements is not an existing resource
*/
public ClasspathCrawler(final ClassLoader classLoader, final String... list)
throws OrekitException {
listElements = new ArrayList<String>();
this.classLoader = classLoader;
// check the resources
for (final String name : list) {
if (!"".equals(name)) {
final String convertedName = name.replace('\\', '/');
final InputStream stream = classLoader.getResourceAsStream(convertedName);
if (stream == null) {
throw new OrekitException(OrekitMessages.UNABLE_TO_FIND_RESOURCE, name);
}
listElements.add(convertedName);
try {
stream.close();
} catch (IOException exc) {
// ignore this error
}
}
}
}
/** {@inheritDoc} */
public boolean feed(final Pattern supported, final DataLoader visitor)
throws OrekitException {
try {
OrekitException delayedException = null;
boolean loaded = false;
for (final String name : listElements) {
try {
if (visitor.stillAcceptsData()) {
if (ZIP_ARCHIVE_PATTERN.matcher(name).matches()) {
// browse inside the zip/jar file
final DataProvider zipProvider = new ZipJarCrawler(name);
loaded = zipProvider.feed(supported, visitor) || loaded;
} else {
// remove suffix from gzip files
final Matcher gzipMatcher = GZIP_FILE_PATTERN.matcher(name);
final String baseName = gzipMatcher.matches() ? gzipMatcher.group(1) : name;
if (supported.matcher(baseName).matches()) {
final InputStream stream = classLoader.getResourceAsStream(name);
final URI uri = classLoader.getResource(name).toURI();
// visit the current file
if (gzipMatcher.matches()) {
visitor.loadData(new GZIPInputStream(stream), uri.toString());
} else {
visitor.loadData(stream, uri.toString());
}
stream.close();
loaded = true;
}
}
}
} catch (OrekitException oe) {
// maybe the next path component will be able to provide data
// wait until all components have been tried
delayedException = oe;
} catch (URISyntaxException use) {
// this should bever happen
throw new OrekitException(use, LocalizedCoreFormats.SIMPLE_MESSAGE, use.getMessage());
}
}
if (!loaded && delayedException != null) {
throw delayedException;
}
return loaded;
} catch (IOException ioe) {
throw new OrekitException(ioe, new DummyLocalizable(ioe.getMessage()));
} catch (ParseException pe) {
throw new OrekitException(pe, new DummyLocalizable(pe.getMessage()));
}
}
}