Java List Sort sort(final List list)

Description

Sorts the specified string list.

License

Open Source License

Parameter

Parameter	Description
list	String list containing the elements to be sorted. Can be <code>null</code>.

Return

Sorted string list or null if null was passed in.

Declaration

public static List<String> sort(final List<String> list) 

Method Source Code

//package com.java2s;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public class Main {
    /**/*  w  w w . j a  v  a 2s.  com*/
     * Sorts the specified string list. O(N) is n log(n).
     *
     * @param  list String list containing the elements to be sorted. Can be <code>null</code>.
     *
     * @return Sorted string list or <code>null</code> if <code>null</code> was passed in.
     */
    public static List<String> sort(final List<String> list) {
        List<String> listSorted = null;

        if (list != null) {
            listSorted = new ArrayList<String>();
            for (final String str : list) {
                listSorted.add(getIndexForSortedInsert(listSorted, str), str);
            }
        }

        return listSorted;
    }

    /**
     * Sorts the specified string list. O(N) is n log(n).
     * 
     * @param set String set containing the elements to be sorted. Can be
     *            <code>null</code>.
     * 
     * @return Sorted string list or <code>null</code> if <code>null</code> was
     *         passed in.
     */
    public static List<String> sort(final Set<String> set) {
        List<String> listSorted = null;

        if (set != null) {
            listSorted = new ArrayList<String>();
            for (final String str : set) {
                listSorted.add(getIndexForSortedInsert(listSorted, str), str);
            }
        }

        return listSorted;
    }

    /**
     * Determines for a sorted list and an object, what index the string
     * could be inserted. Note: This method just returns the index, but does not
     * insert the string.
     * 
     * @param listSorted
     *            Sorted string list. Can be <code>null</code>.
     * @param item
     *            String to be inserted. Can be <code>null</code>.
     * 
     * @return Index for string insertion.
     */
    private static int getIndexForSortedInsert(final List<String> listSorted, final String item) {
        if (listSorted == null || item == null) {
            return 0;
        }

        int low = 0;
        int high = listSorted.size() - 1;

        while (low <= high) {
            final int mid = (low + high) >>> 1;
            final String midVal = listSorted.get(mid);
            final int cmp = midVal.compareToIgnoreCase(item);

            if (cmp < 0) {
                low = mid + 1;
            } else if (cmp > 0) {
                high = mid - 1;
            } else {
                return mid; // key found
            }
        }

        return low; // key not found.
    }
}

Related

1. setToSortedList(final Set set, final Comparator comparator)
2. sort( S list)
3. sort(Collection list)
4. Sort(Collection list)
5. sort(Collection list)
6. sort(List list)
7. sort(List list)
8. sort(List list)
9. sort(List list, Comparator comparator)