1 /**
2 * This file Copyright (c) 2015-2016 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.resourceloader;
35
36 import info.magnolia.resourceloader.util.ResourceTreeWalker;
37
38 import java.io.BufferedReader;
39 import java.io.IOException;
40 import java.io.InputStream;
41 import java.io.InputStreamReader;
42 import java.io.Reader;
43 import java.nio.charset.Charset;
44 import java.util.List;
45
46 /**
47 * Exposes methods that {@link AbstractResource} simply delegates to. Consequently, one only has to implement and
48 * test AbstractResourceOrigin's methods, while navigation still happens naturally through the Resource methods.
49 * AbstractResource implementations are merely vehicles for the underlying resource.
50 *
51 * @param <P> Subclasses of AbstractResourceOrigin are expected to produce {@link Resource} instances which are subclasses of {@link AbstractResource}.
52 */
53 public abstract class AbstractResourceOrigin<P extends AbstractResource> implements ResourceOrigin<P> {
54 private final String name;
55
56 protected AbstractResourceOrigin(String name) {
57 this.name = name;
58 }
59
60 @Override
61 public String getName() {
62 return name;
63 }
64
65 @Override
66 public void traverseWith(ResourceVisitor visitor) {
67 new ResourceTreeWalker(visitor).traverse(getRoot());
68 }
69
70 /**
71 * @see Resource#isFile()
72 */
73 protected abstract boolean isFile(P resource);
74
75 /**
76 * @see Resource#isDirectory()
77 */
78 protected abstract boolean isDirectory(P resource);
79
80 /**
81 * @see Resource#isEditable()
82 */
83 protected boolean isEditable(P resource) {
84 return false;
85 }
86
87 /**
88 * @see Resource#getPath()
89 */
90 protected abstract String getPath(P resource);
91
92 /**
93 * @see Resource#getName()
94 */
95 protected abstract String getName(P resource);
96
97 /**
98 * @see Resource#getLastModified()
99 */
100 protected abstract long getLastModified(P resource);
101
102 /**
103 * @see Resource#listChildren()
104 */
105 protected abstract List<P> listChildren(P resource);
106
107 /**
108 * @see Resource#getParent()
109 */
110 protected abstract P getParent(P resource);
111
112 /**
113 * @see Resource#openStream()
114 */
115 protected InputStream openStream(P resource) throws IOException {
116 if (resource.isDirectory()) {
117 throw new IllegalStateException("Can not open stream on directory " + resource);
118 }
119 final InputStream inputStream = doOpenStream(resource);
120 if (inputStream == null) {
121 throw new IllegalStateException("InputStream is null for " + resource);
122 }
123 return inputStream;
124 }
125
126 protected abstract InputStream doOpenStream(P resource) throws IOException;
127
128 /**
129 * @see Resource#openReader()
130 */
131 protected Reader openReader(P resource) throws IOException {
132 final InputStream in = openStream(resource);
133 final Charset charset = getCharsetFor(resource);
134 final Reader reader = new InputStreamReader(in, charset);
135 return new BufferedReader(reader);
136 }
137
138 /**
139 * Returns the preferred {@link Charset} to read the given {@link Resource}.
140 */
141 protected abstract Charset getCharsetFor(P resource);
142
143 }