KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > smallsql > database > ExpressionFunctionSoundex


1 /* =============================================================
2  * SmallSQL : a free Java DBMS library for the Java(tm) platform
3  * =============================================================
4  *
5  * (C) Copyright 2004-2006, by Volker Berlin.
6  *
7  * Project Info: http://www.smallsql.de/
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22  * USA.
23  *
24  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
25  * in the United States and other countries.]
26  *
27  * ---------------
28  * ExpressionFunctionSoundex.java
29  * ---------------
30  * Author: Volker Berlin
31  *
32  * Created on 18.06.2006
33  */

34 package smallsql.database;
35
36
37 /**
38  * @author Volker Berlin
39  */

40 public class ExpressionFunctionSoundex extends ExpressionFunctionReturnP1StringAndBinary {
41
42     final int getFunction() {
43         return SQLTokenizer.SOUNDEX;
44     }
45
46
47     final boolean isNull() throws Exception JavaDoc {
48         return param1.isNull();
49     }
50
51
52     final byte[] getBytes() throws Exception JavaDoc{
53         throw createUnspportedConversion(SQLTokenizer.BINARY);
54     }
55     
56     
57     final String JavaDoc getString() throws Exception JavaDoc {
58         if(isNull()) return null;
59         String JavaDoc input = param1.getString();
60         return getString(input);
61     }
62      
63     
64     static String JavaDoc getString(String JavaDoc input){
65         char[] output = new char[4];
66         int idx = 0;
67         input = input.toUpperCase();
68         if(input.length()>0){
69             output[idx++] = input.charAt(0);
70         }
71         char last = '0';
72         for(int i=1; idx<4 && i<input.length(); i++){
73             char c = input.charAt(i);
74             switch(c){
75             case 'B':
76             case 'F':
77             case 'P':
78             case 'V':
79                 c = '1';
80                 break;
81             case 'C':
82             case 'G':
83             case 'J':
84             case 'K':
85             case 'Q':
86             case 'S':
87             case 'X':
88             case 'Z':
89                 c = '2';
90                 break;
91             case 'D':
92             case 'T':
93                 c = '3';
94                 break;
95             case 'L':
96                 c = '4';
97                 break;
98             case 'M':
99             case 'N':
100                 c = '5';
101                 break;
102             case 'R':
103                 c = '6';
104                 break;
105             default:
106                 c = '0';
107                 break;
108             }
109             if(c > '0' && last != c){
110                 output[idx++] = c;
111             }
112             last = c;
113         }
114         for(; idx<4;){
115             output[idx++] = '0';
116             
117         }
118         return new String JavaDoc(output);
119     }
120     
121     
122     int getPrecision(){
123         return 4;
124     }
125 }
126
Popular Tags