AbstractListCrawler.java
/* Copyright 2002-2022 CS GROUP
* Licensed to CS GROUP (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.text.ParseException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import org.hipparchus.exception.DummyLocalizable;
import org.orekit.errors.OrekitException;
/** Provider for data files defined in a list.
* <p>
* All {@link FiltersManager#addFilter(DataFilter) registered}
* {@link DataFilter filters} are applied.
* </p>
* <p>
* Zip archives entries are supported recursively.
* </p>
* @since 10.1
* @see DataProvidersManager
* @see NetworkCrawler
* @see FilesListCrawler
* @author Luc Maisonobe
* @param <T> The type of resource, e.g. File or URL.
*/
public abstract class AbstractListCrawler<T> implements DataProvider {
/** Inputs list. */
private final List<T> inputs;
/** Build a data classpath crawler.
* @param inputs list of inputs (may be empty if {@link #addInput(Object) addInput} is called later)
*/
@SafeVarargs
protected AbstractListCrawler(final T... inputs) {
this.inputs = Arrays.stream(inputs).collect(Collectors.toList());
}
/** Add an input to the supported list.
* @param input input to add
*/
public void addInput(final T input) {
inputs.add(input);
}
/** Get the list of inputs supported by the instance.
* @return unmodifiable view of the list of inputs supported by the instance
*/
public List<T> getInputs() {
return Collections.unmodifiableList(inputs);
}
/** Get the complete name of a input.
* @param input input to consider
* @return complete name of the input
*/
protected abstract String getCompleteName(T input);
/** Get the base name of an input.
* @param input input to consider
* @return base name of the input
*/
protected abstract String getBaseName(T input);
/** Get a zip/jar crawler for an input.
* @param input input to consider
* @return zip/jar crawler for an input
*/
protected abstract ZipJarCrawler getZipJarCrawler(T input);
/** Get the stream to read from an input.
* @param input input to read from
* @return stream to read the content of the input
* @throws IOException if the input cannot be opened for reading
*/
protected abstract InputStream getStream(T input) throws IOException;
/** {@inheritDoc} */
@Override
public boolean feed(final Pattern supported,
final DataLoader visitor,
final DataProvidersManager manager) {
try {
OrekitException delayedException = null;
boolean loaded = false;
for (T input : inputs) {
try {
if (visitor.stillAcceptsData()) {
final String name = getCompleteName(input);
final String fileName = getBaseName(input);
if (ZIP_ARCHIVE_PATTERN.matcher(fileName).matches()) {
// browse inside the zip/jar file
getZipJarCrawler(input).feed(supported, visitor, manager);
loaded = true;
} else {
// apply all registered filters
DataSource data = new DataSource(fileName, () -> getStream(input));
data = manager.getFiltersManager().applyRelevantFilters(data);
if (supported.matcher(data.getName()).matches()) {
// visit the current file
try (InputStream is = data.getOpener().openStreamOnce()) {
visitor.loadData(is, name);
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;
}
}
if (!loaded && delayedException != null) {
throw delayedException;
}
return loaded;
} catch (IOException | ParseException e) {
throw new OrekitException(e, new DummyLocalizable(e.getMessage()));
}
}
}