1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.release.plugin.velocity;
18
19 import java.io.Writer;
20
21 import org.apache.velocity.Template;
22 import org.apache.velocity.VelocityContext;
23 import org.apache.velocity.app.VelocityEngine;
24 import org.apache.velocity.runtime.RuntimeConstants;
25 import org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader;
26
27 /**
28 * This class' purpose is to generate the <code>HEADER.html</code> that moves along with the
29 * release for the sake of downloading the release from the distribution area.
30 *
31 * @since 1.3
32 */
33 public class HeaderHtmlVelocityDelegate {
34
35 /** The location of the velocity template for this class. */
36 private static final String TEMPLATE = "resources/org/apache/commons/release/plugin/velocity/HEADER.vm";
37
38 /** The private constructor to be used by the {@link HeaderHtmlVelocityDelegateBuilder}. */
39 private HeaderHtmlVelocityDelegate() {
40 }
41
42 /**
43 * For instantiating our {@link HeaderHtmlVelocityDelegate} using the {@link HeaderHtmlVelocityDelegateBuilder}.
44 *
45 * @return a {@link HeaderHtmlVelocityDelegateBuilder}.
46 */
47 public static HeaderHtmlVelocityDelegateBuilder builder() {
48 return new HeaderHtmlVelocityDelegateBuilder();
49 }
50
51 /**
52 * Builds the HEADER.vm velocity template to the writer passed in.
53 *
54 * @param writer any {@link Writer} that we wish to have the filled velocity template written to.
55 * @return the {@link Writer} that we've filled out the template into.
56 */
57 public Writer render(final Writer writer) {
58 final VelocityEngine ve = new VelocityEngine();
59 ve.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
60 ve.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
61 ve.init();
62 final Template template = ve.getTemplate(TEMPLATE);
63 final VelocityContext context = new VelocityContext();
64 template.merge(context, writer);
65 return writer;
66 }
67
68 /**
69 * A builder class for instantiation of the {@link HeaderHtmlVelocityDelegate}.
70 */
71 public static class HeaderHtmlVelocityDelegateBuilder {
72
73 /**
74 * Private constructor so that we can have a proper builder pattern.
75 */
76 private HeaderHtmlVelocityDelegateBuilder() {
77 }
78
79 /**
80 * Builds up the {@link ReadmeHtmlVelocityDelegate} from the previously set parameters.
81 * @return a new {@link ReadmeHtmlVelocityDelegate}.
82 */
83 public HeaderHtmlVelocityDelegate build() {
84 return new HeaderHtmlVelocityDelegate();
85 }
86 }
87 }