How sort CSV file with some columns in java

Question

I try to sort a tab-delimited file based on the value of three columns. But it did not sort correctly.How can I solve this problem? I used the code written in this page .

The output is this:

    clueweb09-en0000-12-00000   10722   10732   0.995358    0.000336    /m/0cbx95
    clueweb09-en0000-12-00000   10736   10746   0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   11230   11237   0.829546    0.000291    /m/03jm5
    clueweb09-en0000-12-00000   13009   13024   0.540326    0.000085    /m/012qgt
    clueweb09-en0000-12-00000   13050   13060   0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   1338    1348    0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   1864    1874    0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   2018    2028    0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   2745    2752    0.78671     0.000722    /m/02jx1
    clueweb09-en0000-12-00000   2823    2829    0.956747    0.000476    /m/04jpl
    clueweb09-en0000-12-00000   2856    2862    0.649632    0.000007    /m/0gs0g

I want this output:

    clueweb09-en0000-12-00000   1338    1348    0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   1864    1874    0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   2018    2028    0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   2745    2752    0.78671     0.000722    /m/02jx1
    clueweb09-en0000-12-00000   2823    2829    0.956747    0.000476    /m/04jpl
    clueweb09-en0000-12-00000   2856    2862    0.649632    0.000007    /m/0gs0g
    clueweb09-en0000-12-00000   10722   10732   0.995358    0.000336    /m/0cbx95
    clueweb09-en0000-12-00000   10736   10746   0.950789    0.000697    /m/01n7q
    clueweb09-en0000-12-00000   11230   11237   0.829546    0.000291    /m/03jm5
    clueweb09-en0000-12-00000   13009   13024   0.540326    0.000085    /m/012qgt
    clueweb09-en0000-12-00000   13050   13060   0.950789    0.000697    /m/01n7q

Answer 1

write a your own comparator for the columns you want to sort.As Walter said currently you will get the data as string,Convert that to list of object and sort using comparator. Hope this helps.

Answer 2

The numbers are treated at this moment as strings but they are left aligned and sorted that way. You need to change the compare function to deal with this or, when you read the file transform those numbers to right aligned strings.

Answer 3

I solve the problem by changing the compare function of this page to the following code.

private static <T> Comparator<List<T>> createComparator(
        final Comparator<? super T> delegate, final int... indices)
    {
        return new Comparator<List<T>>()
        {
            @Override
            public int compare(List<T> list0, List<T> list1)
            {

                    T element0 = list0.get(indices[0]);
                    T element1 = list1.get(indices[0]);
                    int n = delegate.compare(element0, element1);
                    if (n != 0)
                    {
                        return n;
                    }
                    else
                        return Integer.compare(Integer.parseInt(list0.get(indices[1]).toString()), Integer.parseInt(list1.get(indices[1]).toString()));
            }
        };
    }