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
{
    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 orig = Arrays.asList(strings);

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

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

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

        Collections.sort(scrambled, new NaturalOrderComparator());

        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			int compareRight(String a, String b)
39			{
40			int bias = 0;
41			int ia = 0;
42			int ib = 0;
43
44			// The longest run of digits wins. That aside, the greatest
45			// value wins, but we can't know that it will until we've scanned
46			// both numbers to know that they have the same magnitude, so we
47			// remember it in BIAS.
48			for (;; ia++, ib++)
49			{
50			char ca = charAt(a, ia);
51			char cb = charAt(b, ib);
52
53			if (!Character.isDigit(ca) && !Character.isDigit(cb))
54			{
55			return bias;
56			}
57			else if (!Character.isDigit(ca))
58			{
59			return -1;
60			}
61			else if (!Character.isDigit(cb))
62			{
63			return +1;
64			}
65			else if (ca < cb)
66			{
67			if (bias == 0)
68			{
69			bias = -1;
70			}
71			}
72			else if (ca > cb)
73			{
74			if (bias == 0)
75			bias = +1;
76			}
77			else if (ca == 0 && cb == 0)
78			{
79			return bias;
80			}
81			}
82			}
83
84			public int compare(T o1, T o2)
85			{
86			String a = o1.toString();
87			String b = o2.toString();
88
89			int ia = 0, ib = 0;
90			int nza = 0, nzb = 0;
91			char ca, cb;
92			int result;
93
94			while (true)
95			{
96			// only count the number of zeroes leading the last number compared
97			nza = nzb = 0;
98
99			ca = charAt(a, ia);
100			cb = charAt(b, ib);
101
102			// skip over leading spaces or zeros
103			while (Character.isSpaceChar(ca) \|\| ca == '0')
104			{
105			if (ca == '0')
106			{
107			nza++;
108			}
109			else
110			{
111			// only count consecutive zeroes
112			nza = 0;
113			}
114
115			ca = charAt(a, ++ia);
116			}
117
118			while (Character.isSpaceChar(cb) \|\| cb == '0')
119			{
120			if (cb == '0')
121			{
122			nzb++;
123			}
124			else
125			{
126			// only count consecutive zeroes
127			nzb = 0;
128			}
129
130			cb = charAt(b, ++ib);
131			}
132
133			// process run of digits
134			if (Character.isDigit(ca) && Character.isDigit(cb))
135			{
136			if ((result = compareRight(a.substring(ia), b.substring(ib))) != 0)
137			{
138			return result;
139			}
140			}
141
142			if (ca == 0 && cb == 0)
143			{
144			// The strings compare the same. Perhaps the caller
145			// will want to call strcmp to break the tie.
146			return nza - nzb;
147			}
148
149			if (ca < cb)
150			{
151			return -1;
152			}
153			else if (ca > cb)
154			{
155			return +1;
156			}
157
158			++ia;
159			++ib;
160			}
161			}
162
163			static char charAt(String s, int i)
164			{
165			if (i >= s.length())
166			{
167			return 0;
168			}
169			else
170			{
171			return s.charAt(i);
172			}
173			}
174
175			public static void main(String[] args)
176			{
177			String[] strings = new String[] { "1-2", "1-02", "1-20", "10-20", "fred", "jane", "pic01",
178			"pic2", "pic02", "pic02a", "pic3", "pic4", "pic 4 else", "pic 5", "pic05", "pic 5",
179			"pic 5 something", "pic 6", "pic 7", "pic100", "pic100a", "pic120", "pic121",
180			"pic02000", "tom", "x2-g8", "x2-y7", "x2-y08", "x8-y8" };
181
182			List orig = Arrays.asList(strings);
183
184			System.out.println("Original: " + orig);
185
186			List scrambled = Arrays.asList(strings);
187			Collections.shuffle(scrambled);
188
189			System.out.println("Scrambled: " + scrambled);
190
191			Collections.sort(scrambled, new NaturalOrderComparator());
192
193			System.out.println("Sorted: " + scrambled);
194			}
195	torben	2531	}