Java tutorial
/* ************************************************************************ ******************* CANADIAN ASTRONOMY DATA CENTRE ******************* ************** CENTRE CANADIEN DE DONNES ASTRONOMIQUES ************** * * (c) 2018. (c) 2018. * Government of Canada Gouvernement du Canada * National Research Council Conseil national de recherches * Ottawa, Canada, K1A 0R6 Ottawa, Canada, K1A 0R6 * All rights reserved Tous droits rservs * * NRC disclaims any warranties, Le CNRC dnie toute garantie * expressed, implied, or nonce, implicite ou lgale, * statutory, of any kind with de quelque nature que ce * respect to the software, soit, concernant le logiciel, * including without limitation y compris sans restriction * any warranty of merchantability toute garantie de valeur * or fitness for a particular marchande ou de pertinence * purpose. NRC shall not be pour un usage particulier. * liable in any event for any Le CNRC ne pourra en aucun cas * damages, whether direct or tre tenu responsable de tout * indirect, special or general, dommage, direct ou indirect, * consequential or incidental, particulier ou gnral, * arising from the use of the accessoire ou fortuit, rsultant * software. Neither the name de l'utilisation du logiciel. Ni * of the National Research le nom du Conseil National de * Council of Canada nor the Recherches du Canada ni les noms * names of its contributors may de ses participants ne peuvent * be used to endorse or promote tre utiliss pour approuver ou * products derived from this promouvoir les produits drivs * software without specific prior de ce logiciel sans autorisation * written permission. pralable et particulire * par crit. * * This file is part of the Ce fichier fait partie du projet * OpenCADC project. OpenCADC. * * OpenCADC is free software: OpenCADC est un logiciel libre ; * you can redistribute it and/or vous pouvez le redistribuer ou le * modify it under the terms of modifier suivant les termes de * the GNU Affero General Public la GNU Affero General Public * License as published by the License? telle que publie * Free Software Foundation, par la Free Software Foundation * either version 3 of the : soit la version 3 de cette * License, or (at your option) licence, soit ( votre gr) * any later version. toute version ultrieure. * * OpenCADC is distributed in the OpenCADC est distribu * hope that it will be useful, dans lespoir quil vous * but WITHOUT ANY WARRANTY; sera utile, mais SANS AUCUNE * without even the implied GARANTIE : sans mme la garantie * warranty of MERCHANTABILITY implicite de COMMERCIALISABILIT * or FITNESS FOR A PARTICULAR ni dADQUATION UN OBJECTIF * PURPOSE. See the GNU Affero PARTICULIER. Consultez la Licence * General Public License for Gnrale Publique GNU Affero * more details. pour plus de dtails. * * You should have received Vous devriez avoir reu une * a copy of the GNU Affero copie de la Licence Gnrale * General Public License along Publique GNU Affero avec * with OpenCADC. If not, see OpenCADC ; si ce nest * <http://www.gnu.org/licenses/>. pas le cas, consultez : * <http://www.gnu.org/licenses/>. * ************************************************************************ */ package ca.nrc.cadc.tap.db; import ca.nrc.cadc.dali.tables.votable.VOTableField; import ca.nrc.cadc.dali.util.Format; import ca.nrc.cadc.dali.util.FormatFactory; import ca.nrc.cadc.tap.schema.ColumnDesc; import ca.nrc.cadc.tap.schema.TableDesc; import ca.nrc.cadc.tap.schema.TapSchemaUtil; import ca.nrc.cadc.vosi.actions.TableContentHandler; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import org.apache.commons.csv.CSVFormat; import org.apache.commons.csv.CSVParser; import org.apache.commons.csv.CSVRecord; import org.apache.log4j.Logger; /** * Class to produce formatted row and column data through an iterator. * * @author majorb * */ public class AsciiTableData implements TableDataInputStream, Iterator<List<Object>> { private static final Logger log = Logger.getLogger(AsciiTableData.class); private final CSVParser reader; private final Iterator<CSVRecord> rowIterator; private List<String> columnNames; private List<Format> columnFormats; /** * Constructor. * * @param in The data stream * @param contentType The content type of the data * @throws IOException If a data handling error occurs */ public AsciiTableData(InputStream in, String contentType) throws IOException { char delimiter = ','; if (contentType.equals(TableContentHandler.CONTENT_TYPE_TSV)) { delimiter = '\t'; } InputStreamReader ir = new InputStreamReader(in); if (TableContentHandler.CONTENT_TYPE_TSV.equals(contentType)) { this.reader = new CSVParser(ir, CSVFormat.TDF.withFirstRecordAsHeader()); } else if (TableContentHandler.CONTENT_TYPE_CSV.equals(contentType)) { this.reader = new CSVParser(ir, CSVFormat.DEFAULT.withFirstRecordAsHeader()); } else { throw new UnsupportedOperationException("contentType: " + contentType); } this.rowIterator = reader.iterator(); Map<String, Integer> header = reader.getHeaderMap(); columnNames = new ArrayList<String>(header.size()); for (String s : header.keySet()) { columnNames.add(s.trim()); log.debug("found column: " + s); } if (columnNames.isEmpty()) { throw new IllegalArgumentException("No data columns."); } } public void close() { if (reader != null) { try { reader.close(); } catch (IOException ex) { log.debug("failed to close CSVParser", ex); } } } /** * Return the data iterator. * @return */ @Override public Iterator<List<Object>> iterator() { return this; } /** * @return True if the data stream has more rows. */ @Override public boolean hasNext() { return rowIterator.hasNext(); } /** * @return The list of formatted objects representing a row of data. */ @Override public List<Object> next() { if (!hasNext()) { throw new IllegalStateException("No more data to read."); } CSVRecord rec = rowIterator.next(); if (rec.size() != columnNames.size()) { throw new IllegalArgumentException( "wrong number of columns (" + rec.size() + ") expected " + columnNames.size()); } try { List<Object> row = new ArrayList<Object>(columnNames.size()); String cell = null; Object value = null; Format format = null; for (int i = 0; i < rec.size(); i++) { cell = rec.get(i); format = columnFormats.get(i); value = format.parse(cell); row.add(value); } return row; } catch (NumberFormatException ex) { throw new IllegalArgumentException("invalid number: " + ex.getMessage()); } } @Override public void remove() { throw new UnsupportedOperationException(); } @Override public TableDesc acceptTargetTableDesc(TableDesc target) { TableDesc td = new TableDesc(target.getSchemaName(), target.getTableName()); ColumnDesc colDesc = null; for (String col : columnNames) { colDesc = target.getColumn(col); if (colDesc == null) { throw new IllegalArgumentException("Unrecognized column name: " + col); } td.getColumnDescs().add(colDesc); } createColumnFormats(td); return td; } private void createColumnFormats(TableDesc tableDesc) { FormatFactory formatFactory = new FormatFactory(); this.columnFormats = new ArrayList<Format>(columnNames.size()); for (String col : columnNames) { ColumnDesc colDesc = tableDesc.getColumn(col); VOTableField voTableField = TapSchemaUtil.convert(colDesc); Format format = formatFactory.getFormat(voTableField); columnFormats.add(format); } } }