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	package dk.daoas.daoadresseservice.util;
2
3	import java.io.Serializable;
4
5	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	public class NaturalOrderComparator<T> implements Comparator<T>, Serializable
37	{
38	private static final long serialVersionUID = 1L;
39
40	int compareRight(String a, String b)
41	{
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	List<String> orig = Arrays.asList(strings);
185
186	System.out.println("Original: " + orig);
187
188	List<String> scrambled = Arrays.asList(strings);
189	Collections.shuffle(scrambled);
190
191	System.out.println("Scrambled: " + scrambled);
192
193	Collections.sort(scrambled, new NaturalOrderComparator<String>());
194
195	System.out.println("Sorted: " + scrambled);
196	}
197	}