daoadresseservice/util/NaturalOrderComparator.java

package dk.daoas.daoadresseservice.util;

import java.io.Serializable;

import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/*
NaturalOrderComparator.java -- Perform 'natural order' comparisons of strings in Java.
Copyright (C) 2003 by Pierre-Luc Paour <natorder@paour.com>

Based on the C version by Martin Pool, of which this is more or less a straight conversion.
Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>

This software is provided 'as-is', without any express or implied
warranty.  In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/


public class NaturalOrderComparator<T> implements Comparator<T>, Serializable
{
        private static final long serialVersionUID = 1L;

        int compareRight(String a, String b)
    {
        int bias = 0;
        int ia = 0;
        int ib = 0;

        // The longest run of digits wins. That aside, the greatest
        // value wins, but we can't know that it will until we've scanned
        // both numbers to know that they have the same magnitude, so we
        // remember it in BIAS.
        for (;; ia++, ib++)
        {
            char ca = charAt(a, ia);
            char cb = charAt(b, ib);

            if (!Character.isDigit(ca) && !Character.isDigit(cb))
            {
                return bias;
            }
            else if (!Character.isDigit(ca))
            {
                return -1;
            }
            else if (!Character.isDigit(cb))
            {
                return +1;
            }
            else if (ca < cb)
            {
                if (bias == 0)
                {
                    bias = -1;
                }
            }
            else if (ca > cb)
            {
                if (bias == 0)
                    bias = +1;
            }
            else if (ca == 0 && cb == 0)
            {
                return bias;
            }
        }
    }

    public int compare(T o1, T o2)
    {
        String a = o1.toString();
        String b = o2.toString();

        int ia = 0, ib = 0;
        int nza = 0, nzb = 0;
        char ca, cb;
        int result;

        while (true)
        {
            // only count the number of zeroes leading the last number compared
            nza = nzb = 0;

            ca = charAt(a, ia);
            cb = charAt(b, ib);

            // skip over leading spaces or zeros
            while (Character.isSpaceChar(ca) || ca == '0')
            {
                if (ca == '0')
                {
                    nza++;
                }
                else
                {
                    // only count consecutive zeroes
                    nza = 0;
                }

                ca = charAt(a, ++ia);
            }

            while (Character.isSpaceChar(cb) || cb == '0')
            {
                if (cb == '0')
                {
                    nzb++;
                }
                else
                {
                    // only count consecutive zeroes
                    nzb = 0;
                }

                cb = charAt(b, ++ib);
            }

            // process run of digits
            if (Character.isDigit(ca) && Character.isDigit(cb))
            {
                if ((result = compareRight(a.substring(ia), b.substring(ib))) != 0)
                {
                    return result;
                }
            }

            if (ca == 0 && cb == 0)
            {
                // The strings compare the same. Perhaps the caller
                // will want to call strcmp to break the tie.
                return nza - nzb;
            }

            if (ca < cb)
            {
                return -1;
            }
            else if (ca > cb)
            {
                return +1;
            }

            ++ia;
            ++ib;
        }
    }

    static char charAt(String s, int i)
    {
        if (i >= s.length())
        {
            return 0;
        }
        else
        {
            return s.charAt(i);
        }
    }

    public static void main(String[] args)
    {
        String[] strings = new String[] { "1-2", "1-02", "1-20", "10-20", "fred", "jane", "pic01",
            "pic2", "pic02", "pic02a", "pic3", "pic4", "pic 4 else", "pic 5", "pic05", "pic 5",
            "pic 5 something", "pic 6", "pic   7", "pic100", "pic100a", "pic120", "pic121",
            "pic02000", "tom", "x2-g8", "x2-y7", "x2-y08", "x8-y8" };

        List<String> orig = Arrays.asList(strings);

        System.out.println("Original: " + orig);

        List<String> scrambled = Arrays.asList(strings);
        Collections.shuffle(scrambled);

        System.out.println("Scrambled: " + scrambled);

        Collections.sort(scrambled, new NaturalOrderComparator<String>());

        System.out.println("Sorted: " + scrambled);
    }
}
1	torben	2495	package dk.daoas.daoadresseservice.util;
2
3	torben	2531	import java.io.Serializable;
4
5	torben	2495	import java.util.Arrays;
6			import java.util.Collections;
7			import java.util.Comparator;
8			import java.util.List;
9
10			/*
11			NaturalOrderComparator.java -- Perform 'natural order' comparisons of strings in Java.
12			Copyright (C) 2003 by Pierre-Luc Paour <natorder@paour.com>
13
14			Based on the C version by Martin Pool, of which this is more or less a straight conversion.
15			Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>
16
17			This software is provided 'as-is', without any express or implied
18			warranty. In no event will the authors be held liable for any damages
19			arising from the use of this software.
20
21			Permission is granted to anyone to use this software for any purpose,
22			including commercial applications, and to alter it and redistribute it
23			freely, subject to the following restrictions:
24
25			1. The origin of this software must not be misrepresented; you must not
26			claim that you wrote the original software. If you use this software
27			in a product, an acknowledgment in the product documentation would be
28			appreciated but is not required.
29			2. Altered source versions must be plainly marked as such, and must not be
30			misrepresented as being the original software.
31			3. This notice may not be removed or altered from any source distribution.
32			*/
33
34
35
36	torben	2531	public class NaturalOrderComparator<T> implements Comparator<T>, Serializable
37	torben	2495	{
38	torben	2537	private static final long serialVersionUID = 1L;
39
40			int compareRight(String a, String b)
41	torben	2495	{
42			int bias = 0;
43			int ia = 0;
44			int ib = 0;
45
46			// The longest run of digits wins. That aside, the greatest
47			// value wins, but we can't know that it will until we've scanned
48			// both numbers to know that they have the same magnitude, so we
49			// remember it in BIAS.
50			for (;; ia++, ib++)
51			{
52			char ca = charAt(a, ia);
53			char cb = charAt(b, ib);
54
55			if (!Character.isDigit(ca) && !Character.isDigit(cb))
56			{
57			return bias;
58			}
59			else if (!Character.isDigit(ca))
60			{
61			return -1;
62			}
63			else if (!Character.isDigit(cb))
64			{
65			return +1;
66			}
67			else if (ca < cb)
68			{
69			if (bias == 0)
70			{
71			bias = -1;
72			}
73			}
74			else if (ca > cb)
75			{
76			if (bias == 0)
77			bias = +1;
78			}
79			else if (ca == 0 && cb == 0)
80			{
81			return bias;
82			}
83			}
84			}
85
86			public int compare(T o1, T o2)
87			{
88			String a = o1.toString();
89			String b = o2.toString();
90
91			int ia = 0, ib = 0;
92			int nza = 0, nzb = 0;
93			char ca, cb;
94			int result;
95
96			while (true)
97			{
98			// only count the number of zeroes leading the last number compared
99			nza = nzb = 0;
100
101			ca = charAt(a, ia);
102			cb = charAt(b, ib);
103
104			// skip over leading spaces or zeros
105			while (Character.isSpaceChar(ca) \|\| ca == '0')
106			{
107			if (ca == '0')
108			{
109			nza++;
110			}
111			else
112			{
113			// only count consecutive zeroes
114			nza = 0;
115			}
116
117			ca = charAt(a, ++ia);
118			}
119
120			while (Character.isSpaceChar(cb) \|\| cb == '0')
121			{
122			if (cb == '0')
123			{
124			nzb++;
125			}
126			else
127			{
128			// only count consecutive zeroes
129			nzb = 0;
130			}
131
132			cb = charAt(b, ++ib);
133			}
134
135			// process run of digits
136			if (Character.isDigit(ca) && Character.isDigit(cb))
137			{
138			if ((result = compareRight(a.substring(ia), b.substring(ib))) != 0)
139			{
140			return result;
141			}
142			}
143
144			if (ca == 0 && cb == 0)
145			{
146			// The strings compare the same. Perhaps the caller
147			// will want to call strcmp to break the tie.
148			return nza - nzb;
149			}
150
151			if (ca < cb)
152			{
153			return -1;
154			}
155			else if (ca > cb)
156			{
157			return +1;
158			}
159
160			++ia;
161			++ib;
162			}
163			}
164
165			static char charAt(String s, int i)
166			{
167			if (i >= s.length())
168			{
169			return 0;
170			}
171			else
172			{
173			return s.charAt(i);
174			}
175			}
176
177			public static void main(String[] args)
178			{
179			String[] strings = new String[] { "1-2", "1-02", "1-20", "10-20", "fred", "jane", "pic01",
180			"pic2", "pic02", "pic02a", "pic3", "pic4", "pic 4 else", "pic 5", "pic05", "pic 5",
181			"pic 5 something", "pic 6", "pic 7", "pic100", "pic100a", "pic120", "pic121",
182			"pic02000", "tom", "x2-g8", "x2-y7", "x2-y08", "x8-y8" };
183
184	torben	2537	List<String> orig = Arrays.asList(strings);
185	torben	2495
186			System.out.println("Original: " + orig);
187
188	torben	2537	List<String> scrambled = Arrays.asList(strings);
189	torben	2495	Collections.shuffle(scrambled);
190
191			System.out.println("Scrambled: " + scrambled);
192
193	torben	2537	Collections.sort(scrambled, new NaturalOrderComparator<String>());
194	torben	2495
195			System.out.println("Sorted: " + scrambled);
196			}
197	torben	2531	}