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Java > Open Source Codes > org > jboss > ejb > plugins > cmp > jdbc > AliasManager


1 /*
2 * JBoss, Home of Professional Open Source
3 * Copyright 2005, JBoss Inc., and individual contributors as indicated
4 * by the @authors tag. See the copyright.txt in the distribution for a
5 * full listing of individual contributors.
6 *
7 * This is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 2.1 of
10 * the License, or (at your option) any later version.
11 *
12 * This software is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this software; if not, write to the Free
19 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21 */
22 package org.jboss.ejb.plugins.cmp.jdbc;
23
24 import java.util.Map JavaDoc;
25 import java.util.HashMap JavaDoc;
26
27
28 /**
29  * This class manages aliases for generated queries.
30  *
31  * @author <a HREF="mailto:dain@daingroup.com">Dain Sundstrom</a>
32  * @version $Revision: 37459 $
33  */
34 final class AliasManager
35 {
36    private static final String JavaDoc RELATION_TABLE_SUFFIX = "_RELATION_TABLE";
37
38    private final String JavaDoc prefix;
39    private final String JavaDoc suffix;
40    private final int maxLength;
41    private final Map JavaDoc aliases = new HashMap JavaDoc();
42    private final Map JavaDoc relationTableAliases = new HashMap JavaDoc();
43
44    private int count = 0;
45
46    public AliasManager(String JavaDoc prefix, String JavaDoc suffix, int maxLength)
47    {
48       this.prefix = prefix;
49       this.suffix = suffix;
50       this.maxLength = maxLength;
51    }
52
53    public String JavaDoc getAlias(String JavaDoc path)
54    {
55       String JavaDoc alias = (String JavaDoc)aliases.get(path);
56       if(alias == null)
57       {
58          alias = createAlias(path);
59          aliases.put(path, alias);
60       }
61       return alias;
62    }
63
64    private String JavaDoc createAlias(String JavaDoc path)
65    {
66       StringBuffer JavaDoc alias = new StringBuffer JavaDoc();
67       alias.append(prefix).append(count++).append(suffix);
68       alias.append(path.replace('.', '_'));
69
70       return alias.substring(0, Math.min(maxLength, alias.length()));
71    }
72
73    public void addAlias(String JavaDoc path, String JavaDoc alias)
74    {
75       aliases.put(path, alias);
76    }
77
78    public String JavaDoc getRelationTableAlias(String JavaDoc path)
79    {
80       String JavaDoc relationTableAlias = (String JavaDoc)relationTableAliases.get(path);
81       if(relationTableAlias == null)
82       {
83          relationTableAlias = createRelationTableAlias(path);
84          relationTableAliases.put(path, relationTableAlias);
85       }
86       return relationTableAlias;
87    }
88
89    private String JavaDoc createRelationTableAlias(String JavaDoc path)
90    {
91       StringBuffer JavaDoc relationTableAlias = new StringBuffer JavaDoc();
92
93       relationTableAlias.append(prefix).append(count++).append(suffix);
94
95       relationTableAlias.append(path.replace('.', '_'));
96       relationTableAlias.append(RELATION_TABLE_SUFFIX);
97
98       return relationTableAlias.substring(
99          0, Math.min(maxLength, relationTableAlias.length()));
100    }
101 }
102
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