1 package org.apache.maven.plugins.dependency.tree;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.io.Writer;
23 import java.util.ArrayList;
24 import java.util.List;
25
26 import org.apache.maven.shared.dependency.graph.DependencyNode;
27 import org.apache.maven.shared.dependency.graph.traversal.DependencyNodeVisitor;
28
29 /**
30 * A dependency node visitor that serializes visited nodes to a writer using the TGF format.
31 * http://en.wikipedia.org/wiki/Trivial_Graph_Format
32 *
33 * @author <a href="mailto:jerome.creignou@gmail.com">Jerome Creignou</a>
34 * @since 2.1
35 */
36 public class TGFDependencyNodeVisitor
37 extends AbstractSerializingVisitor
38 implements DependencyNodeVisitor
39 {
40
41 /**
42 * Utiity class to write an Edge.
43 *
44 * @author <a href="mailto:jerome.creignou@gmail.com">Jerome Creignou</a>
45 */
46 static final class EdgeAppender
47 {
48 /**
49 * Edge start.
50 */
51 private DependencyNode from;
52
53 /**
54 * Edge end.
55 */
56 private DependencyNode to;
57
58 /**
59 * Edge label. (optional)
60 */
61 private String label;
62
63 /**
64 * Build a new EdgeAppender.
65 *
66 * @param from edge start.
67 * @param to edge end
68 * @param label optional label.
69 */
70 EdgeAppender( DependencyNode from, DependencyNode to, String label )
71 {
72 super();
73 this.from = from;
74 this.to = to;
75 this.label = label;
76 }
77
78 /**
79 * build a string representing the edge.
80 */
81 @Override
82 public String toString()
83 {
84 StringBuilder result = new StringBuilder( generateId( from ) );
85 result.append( ' ' ).append( generateId( to ) );
86 if ( label != null )
87 {
88 result.append( ' ' ).append( label );
89 }
90 return result.toString();
91 }
92
93 }
94
95 /**
96 * List of edges.
97 */
98 private List<EdgeAppender> edges = new ArrayList<EdgeAppender>();
99
100 /**
101 * Constructor.
102 *
103 * @param writer the writer to write to.
104 */
105 public TGFDependencyNodeVisitor( Writer writer )
106 {
107 super( writer );
108 }
109
110 /**
111 * {@inheritDoc}
112 */
113 @Override
114 public boolean endVisit( DependencyNode node )
115 {
116 if ( node.getParent() == null || node.getParent() == node )
117 {
118 // dump edges on last node endVisit
119 writer.println( "#" );
120 for ( EdgeAppender edge : edges )
121 {
122 writer.println( edge.toString() );
123 }
124 }
125 else
126 {
127 DependencyNode p = node.getParent();
128 // using scope as edge label.
129 edges.add( new EdgeAppender( p, node, node.getArtifact().getScope() ) );
130 }
131 return true;
132 }
133
134 /**
135 * {@inheritDoc}
136 */
137 @Override
138 public boolean visit( DependencyNode node )
139 {
140 // write node
141 writer.write( generateId( node ) );
142 writer.write( " " );
143 writer.println( node.toNodeString() );
144 return true;
145 }
146
147 /**
148 * Generate a unique id from a DependencyNode.
149 * <p>
150 * Current implementation is rather simple and uses hashcode.
151 * </p>
152 *
153 * @param node the DependencyNode to use.
154 * @return the unique id.
155 */
156 private static String generateId( DependencyNode node )
157 {
158 return String.valueOf( node.hashCode() );
159 }
160 }