001 /*
002 * Copyright 2004-2005 Stephen J. McConnell.
003 * Copyright 2004 Niclas Hedhman.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
014 * implied.
015 *
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 */
019
020 package net.dpml.transit.layout;
021
022 import net.dpml.transit.Artifact;
023 import net.dpml.transit.Layout;
024 import net.dpml.transit.TransitRuntimeException;
025
026 /**
027 * The ModernLayout decodes artifacts into a layout scheme that follows the
028 * convention of group/name/version/expanded-name pattern. Specifically the
029 * layout maps artifacts according to the rule
030 * [group[/[subgroup[/...]]]/[name]/[version]/name[-[version]].type.
031 * Example: <code>artifact:jar:metro/cache/dpml-cache-main#1.0.0</code>
032 * would return the path <code>metro/cache/dpml-cache-main/1.0.0/dpml-cache-main-1.0.0.jar</code>.
033 *
034 * @author <a href="http://www.dpml.net">Digital Product Management Library</a>
035 * @version 2.1.1
036 */
037 public class ModernLayout
038 extends Layout
039 {
040 private static final String LAYOUT_IDENTIFIER = "modern";
041
042 /**
043 * Return the layout identifier. The id value is used
044 * to identify layout instances assigned to cache handlers and
045 * resource host handlers.
046 *
047 * @return the layout id
048 */
049 public String getID()
050 {
051 return LAYOUT_IDENTIFIER;
052 }
053
054 /**
055 * Return the base path for an artifact. The base path is derived from
056 * the artifact group and type. The base path value represents
057 * the directory path relative to a repository root of the directory containing
058 * this artifact.
059 *
060 * @param artifact the resource artifact
061 * @return the base path
062 */
063 public final String resolveBase( Artifact artifact )
064 {
065 String version = artifact.getVersion();
066 if( null == version )
067 {
068 if( null == artifact.getGroup() )
069 {
070 return artifact.getName();
071 }
072 else
073 {
074 String group = getGroupPath( artifact );
075 return group + "/" + artifact.getName();
076 }
077 }
078 else
079 {
080 if( null == artifact.getGroup() )
081 {
082 return artifact.getName() + "/" + version;
083 }
084 else
085 {
086 String group = getGroupPath( artifact );
087 return group + "/" + artifact.getName() + "/" + version;
088 }
089 }
090 }
091
092 /**
093 * Returns the full path of the artifact relative to a logical root directory.
094 * The full path is equivalent to the base path and artifact filename using the
095 * pattern "[base]/[filename]". Path values may be used to resolve an artifact
096 * from a remote repository or local cache relative to the repository or cache
097 * root.
098 *
099 * @param artifact the resource artifact
100 * @see #resolveBase
101 * @see #resolveFilename
102 * @return the logical artifact path
103 */
104 public final String resolvePath( Artifact artifact )
105 {
106 return resolveBase( artifact ) + "/" + resolveFilename( artifact );
107 }
108
109 /**
110 * Return the expanded filename of the artifact. The filename is expressed
111 * as [name]-[version].[type] or in case of a null version simply [name].[type].
112 *
113 * @param artifact the resource artifact
114 * @return the artifact expanded filename
115 */
116 public String resolveFilename( Artifact artifact )
117 {
118 String scheme = artifact.getScheme();
119 String filename = resolveBaseFilename( artifact );
120 if( "artifact".equals( scheme ) )
121 {
122 return filename;
123 }
124 else if( "link".equals( scheme ) )
125 {
126 return filename + ".link";
127 }
128 else
129 {
130 final String error =
131 "Protocol not recognized: " + scheme;
132 throw new TransitRuntimeException( error );
133 }
134 }
135
136 private String resolveBaseFilename( Artifact artifact )
137 {
138 String version = artifact.getVersion();
139 if( null == version )
140 {
141 return artifact.getName() + "." + artifact.getType();
142 }
143 else
144 {
145 return artifact.getName() + "-" + version + "." + artifact.getType();
146 }
147 }
148
149 /**
150 * To be compatible with the maven-2 strategy we need to subsitute period
151 * characters with a group separator.
152 * @param artifact the artifact from which to resolve the group path
153 * @return the group path
154 */
155 private String getGroupPath( Artifact artifact )
156 {
157 String group = artifact.getGroup();
158 return group.replace( '.', '/' );
159 }
160 }