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 * https://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 final class HeaderHtmlVelocityDelegate {
34
35 /**
36 * A builder class for instantiation of the {@link HeaderHtmlVelocityDelegate}.
37 */
38 public static final class HeaderHtmlVelocityDelegateBuilder {
39
40 /**
41 * Private constructor so that we can have a proper builder pattern.
42 */
43 private HeaderHtmlVelocityDelegateBuilder() {
44 }
45
46 /**
47 * Builds up the {@link ReadmeHtmlVelocityDelegate} from the previously set parameters.
48 *
49 * @return a new {@link ReadmeHtmlVelocityDelegate}.
50 */
51 public HeaderHtmlVelocityDelegate build() {
52 return new HeaderHtmlVelocityDelegate();
53 }
54 }
55
56 /** The location of the velocity template for this class. */
57 private static final String TEMPLATE = "resources/org/apache/commons/release/plugin/velocity/HEADER.vm";
58
59 /**
60 * For instantiating our {@link HeaderHtmlVelocityDelegate} using the {@link HeaderHtmlVelocityDelegateBuilder}.
61 *
62 * @return a {@link HeaderHtmlVelocityDelegateBuilder}.
63 */
64 public static HeaderHtmlVelocityDelegateBuilder builder() {
65 return new HeaderHtmlVelocityDelegateBuilder();
66 }
67
68 /** The private constructor to be used by the {@link HeaderHtmlVelocityDelegateBuilder}. */
69 private HeaderHtmlVelocityDelegate() {
70 }
71
72 /**
73 * Builds the HEADER.vm velocity template to the writer passed in.
74 *
75 * @param writer any {@link Writer} that we wish to have the filled velocity template written to.
76 * @return the {@link Writer} that we've filled out the template into.
77 */
78 public Writer render(final Writer writer) {
79 final VelocityEngine ve = new VelocityEngine();
80 ve.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
81 ve.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
82 ve.init();
83 final Template template = ve.getTemplate(TEMPLATE);
84 final VelocityContext context = new VelocityContext();
85 template.merge(context, writer);
86 return writer;
87 }
88 }