01: /*
02: * JBoss, Home of Professional Open Source.
03: * Copyright 2006, Red Hat Middleware LLC, and individual contributors
04: * as indicated by the @author tags. See the copyright.txt file in the
05: * distribution for a full listing of individual contributors.
06: *
07: * This is free software; you can redistribute it and/or modify it
08: * under the terms of the GNU Lesser General Public License as
09: * 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;
25: import java.util.HashMap;
26:
27: /**
28: * This class manages aliases for generated queries.
29: *
30: * @author <a href="mailto:dain@daingroup.com">Dain Sundstrom</a>
31: * @version $Revision: 57209 $
32: */
33: final class AliasManager {
34: private static final String RELATION_TABLE_SUFFIX = "_RELATION_TABLE";
35:
36: private final String prefix;
37: private final String suffix;
38: private final int maxLength;
39: private final Map aliases = new HashMap();
40: private final Map relationTableAliases = new HashMap();
41:
42: private int count = 0;
43:
44: public AliasManager(String prefix, String suffix, int maxLength) {
45: this .prefix = prefix;
46: this .suffix = suffix;
47: this .maxLength = maxLength;
48: }
49:
50: public String getAlias(String path) {
51: String alias = (String) aliases.get(path);
52: if (alias == null) {
53: alias = createAlias(path);
54: aliases.put(path, alias);
55: }
56: return alias;
57: }
58:
59: private String createAlias(String path) {
60: StringBuffer alias = new StringBuffer();
61: alias.append(prefix).append(count++).append(suffix);
62: alias.append(path.replace('.', '_'));
63:
64: return alias.substring(0, Math.min(maxLength, alias.length()));
65: }
66:
67: public void addAlias(String path, String alias) {
68: aliases.put(path, alias);
69: }
70:
71: public String getRelationTableAlias(String path) {
72: String relationTableAlias = (String) relationTableAliases
73: .get(path);
74: if (relationTableAlias == null) {
75: relationTableAlias = createRelationTableAlias(path);
76: relationTableAliases.put(path, relationTableAlias);
77: }
78: return relationTableAlias;
79: }
80:
81: private String createRelationTableAlias(String path) {
82: StringBuffer relationTableAlias = new StringBuffer();
83:
84: relationTableAlias.append(prefix).append(count++)
85: .append(suffix);
86:
87: relationTableAlias.append(path.replace('.', '_'));
88: relationTableAlias.append(RELATION_TABLE_SUFFIX);
89:
90: return relationTableAlias.substring(0, Math.min(maxLength,
91: relationTableAlias.length()));
92: }
93: }
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