KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > com > caucho > amber > expr > OneToOneSchemaExpr


1 /*
2  * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  * Free Software Foundation, Inc.
23  * 59 Temple Place, Suite 330
24  * Boston, MA 02111-1307 USA
25  *
26  * @author Rodrigo Westrupp
27  */
28
29 package com.caucho.amber.expr;
30
31 import com.caucho.amber.field.AmberField;
32 import com.caucho.amber.query.FromItem;
33 import com.caucho.amber.query.QueryParseException;
34 import com.caucho.amber.query.QueryParser;
35 import com.caucho.amber.type.RelatedType;
36 import com.caucho.util.L10N;
37
38 /**
39  * Represents an association from a from-item table.
40  */
41 public class OneToOneSchemaExpr extends SchemaExpr {
42   private static final L10N L = new L10N(OneToOneSchemaExpr.class);
43
44   private DependentEntityOneToOneExpr _expr;
45   private String JavaDoc _name;
46
47   /**
48    * Creates the association schema.
49    */
50   public OneToOneSchemaExpr(DependentEntityOneToOneExpr expr,
51                             String JavaDoc name)
52   {
53     _expr = expr;
54     _name = name;
55   }
56
57   /**
58    * Returns the tail name.
59    */
60   public String JavaDoc getTailName()
61   {
62     return _name;
63   }
64
65   /**
66    * Creates a field-based schema.
67    */
68   public SchemaExpr createField(QueryParser parser, String JavaDoc name)
69     throws QueryParseException
70   {
71     RelatedType type = _expr.getTargetType();
72
73     AmberField field = type.getField(name);
74
75     if (field == null)
76       throw parser.error(L.l("{0}: '{1}' is an unknown field.",
77                              type.getBeanClass().getName(),
78                              name));
79
80     AmberExpr fieldExpr = _expr.createField(parser, name);
81
82     if (fieldExpr instanceof ManyToOneExpr)
83       return new ManyToOneSchemaExpr((ManyToOneExpr) fieldExpr, name);
84
85     if (fieldExpr instanceof DependentEntityOneToOneExpr)
86       return new OneToOneSchemaExpr((DependentEntityOneToOneExpr) fieldExpr,
87                                     name);
88
89     throw parser.error(L.l("{0}: '{1}' must be a collection or one-to-one relationship.",
90                            type.getBeanClass().getName(),
91                            name));
92   }
93
94   /**
95    * Adds the from item.
96    */
97   public FromItem addFromItem(QueryParser parser, String JavaDoc id)
98     throws QueryParseException
99   {
100     _expr = (DependentEntityOneToOneExpr) _expr.bindSelect(parser, id);
101
102     FromItem fromItem = _expr.bindSubPath(parser);
103
104     return fromItem;
105   }
106 }
107
Popular Tags