parse a csv file

shinny · August 11th, 2006, 11:04 AM

Hi there,

I am trying to parse a CSV file, I have a program which will read in the contents of the file and display them to the console and i need to parse some of the fields, which I have no idea how to do
I am trying to get the field info into to an SWT table. The csv file I'm trying to parse has some useless information before and after the file info which is numbered [0-n].
I need to get each relevent line and take its individual pieces of data and store them in an array or something so I can put them into my table i.e. '0:' in one tableItem and 'bla.jpg' in the next tableItem.

Any help or code samples would be much appreciated,

Thanks in advance,

Shinny

--START OF CSV FILE--
File: penDriveImage3.001
Start: Wed Aug 02 19:49:44 2006
Length: 992 MB (1040187392 bytes)

Num Name (bs=512) Size File Offset Comment

0: 8426.jpg 5 KB 4314525 (null) /*THESE LINES ARE IN ONE FIELD EACH!?!*
1: 13578.jpg 42 KB 6952364 (null)
2: 13663.jpg 27 KB 6995952 (null)
3: 13791.jpg 26 KB 7061467 (null)
4: 14825.jpg 46 KB 7590486 (null)
5: 16830.jpg 83 KB 8617069 (null)
6: 16999.jpg 36 KB 8703995 (null)
...RANDOM DATA HERE...
--END OF CSV FILE--

Code:

package GUI;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ReadSource
{
public static void main(String[] arguments)
{
try
{
FileReader file = new FileReader("C:\\audit.csv");
BufferedReader buff = new BufferedReader(file);
boolean eof = false;
while(!eof){
String line = buff.readLine();
if(line == null)
eof = true;
else
System.out.println(line);
}
buff.close();
}
catch(IOException e)
{
System.out.println("Error -- " + e.toString());
}
}

}

panacea · August 16th, 2006, 03:33 AM

Have you looked at String.split(",")?

Jon Emerson
http://www.jonemerson.net/

bhavesh bhanushali · August 29th, 2006, 02:00 PM

Yes u have to use the split method , i have done CSV parsing before . One thing u have to be careful about is that you should eliminate any "," that might be the part of the data in the CSV file otherwise you can have undesired results with data of column n being used as the data of the column n+1 .

ravishakya · September 8th, 2006, 08:14 AM

You can use StringTokenizer to separate individual fields in csv files and read them in or you may use open-source CSV parser classes available at sourceforge.

http://www.ravishakya.com

holdmykidney · September 11th, 2006, 06:26 AM

I have written a CSV-handler class before, and this is qhat I did.

The standard is that any data items that contain a comma are encapsulated in double-quotes.

I replaced any encapsulated commas with the code #44;, and optionally stripped the double-quotes.

You can then split the string based on commas. You can then optionally convert the occurences of #44; within the data back to commas if you wish.

so:
    public static String rationaliseCommas(String sCSVLine, boolean bRetainQuotes)
    {
        // split the string based on quotation marks
        String[] sBroken = sCSVLine.split("\"");
        String sResult="";

        // every OTHER entry was between quotes
        for (int n = 1 ; n < sBroken.length ; n=n+2)
        {
            //encode the comma that was within quotes
            sBroken[n] = sBroken[n].replaceAll(",","#44;");

            // put the quotes back if required
            if (bRetainQuotes)
            {
                sBroken[n] = "\"" + sBroken[n] + "\"";
            }
        }
        for (int n=0 ; n<sBroken.length ; n++)
        {
            sResult+=sBroken[n];
        }
        return sResult;
    }

For large CSV lines you should really use StringBuffers instead of Strings, but you get the idea