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Java > Open Source Codes > org > apache > tapestry > asset > AssetSourceImpl


1 // Copyright 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.tapestry.asset;
16
17 import java.util.HashMap JavaDoc;
18 import java.util.Iterator JavaDoc;
19 import java.util.List JavaDoc;
20 import java.util.Locale JavaDoc;
21 import java.util.Map JavaDoc;
22
23 import org.apache.hivemind.Location;
24 import org.apache.hivemind.Resource;
25 import org.apache.hivemind.util.Defense;
26 import org.apache.tapestry.IAsset;
27
28 /**
29  * Implementation of the {@link org.apache.tapestry.asset.AssetSource}service interface.
30  *
31  * @author Howard M. Lewis Ship
32  * @since 4.0
33  */
34 public class AssetSourceImpl implements AssetSource
35 {
36     private Map JavaDoc _assetFactoryByPrefix = new HashMap JavaDoc();
37
38     private List JavaDoc _contributions;
39
40     private AssetFactory _defaultAssetFactory;
41
42     private AssetFactory _lookupAssetFactory;
43
44     public void initializeService()
45     {
46         Iterator JavaDoc i = _contributions.iterator();
47         while (i.hasNext())
48         {
49             AssetFactoryContribution c = (AssetFactoryContribution) i.next();
50
51             _assetFactoryByPrefix.put(c.getPrefix(), c.getFactory());
52         }
53     }
54
55     public IAsset findAsset(Resource base, String JavaDoc path, Locale JavaDoc locale, Location location)
56     {
57         Defense.notNull(base, "base");
58         Defense.notNull(path, "path");
59         Defense.notNull(locale, "locale");
60         Defense.notNull(location, "location");
61
62         int colonx = path.indexOf(':');
63
64         if (colonx < 0)
65             return _lookupAssetFactory.createAsset(base, path, locale, location);
66
67         String JavaDoc prefix = path.substring(0, colonx);
68         String JavaDoc truePath = path.substring(colonx + 1);
69
70         AssetFactory factory = (AssetFactory) _assetFactoryByPrefix.get(prefix);
71
72         // Unknown prefix is expected to happen when an external asset (using an established
73 // prefix such as http:) is referenced.
74
75         if (factory == null)
76         {
77             factory = _defaultAssetFactory;
78
79             // Path is the full path, including the prefix (which is really the scheme
80 // of the URL).
81
82             truePath = path;
83         }
84
85         return factory.createAsset(base, truePath, locale, location);
86     }
87
88     /**
89      * Factory used when the path has no prefix, and the type of asset must be inferred from the
90      * type of resource.
91      */
92
93     public void setLookupAssetFactory(AssetFactory lookupAssetFactory)
94     {
95         _lookupAssetFactory = lookupAssetFactory;
96     }
97
98     /**
99      * List of {@link org.apache.tapestry.asset.AssetFactoryContribution}.
100      */
101
102     public void setContributions(List JavaDoc contributions)
103     {
104         _contributions = contributions;
105     }
106
107     /**
108      * Factory used when an unrecognized prefix (typically, an arbitrary URL's scheme) is provided.
109      */
110
111     public void setDefaultAssetFactory(AssetFactory defaultAssetFactory)
112     {
113         _defaultAssetFactory = defaultAssetFactory;
114     }
115
116 }
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