SimpleTimeStampedTableParser.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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.hipparchus.exception.DummyLocalizable;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
import org.orekit.time.TimeStamped;
/**
* Parser for simple tables containing {@link TimeStamped time stamped} data.
* @param <T> the type of time stamped data (i.e. parsed table rows)
* @author Luc Maisonobe
* @since 6.1
*/
public class SimpleTimeStampedTableParser<T extends TimeStamped> {
/** Interface for converting a table row into time-stamped data.
* @param <S> the type of time stamped data (i.e. parsed table rows)
*/
public interface RowConverter<S extends TimeStamped> {
/** Convert a row.
* @param rawFields raw row fields, as read from the file
* @return converted row
*/
S convert(double[] rawFields);
}
/** Pattern for fields with real type. */
private static final String REAL_TYPE_PATTERN =
"[-+]?(?:(?:\\p{Digit}+(?:\\.\\p{Digit}*)?)|(?:\\.\\p{Digit}+))(?:[eE][-+]?\\p{Digit}+)?";
/** Number of columns. */
private final int columns;
/** Converter for rows. */
private final RowConverter<T> converter;
/** Simple constructor.
* @param columns number of columns
* @param converter converter for rows
*/
public SimpleTimeStampedTableParser(final int columns, final RowConverter<T> converter) {
this.columns = columns;
this.converter = converter;
}
/** Parse a stream.
* @param stream stream containing the table
* @param name name of the resource file (for error messages only)
* @return parsed table
*/
public List<T> parse(final InputStream stream, final String name) {
if (stream == null) {
throw new OrekitException(OrekitMessages.UNABLE_TO_FIND_FILE, name);
}
// regular lines are simply a space separated list of numbers
final StringBuilder builder = new StringBuilder("^\\p{Space}*");
for (int i = 0; i < columns; ++i) {
builder.append("(");
builder.append(REAL_TYPE_PATTERN);
builder.append(")");
builder.append((i < columns - 1) ? "\\p{Space}+" : "\\p{Space}*$");
}
final Pattern regularLinePattern = Pattern.compile(builder.toString());
// setup the reader
try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))) {
final List<T> table = new ArrayList<T>();
for (String line = reader.readLine(); line != null; line = reader.readLine()) {
// replace unicode minus sign ('−') by regular hyphen ('-') for parsing
// such unicode characters occur in tables that are copy-pasted from PDF files
line = line.replace('\u2212', '-');
final Matcher regularMatcher = regularLinePattern.matcher(line);
if (regularMatcher.matches()) {
// we have found a regular data line
final double[] rawFields = new double[columns];
for (int i = 0; i < columns; ++i) {
rawFields[i] = Double.parseDouble(regularMatcher.group(i + 1));
}
table.add(converter.convert(rawFields));
}
}
if (table.isEmpty()) {
throw new OrekitException(OrekitMessages.NOT_A_SUPPORTED_IERS_DATA_FILE, name);
}
return table;
} catch (IOException ioe) {
throw new OrekitException(ioe, new DummyLocalizable(ioe.getMessage()));
}
}
}