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.mail2.javax.resolver;
18
19 import java.io.IOException;
20 import java.io.InputStream;
21 import java.net.MalformedURLException;
22 import java.net.URL;
23
24 import javax.activation.DataSource;
25 import javax.activation.URLDataSource;
26
27 import org.apache.commons.mail2.core.EmailUtils;
28
29 /**
30 * Creates a {@code DataSource} based on an URL.
31 *
32 * @since 1.3
33 */
34 public class DataSourceUrlResolver extends DataSourceBaseResolver {
35
36 /** The base url of the resource when resolving relative paths */
37 private final URL baseUrl;
38
39 /**
40 * Constructs a new instance.
41 *
42 * @param baseUrl the base URL used for resolving relative resource locations
43 */
44 public DataSourceUrlResolver(final URL baseUrl) {
45 this.baseUrl = baseUrl;
46 }
47
48 /**
49 * Constructs a new instance.
50 *
51 * @param baseUrl the base URL used for resolving relative resource locations
52 * @param lenient shall we ignore resources not found or complain with an exception
53 */
54 public DataSourceUrlResolver(final URL baseUrl, final boolean lenient) {
55 super(lenient);
56 this.baseUrl = baseUrl;
57 }
58
59 /**
60 * Create an URL based on a base URL and a resource location suitable for loading the resource.
61 *
62 * @param resourceLocation a resource location
63 * @return the corresponding URL
64 * @throws java.net.MalformedURLException creating the URL failed
65 */
66 protected URL createUrl(final String resourceLocation) throws MalformedURLException {
67 // if we get an non-existing base url than the resource can
68 // be directly used to create an URL
69 if (baseUrl == null) {
70 return new URL(resourceLocation);
71 }
72 // if we get an non-existing location what we shall do?
73 if (EmailUtils.isEmpty(resourceLocation)) {
74 throw new IllegalArgumentException("No resource defined");
75 }
76 // if we get a stand-alone resource than ignore the base url
77 if (isFileUrl(resourceLocation) || isHttpUrl(resourceLocation)) {
78 return new URL(resourceLocation);
79 }
80 return new URL(getBaseUrl(), resourceLocation.replace("&", "&"));
81 }
82
83 /**
84 * Gets the base URL used for resolving relative resource locations.
85 *
86 * @return the baseUrl
87 */
88 public URL getBaseUrl() {
89 return baseUrl;
90 }
91
92 /** {@inheritDoc} */
93 @Override
94 public DataSource resolve(final String resourceLocation) throws IOException {
95 return resolve(resourceLocation, isLenient());
96 }
97
98 /** {@inheritDoc} */
99 @Override
100 public DataSource resolve(final String resourceLocation, final boolean isLenient) throws IOException {
101 DataSource result = null;
102 try {
103 if (!isCid(resourceLocation)) {
104 result = new URLDataSource(createUrl(resourceLocation));
105 // validate we can read.
106 try (InputStream inputStream = result.getInputStream()) {
107 inputStream.read();
108 }
109 }
110 return result;
111 } catch (final IOException e) {
112 if (isLenient) {
113 return null;
114 }
115 throw e;
116 }
117 }
118 }