1 /*
2 * Copyright 2002-2007 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.core.io;
18
19 import java.io.ByteArrayInputStream;
20 import java.io.IOException;
21 import java.io.InputStream;
22 import java.util.Arrays;
23
24 /**
25 * {@link Resource} implementation for a given byte array.
26 * Creates a ByteArrayInputStreams for the given byte array.
27 *
28 * <p>Useful for loading content from any given byte array,
29 * without having to resort to a single-use {@link InputStreamResource}.
30 * Particularly useful for creating mail attachments from local content,
31 * where JavaMail needs to be able to read the stream multiple times.
32 *
33 * @author Juergen Hoeller
34 * @since 1.2.3
35 * @see java.io.ByteArrayInputStream
36 * @see InputStreamResource
37 * @see org.springframework.mail.javamail.MimeMessageHelper#addAttachment(String, InputStreamSource)
38 */
39 public class ByteArrayResource extends AbstractResource {
40
41 private final byte[] byteArray;
42
43 private final String description;
44
45
46 /**
47 * Create a new ByteArrayResource.
48 * @param byteArray the byte array to wrap
49 */
50 public ByteArrayResource(byte[] byteArray) {
51 this(byteArray, "resource loaded from byte array");
52 }
53
54 /**
55 * Create a new ByteArrayResource.
56 * @param byteArray the byte array to wrap
57 * @param description where the byte array comes from
58 */
59 public ByteArrayResource(byte[] byteArray, String description) {
60 if (byteArray == null) {
61 throw new IllegalArgumentException("Byte array must not be null");
62 }
63 this.byteArray = byteArray;
64 this.description = (description != null ? description : "");
65 }
66
67 /**
68 * Return the underlying byte array.
69 */
70 public final byte[] getByteArray() {
71 return this.byteArray;
72 }
73
74
75 /**
76 * This implementation always returns <code>true</code>.
77 */
78 public boolean exists() {
79 return true;
80 }
81
82 /**
83 * This implementation returns a ByteArrayInputStream for the
84 * underlying byte array.
85 * @see java.io.ByteArrayInputStream
86 */
87 public InputStream getInputStream() throws IOException {
88 return new ByteArrayInputStream(this.byteArray);
89 }
90
91 /**
92 * This implementation returns the passed-in description, if any.
93 */
94 public String getDescription() {
95 return this.description;
96 }
97
98
99 /**
100 * This implementation compares the underlying byte array.
101 * @see java.util.Arrays#equals(byte[], byte[])
102 */
103 public boolean equals(Object obj) {
104 return (obj == this ||
105 (obj instanceof ByteArrayResource && Arrays.equals(((ByteArrayResource) obj).byteArray, this.byteArray)));
106 }
107
108 /**
109 * This implementation returns the hash code based on the
110 * underlying byte array.
111 */
112 public int hashCode() {
113 return (byte[].class.hashCode() * 29 * this.byteArray.length);
114 }
115
116 }
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