KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > hivemind > service > impl > ObjectTranslator


1 // Copyright 2004, 2005 The Apache Software Foundation
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 package org.apache.hivemind.service.impl;
16
17 import java.util.HashMap JavaDoc;
18 import java.util.Map JavaDoc;
19
20 import org.apache.hivemind.ApplicationRuntimeException;
21 import org.apache.hivemind.ErrorLog;
22 import org.apache.hivemind.HiveMind;
23 import org.apache.hivemind.Location;
24 import org.apache.hivemind.internal.Module;
25 import org.apache.hivemind.schema.Translator;
26 import org.apache.hivemind.service.ObjectProvider;
27
28 /**
29  * Implementation of the indirect translator. This translator allows the contributor, not the
30  * schema, to define where object values come from, and is fully extensible. Perhaps I'll have an
31  * inspiration and find a better name than "indirect".
32  *
33  * @author Howard Lewis Ship
34  */
35 public class ObjectTranslator implements Translator
36 {
37     /** @since 1.1 */
38     private ErrorLog _errorLog;
39
40     /**
41      * Keyed on prefix, value is an {@link org.apache.hivemind.service.ObjectProvider}.
42      */
43     private Map JavaDoc _providers = new HashMap JavaDoc();
44
45     public Object JavaDoc translate(Module contributingModule, Class JavaDoc propertyType, String JavaDoc inputValue,
46             Location location)
47     {
48         if (HiveMind.isBlank(inputValue))
49             return null;
50
51         int colonx = inputValue.indexOf(':');
52
53         if (colonx < 1)
54         {
55             _errorLog.error(ServiceMessages.invalidProviderSelector(inputValue), null, null);
56
57             return null;
58         }
59
60         String JavaDoc prefix = inputValue.substring(0, colonx);
61
62         ObjectProvider provider = (ObjectProvider) _providers.get(prefix);
63
64         if (provider == null)
65         {
66             _errorLog.error(ServiceMessages.unknownProviderPrefix(prefix), location, null);
67
68             return null;
69         }
70
71         String JavaDoc locator = inputValue.substring(colonx + 1);
72
73         try
74         {
75             return provider.provideObject(contributingModule, propertyType, locator, location);
76         }
77         catch (Exception JavaDoc ex)
78         {
79             throw new ApplicationRuntimeException(ex.getMessage(), location, ex);
80         }
81
82     }
83
84     public void setContributions(Map JavaDoc map)
85     {
86         _providers = map;
87     }
88
89     /** @since 1.1 */
90     public void setErrorLog(ErrorLog errorLog)
91     {
92         _errorLog = errorLog;
93     }
94 }
Popular Tags