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Groups > comp.lang.java.programmer > #14062

Sorting numeric strings

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Given the following data:

Col1, Col2, Col3
438.23, 991897664, ccc
22.12,  991897631, bbb
100.99, 881897631, aaa
50.12,  991884803, ddd

The class below will sort the data based on the column specified, 
except Col1, which contains float values.  If you set the SortCol 
variable below to 0, sorting does not work.  If you set it to 1 or 2, 
sorting does work.  How can I sort Col1 which is a column of numeric 
strings?

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;

public class SortColumn {

    public static void main(String[] args) throws Exception {

        BufferedReader reader = new BufferedReader(new FileReader("file.csv"));
        //BufferedReader reader = new BufferedReader(new 
FileReader("jtp-input2-test.csv"));
        Map<String, List<String>> map = new TreeMap<String, List<String>>();
        String line = reader.readLine();   //read header
        while ((line = reader.readLine()) != null) {
           String key = getField(line).toString();
           List<String> l = map.get(key);
           if (l == null) {
              l = new LinkedList<String>();
              map.put(key, l);
              System.out.println(key);
           }
        l.add(line);

        }
        reader.close();

        FileWriter writer = new FileWriter("sorted_numbers.txt");
        writer.write("Col1, Col2, Col3\n");
//        writer.write("billnumber, Copay, Discount, NonAllow, unknown\n");
        for (List<String> list : map.values()) {
           for (String val : list) {
               writer.write(val);
               writer.write("\n");
           }
        }
        writer.close();
}

    private static String getField(String line) {
       // Column you want to sort on (Zero based)
       int SortCol = 0;
       return line.split(",")[SortCol];
    }
} 

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Thread

Sorting numeric strings Ben <no@way.com> - 2012-04-30 21:27 -0400
  Re: Sorting numeric strings Arne Vajhøj <arne@vajhoej.dk> - 2012-04-30 21:39 -0400
  Re: Sorting numeric strings Gene Wirchenko <genew@ocis.net> - 2012-05-01 10:30 -0700
  Re: Sorting numeric strings Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-05-01 10:53 -0700
    Re: Sorting numeric strings Roedy Green <see_website@mindprod.com.invalid> - 2012-05-01 14:50 -0700
      Re: Sorting numeric strings Patricia Shanahan <pats@acm.org> - 2012-05-01 15:02 -0700
        Re: Sorting numeric strings Roedy Green <see_website@mindprod.com.invalid> - 2012-05-02 14:36 -0700
          Re: Sorting numeric strings Gene Wirchenko <genew@ocis.net> - 2012-05-02 19:57 -0700
          Re: Sorting numeric strings Dr J R Stockton <reply1218@merlyn.demon.co.uk.not.invalid> - 2012-05-03 19:41 +0100
            Re: Sorting numeric strings Roedy Green <see_website@mindprod.com.invalid> - 2012-05-03 17:40 -0700
              Re: Sorting numeric strings Lew <lewbloch@gmail.com> - 2012-05-03 18:11 -0700
                Re: Sorting numeric strings Martin Gregorie <martin@address-in-sig.invalid> - 2012-05-04 20:01 +0000
                Re: Sorting numeric strings Gene Wirchenko <genew@ocis.net> - 2012-05-04 14:19 -0700
                Re: Sorting numeric strings Martin Gregorie <martin@address-in-sig.invalid> - 2012-05-04 23:36 +0000
                Re: Sorting numeric strings Dr J R Stockton <reply1218@merlyn.demon.co.uk.not.invalid> - 2012-05-06 17:50 +0100
                Re: Sorting numeric strings Gene Wirchenko <genew@ocis.net> - 2012-05-07 10:34 -0700
                Re: Sorting numeric strings Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-05-07 12:38 -0500
                Re: Sorting numeric strings glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-05-07 17:48 +0000
                Re: Sorting numeric strings Gene Wirchenko <genew@ocis.net> - 2012-05-07 11:42 -0700
  Re: Sorting numeric strings Roedy Green <see_website@mindprod.com.invalid> - 2012-05-01 13:38 -0700

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