1 /***
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Exoffice Technologies. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Exoffice Technologies. Exolab is a registered
23 * trademark of Exoffice Technologies.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 2001 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: TypeMapper.java,v 1.4 2003/08/07 13:33:11 tanderson Exp $
44 */
45
46 package org.exolab.jms.tools.db;
47
48 import java.sql.Types;
49 import java.util.HashMap;
50
51 import org.apache.commons.logging.Log;
52 import org.apache.commons.logging.LogFactory;
53
54
55 /***
56 * A helper class for mapping between types.</br>
57 * NOTE: this mapping is not complete, only reflecting those types required
58 * by OpenJMS
59 *
60 * @version $Revision: 1.4 $ $Date: 2003/08/07 13:33:11 $
61 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
62 */
63 class TypeMapper {
64
65 /***
66 * The set of types supported by the RDBMS
67 */
68 private TypeSet _set = null;
69
70 /***
71 * A mapping of SQL type identifiers to their corresponding alternative
72 * types. The alternatives are represented as an array of Type
73 */
74 private HashMap _mappings = new HashMap();
75
76 /***
77 * The logger
78 */
79 private static final Log _log = LogFactory.getLog(TypeMapper.class);
80
81
82 /***
83 * Construct the type mapper with the set of type supported by the
84 * RDBMS
85 */
86 public TypeMapper(TypeSet set) {
87 _set = set;
88
89 // alternatives for the Types.BINARY type
90 Type[] binaries = {new Type(Types.VARBINARY, 0, true),
91 new Type(Types.LONGVARBINARY, 0, true)};
92 add(Types.BINARY, binaries);
93
94 // alternatives for the Types.VARBINARY type
95 Type[] varbinaries = {new Type(Types.LONGVARBINARY, 0, true)};
96 add(Types.VARBINARY, binaries);
97
98 // alternatives for the Types.BIT type
99 Type[] bits = {new Type(Types.CHAR, 0, false),
100 new Type(Types.TINYINT, 0, false),
101 new Type(Types.SMALLINT, 0, false),
102 new Type(Types.INTEGER, 0, false),
103 new Type(Types.NUMERIC, 1, true)};
104 add(Types.BIT, bits);
105
106 // alternatives for the Types.DECIMAL type
107 Type[] decimals = {new Type(Types.NUMERIC, 0, false)};
108 add(Types.DECIMAL, decimals);
109
110 // alternatives for the Types.DATE type
111 Type[] dates = {new Type(Types.TIMESTAMP, 0, false)};
112 add(Types.DATE, dates);
113
114 // alternatives for the Types.BIGINT type
115 long precision = Long.toString(Long.MAX_VALUE).length();
116 Type[] bigints = {new Type(Types.NUMERIC, precision, true)};
117 add(Types.BIGINT, bigints);
118 }
119
120 public Type getType(int type, long precision) {
121 // check if type set supports the requested type directly
122 Type result = _set.getType(type, precision);
123 if (result == null) {
124 // type not supported so return the mapping, if one is available
125 result = (Type) _mappings.get(new Integer(type));
126 }
127 return result;
128 }
129
130 private void add(int type, Type[] mappings) {
131 for (int i = 0; i < mappings.length; ++i) {
132 Type requested = mappings[i];
133 Type supported = _set.getType(requested.getType(),
134 requested.getPrecision());
135 if (supported == null) {
136 _log.debug(
137 "TypeMapper: alternative mapping for type=" +
138 Descriptor.getDescriptor(type).getName() +
139 " is not supported by the database");
140 } else {
141 long precision = requested.getPrecision();
142 long maxPrecision = supported.getPrecision();
143 _log.debug(
144 "TypeMapper: alternative mapping for type=" +
145 Descriptor.getDescriptor(type).getName() +
146 ", precision=" + precision +
147 ", is supported by the database as " + supported);
148 if (type == supported.getType() &&
149 ((precision > 0) && (precision < maxPrecision))) {
150 // if the requested type is supported by the database, and
151 // has a smaller precision, override the maximum precision
152 // defined by the supported type
153 supported = new Type(
154 supported.getType(), supported.getName(),
155 precision, supported.getParameters());
156 }
157 _mappings.put(new Integer(type), supported);
158 break;
159 }
160 }
161 }
162
163 } //-- TypeMapper
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