1 package org.apache.maven.plugin.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 *
32 * http://en.wikipedia.org/wiki/Trivial_Graph_Format
33 *
34 * @author <a href="mailto:jerome.creignou@gmail.com">Jerome Creignou</a>
35 * @since 2.1
36 */
37 public class TGFDependencyNodeVisitor
38 extends AbstractSerializingVisitor
39 implements DependencyNodeVisitor
40 {
41
42 /**
43 * Utiity class to write an Edge.
44 *
45 * @author <a href="mailto:jerome.creignou@gmail.com">Jerome Creignou</a>
46 */
47 static final class EdgeAppender
48 {
49 /**
50 * Edge start.
51 */
52 private DependencyNode from;
53
54 /**
55 * Edge end.
56 */
57 private DependencyNode to;
58
59 /**
60 * Edge label. (optional)
61 */
62 private String label;
63
64 /**
65 * Build a new EdgeAppender.
66 *
67 * @param from edge start.
68 * @param to edge end
69 * @param label optional label.
70 */
71 public EdgeAppender( DependencyNode from, DependencyNode to, String label )
72 {
73 super();
74 this.from = from;
75 this.to = to;
76 this.label = label;
77 }
78
79 /**
80 * build a string representing the edge.
81 */
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 public boolean endVisit( DependencyNode node )
114 {
115 if ( node.getParent() == null || node.getParent() == node )
116 {
117 // dump edges on last node endVisit
118 writer.println( "#" );
119 for ( EdgeAppender edge : edges )
120 {
121 writer.println( edge.toString() );
122 }
123 }
124 else
125 {
126 DependencyNode p = node.getParent();
127 // using scope as edge label.
128 edges.add( new EdgeAppender( p, node, node.getArtifact().getScope() ) );
129 }
130 return true;
131 }
132
133 /**
134 * {@inheritDoc}
135 */
136 public boolean visit( DependencyNode node )
137 {
138 // write node
139 writer.write( generateId( node ) );
140 writer.write( " " );
141 writer.println( node.toNodeString() );
142 return true;
143 }
144
145 /**
146 * Generate a unique id from a DependencyNode.
147 * <p>
148 * Current implementation is rather simple and uses hashcode.
149 * </p>
150 *
151 * @param node the DependencyNode to use.
152 * @return the unique id.
153 */
154 private static String generateId( DependencyNode node )
155 {
156 return String.valueOf( node.hashCode() );
157 }
158 }