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1   package org.apache.maven.plugin.checkstyle.rss;
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 org.apache.maven.plugin.MojoExecutionException;
23  import org.apache.maven.plugin.logging.Log;
24  import org.apache.maven.plugin.logging.SystemStreamLog;
25  import org.apache.velocity.context.Context;
26  import org.apache.velocity.exception.ResourceNotFoundException;
27  import org.apache.velocity.exception.VelocityException;
28  import org.codehaus.plexus.velocity.VelocityComponent;
29  
30  import java.io.File;
31  import java.io.FileWriter;
32  import java.io.IOException;
33  import java.io.Writer;
34  
35  /**
36   * <p>
37   * A component to work with VelocityTemplates from within plugins.
38   * </p>
39   *
40   * <p/>
41   * You will need to reference the velocity component as a parameter
42   * in your plugin.  Like this:
43   * </p>
44   * <pre>
45   * /&#042;&#042;
46   *  &#042; Velocity Component
47   *  &#042; &#064;component
48   *  &#042;/
49   *  private VelocityComponent velocity;
50   * </pre>
51   *
52   * @author <a href="mailto:joakim@erdfelt.net">Joakim Erdfelt</a>
53   * @version $Id: VelocityTemplate.html 959038 2015-07-20 17:14:24Z dennisl $
54   */
55  public class VelocityTemplate
56  {
57      private String templateDirectory;
58  
59      private Log log;
60  
61      private VelocityComponent velocity;
62  
63      public VelocityTemplate( VelocityComponent velocityComponent, String templateBaseDirectory )
64      {
65          this.velocity = velocityComponent;
66          this.templateDirectory = templateBaseDirectory;
67      }
68  
69      public String getTemplateDirectory()
70      {
71          return templateDirectory;
72      }
73  
74      public VelocityComponent getVelocity()
75      {
76          return velocity;
77      }
78  
79      /**
80       * Using a specified Velocity Template and provided context, create the outputFilename.
81       *
82       * @param outputFilename the file to be generated.
83       * @param template       the velocity template to use.
84       * @param context        the velocity context map.
85       * @throws VelocityException if the template was not found or any other Velocity exception.
86       * @throws MojoExecutionException
87       * @throws IOException
88       */
89      public void generate( String outputFilename, String template, Context context )
90          throws VelocityException, MojoExecutionException, IOException
91      {
92          Writer writer = null;
93  
94          try
95          {
96              File f = new File( outputFilename );
97  
98              if ( !f.getParentFile().exists() )
99              {
100                 f.getParentFile().mkdirs();
101             }
102 
103             writer = new FileWriter( f );
104 
105             getVelocity().getEngine().mergeTemplate( templateDirectory + "/" + template, context, writer );
106         }
107         catch ( ResourceNotFoundException e )
108         {
109             throw new ResourceNotFoundException( "Template not found: " + templateDirectory + "/" + template, e );
110         }
111         catch ( VelocityException | IOException e )
112         {
113             throw e; // to get past generic catch for Exception.
114         }
115         catch ( Exception e )
116         {
117             throw new MojoExecutionException( e.getMessage(), e );
118         }
119         finally
120         {
121             if ( writer != null )
122             {
123                 writer.flush();
124                 writer.close();
125 
126                 getLog().debug( "File " + outputFilename + " created..." );
127             }
128         }
129     }
130 
131     public void setTemplateDirectory( String templateDirectory )
132     {
133         this.templateDirectory = templateDirectory;
134     }
135 
136     public void setVelocity( VelocityComponent velocity )
137     {
138         this.velocity = velocity;
139     }
140 
141     public Log getLog()
142     {
143         if ( this.log == null )
144         {
145             this.log = new SystemStreamLog();
146         }
147         return log;
148     }
149 
150     public void setLog( Log log )
151     {
152         this.log = log;
153     }
154 
155 }