//---------------------------------------------------------------------------||
// csvParser.java                                                            ||
//                                                                           ||
// This code takes a comma-separated value (CSV) file as input, and converts ||
// it to XML.  The entire document is enclosed in a <document> tag, each row ||
// is enclosed in a <row> tag, and the tag names for the individual data     ||
// items are based on the column number in the file.                         ||
//---------------------------------------------------------------------------||
// Created 21 March 2000 by Doug Tidwell, based on a question from           ||
// Tom Watson (!) of Schwab.                                                 ||
//---------------------------------------------------------------------------||

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.StreamTokenizer;
import java.math.BigInteger;

public class csvParser
{
  public void csvToXML(String inputFile, String outputFile)
    throws java.io.FileNotFoundException, 
           java.io.IOException
  {
    BufferedReader br = new BufferedReader(new FileReader(inputFile));
    StreamTokenizer st = new StreamTokenizer(br);
    // We want to read the file one line at a time, so end-ofline matters
    st.eolIsSignificant(true);
    // The delimiter between fields is a comma, not a space
    st.whitespaceChars(',', ',');
    // All strings are in double quotes
    st.quoteChar('"');

    FileWriter fw = new FileWriter(outputFile);
    // Write the XML declaration and the root element
    fw.write("<?xml version=\"1.0\"?>\n");
    fw.write("<document>\n");

    // Get the first token, then check its type
    st.nextToken();
    while (st.ttype != StreamTokenizer.TT_EOF)
    {
      // We're not at EOF, so start a row
      fw.write("  <row>\n");
      int i = 1;
      while (st.ttype != StreamTokenizer.TT_EOL && 
             st.ttype != StreamTokenizer.TT_EOF)
      {
        // We use the BigInteger class here to write long numbers out
        // Without this, the date fields (which are written something 
        // like (19991013) get converted to scientific notation....
        if (st.ttype == StreamTokenizer.TT_NUMBER)
        {
          fw.write("    <column" + i + ">");
          fw.write((BigInteger.valueOf((long)st.nval)).toString());
          fw.write("</column" + i++ + ">\n");
        }
        else if (st.ttype != StreamTokenizer.TT_EOL &&
                 st.ttype != StreamTokenizer.TT_EOF)
        {
          // For reasons that escape me, if the token is "+", it
          // is interpreted as NULL.
          if (st.sval != null)
          {
            fw.write("    <column" + i + ">");
            fw.write(st.sval.trim());
            fw.write("</column" + i++ + ">\n");
          }
        }
        st.nextToken();
      }

      // We've hit either the end of the line or the end of the file,
      // so close the row.
      fw.write("  </row>\n");
      st.nextToken();
    }

    // Now we're at the end of the file, so close the XML document, 
    // flush the buffer to disk, and close the newly-created file. 
    fw.write("</document>\n");
    fw.flush();
    fw.close();
  }

  public static void main(String argv[])
    throws java.io.IOException
  {
    if (argv.length == 2)
    {
      csvParser cp = new csvParser();
      cp.csvToXML(argv[0], argv[1]);
    }
    else
    {
      System.out.println("\nUsage: java csvToXML csv-file xml-file");
      System.out.println("       where csv-file is the comma-separated file, and ");
      System.out.println("       xml-file is the XML file to be generated.");
    }
  }
}