Package de.mhus.lib.core.io

Class CSVReader

  • public class CSVReader
extends Object
    Read CSV (Comma Separated Value) files. This format is used my Microsoft Word and Excel. Fields are separated by commas, and enclosed in quotes if they contain commas or quotes. Embedded quotes are doubled. Embedded spaces do not normally require surrounding quotes. The last field on the line is not followed by a comma. Null fields are represented by two commas in a row. We optionally trim leading and trailing spaces on fields, even inside quotes. File must normally end with a single CrLf, other wise you will get a null when trying to read a field on older JVMs.
    Author:
    copyright (c) 2002-2006 Roedy Green Canadian Mind Products version 1.0 2002 March 27
    1.1 2002 March 28 - close - configurable separator char - no longer sensitive to line-ending convention. - uses a categorise routine to massage categories for use in case clauses. - faster skipToNextLine
    1.2 2002 April 23 - put in to separate package
    1.4 2002 April 19 - fix bug if last field on line is empty, was not counting as a field.
    1.6 2002 May 25 - allow choice of " or ' quote char.
    1.7 2002 August 29 - getAllFieldsInLine
    1.8 2002 November 12 - allow Microsoft Excel format fields that can span several lines. sponsored by Steve Hunter of agilense.com
    1.9 2002 November 14 - trim parameter to control whether fields are trimmed of lead/trail whitespace (blanks, Cr, Lf, Tab etc.)
    2.0 2003 August 10 - getInt, getLong, getFloat, getDouble
    2.1 2005-07-16 - reorganisation, new bat files.
    2.2 2005-08-28 - add CSVAlign and CSVPack to the suite.

    There is another CSVReader at: at http://ostermiller.org/utils/ExcelCSV.html If this CSVReader is not suitable for you, try that one.
    There is one written in C# at http://www.csvreader.com/
    Future ideas:
    1. allow specify various comment chars that mean the rest of the line should be ignored. e.g. ; ! #. These chars have to be in quotes in data then.
    2. allow \ to be used for quoting characters.

    • Constructor Detail

      • CSVReader

        public CSVReader​(Reader r)
        convenience Constructor, default to comma separator, " for quote, no multiline fields, with trimming.
        Parameters:
        r - input Reader source of CSV Fields to read.

      • CSVReader

        public CSVReader​(Reader r,
                 char separator,
                 char quote,
                 boolean allowMultiLineFields,
                 boolean trim)
        Constructor
        Parameters:
        r - input Reader source of CSV Fields to read.
        separator - field separator character, usually ',' in North America, ';' in Europe and sometimes '\t' for tab.
        quote - char to use to enclose fields containing a separator, usually '\"'
        allowMultiLineFields - true if reader should allow quoted fields to span more than one line. Microsoft Excel sometimes generates files like this.
        trim - true if reader should trim lead/trailing whitespace e.g. blanks, Cr, Lf. Tab off fields.

    • Method Detail

      • get

        public String get()
           throws EOFException,
                  IOException
        Read one field from the CSV file
        Returns:
        String value, even if the field is numeric. Surrounded and embedded double quotes are stripped. possibly "". null means end of line.
        Throws:
        EOFException - at end of file after all the fields have been read.
        IOException - Some problem reading the file, possibly malformed data.

      • skip

        public void skip​(int fields)
          throws EOFException,
                 IOException
        Skip over fields you don't want to process.
        Parameters:
        fields - How many field you want to bypass reading. The newline counts as one field.
        Throws:
        EOFException - at end of file after all the fields have been read.
        IOException - Some problem reading the file, possibly malformed data.

      • skipToNextLine

        public void skipToNextLine()
                    throws EOFException,
                           IOException
        Skip over remaining fields on this line you don't want to process.
        Throws:
        EOFException - at end of file after all the fields have been read.
        IOException - Some problem reading the file, possibly malformed data.

      • getRowNames

        public String[] getRowNames()

      • get

        public String get​(int row)

      • getLineCount

        public int getLineCount()

      • getLineColumns

        public int getLineColumns()

      • getCurrentLine

        public String[] getCurrentLine()

      • main

        public static void main​(String[] args)
        Test driver
        Parameters:
        args - not used