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Java > Open Source Codes > smallsql > database > ExpressionFunctionRight


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  * ExpressionFunctionRight.java
29  * ---------------
30  * Author: Volker Berlin
31  *
32  * Created on 29.06.2004
33  */

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

40 public class ExpressionFunctionRight extends ExpressionFunctionReturnP1StringAndBinary {
41
42     final int getFunction() {
43         return SQLTokenizer.RIGHT;
44     }
45
46
47     final boolean isNull() throws Exception JavaDoc {
48         return param1.isNull() || param2.isNull();
49     }
50
51
52     final byte[] getBytes() throws Exception JavaDoc{
53         if(isNull()) return null;
54         byte[] bytes = param1.getBytes();
55         int length = param2.getInt();
56         if(bytes.length <= length) return bytes;
57
58         byte[] b = new byte[length];
59         System.arraycopy(bytes, bytes.length -length, b, 0, length);
60         return b;
61     }
62     
63     
64     final String JavaDoc getString() throws Exception JavaDoc {
65         if(isNull()) return null;
66         String JavaDoc str = param1.getString();
67         int length = param2.getInt();
68         int start = str.length() - Math.min( length, str.length() );
69         return str.substring(start);
70     }
71
72
73 }
74
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