001 package edu.nrao.sss.model.source.parser;
002
003 import java.io.IOException;
004 import java.io.LineNumberReader;
005 import java.io.Reader;
006
007 import edu.nrao.sss.model.source.SourceCatalog;
008
009 /**
010 * A parser of source catalog text files in the VLBA's format.
011 * Lines that start with "#" are comments. Data lines conform
012 * to this format:
013 * <pre>
014 * J2000 name IVS name Right ascension Declination Pos_err X-band flux S-band flux C-Cat
015 * Total Unres Total Unres
016 * hr mn seconds deg mn seconds mas Jy Jy Jy Jy
017 * </pre>
018 * Whitespace is used as the delimiter. This parser does not count columns in
019 * order to find the next field, it just uses the whitespace. This means you
020 * may put any number of spaces between data items. Here is an example from
021 * the VLBA catalog:
022 * <pre>
023 * J1254+4536 1252+458 12h54m28.828654s +45d36'04.32606" 1.02 0.12 0.10 0.21 0.20 C-VCS1
024 * </pre>
025 * For more detailed information about this format, see the
026 * <a href="http://www.vlba.nrao.edu/astro/calib/vlbaCalib.txt">
027 * VLBA Calibrator List</a>.
028 * <p>
029 * <b>Version Info:</b>
030 * <table style="margin-left:2em">
031 * <tr><td>$Revision: 830 $</td></tr>
032 * <tr><td>$Date: 2007-08-20 10:43:04 -0600 (Mon, 20 Aug 2007) $</td></tr>
033 * <tr><td>$Author: dharland $</td></tr>
034 * </table></p>
035 *
036 * @author David M. Harland
037 * @since 2007-03-14
038 */
039 public class OldVlbaSourceCatalogReader
040 extends AbstractSourceCatalogReader
041 {
042 private OldVlbaSourceReader sourceReader;
043 private LineNumberReader dataReader;
044
045 /** Creates a new instance. */
046 public OldVlbaSourceCatalogReader()
047 {
048 sourceReader = new OldVlbaSourceReader();
049 }
050
051 /** Prepares this instance to read from a new source. */
052 private void reset(Reader in, SourceCatalog destination)
053 {
054 catalog = (destination == null) ? new SourceCatalog() : destination;
055
056 readWasSuccessful = false;
057 errors.clear();
058
059 dataReader = new LineNumberReader(in);
060 }
061
062 /**
063 * NOTE: This method closes the incoming Reader!
064 *
065 * @see AbstractSourceCatalogReader#read(java.io.Reader,
066 * edu.nrao.sss.model.source.SourceCatalog)
067 */
068 public boolean read(Reader in, SourceCatalog destination)
069 {
070 reset(in, destination);
071
072 String line = getNextLine();
073
074 while (line != null)
075 {
076 if (sourceReader.textCouldBeData(line))
077 {
078 if (!sourceReader.read(line, dataReader.getLineNumber(), histRecPrefix))
079 errors.addAll(sourceReader.errors);
080
081 if (sourceReader.source != null)
082 {
083 if (sourceInfoOrigin != null)
084 sourceReader.source.setOriginOfInformation(sourceInfoOrigin);
085
086 catalog.addItem(sourceReader.source);
087 }
088 }
089
090 line = getNextLine();
091 }
092
093 try
094 {
095 this.dataReader.close();
096 }
097
098 catch(IOException ioe)
099 {
100 putError(0, "Error closing Reader: " + ioe.getMessage());
101 }
102
103 readWasSuccessful = getErrorCount() == 0;
104
105 return readWasSuccessful;
106 }
107
108 //============================================================================
109 //
110 //============================================================================
111
112 /** Reads lines, returning first one that does not cause an error. */
113 private String getNextLine()
114 {
115 int attempt = 0;
116
117 while (++attempt <= 100)
118 {
119 try {
120 return dataReader.readLine();
121 }
122 catch (IOException ex) {
123 putError("I/O Exception: " + ex.getMessage());
124 }
125 }
126
127 throw new RuntimeException("Failed " + attempt +
128 " times while attempting to read a line.");
129 }
130
131 /** Adds a new parsing error to our list. */
132 private void putError(String message)
133 {
134 putError(dataReader.getLineNumber(), message);
135 }
136 }