1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.shiro.lang.util;
20
21 import java.io.File;
22 import java.io.InputStream;
23
24 /**
25 * A {@code ByteSource} wraps a byte array and provides additional encoding operations. Most users will find the
26 * {@link Util} inner class sufficient to construct ByteSource instances.
27 *
28 * @since 1.0
29 */
30 public interface ByteSource {
31
32 /**
33 * Returns the wrapped byte array.
34 *
35 * @return the wrapped byte array.
36 */
37 byte[] getBytes();
38
39 /**
40 * Returns the <a href="http://en.wikipedia.org/wiki/Hexadecimal">Hex</a>-formatted String representation of the
41 * underlying wrapped byte array.
42 *
43 * @return the <a href="http://en.wikipedia.org/wiki/Hexadecimal">Hex</a>-formatted String representation of the
44 * underlying wrapped byte array.
45 */
46 String toHex();
47
48 /**
49 * Returns the <a href="http://en.wikipedia.org/wiki/Base64">Base 64</a>-formatted String representation of the
50 * underlying wrapped byte array.
51 *
52 * @return the <a href="http://en.wikipedia.org/wiki/Base64">Base 64</a>-formatted String representation of the
53 * underlying wrapped byte array.
54 */
55 String toBase64();
56
57 /**
58 * Returns {@code true} if the underlying wrapped byte array is null or empty (zero length), {@code false}
59 * otherwise.
60 *
61 * @return {@code true} if the underlying wrapped byte array is null or empty (zero length), {@code false}
62 * otherwise.
63 * @since 1.2
64 */
65 boolean isEmpty();
66
67 /**
68 * Utility class that can construct ByteSource instances. This is slightly nicer than needing to know the
69 * {@code ByteSource} implementation class to use.
70 *
71 * @since 1.2
72 */
73 final class Util {
74
75 private Util() {
76 }
77
78 /**
79 * Returns a new {@code ByteSource} instance representing the specified byte array.
80 *
81 * @param bytes the bytes to represent as a {@code ByteSource} instance.
82 * @return a new {@code ByteSource} instance representing the specified byte array.
83 */
84 public static ByteSource bytes(byte[] bytes) {
85 return new SimpleByteSource(bytes);
86 }
87
88 /**
89 * Returns a new {@code ByteSource} instance representing the specified character array's bytes. The byte
90 * array is obtained assuming {@code UTF-8} encoding.
91 *
92 * @param chars the character array to represent as a {@code ByteSource} instance.
93 * @return a new {@code ByteSource} instance representing the specified character array's bytes.
94 */
95 public static ByteSource bytes(char[] chars) {
96 return new SimpleByteSource(chars);
97 }
98
99 /**
100 * Returns a new {@code ByteSource} instance representing the specified string's bytes. The byte
101 * array is obtained assuming {@code UTF-8} encoding.
102 *
103 * @param string the string to represent as a {@code ByteSource} instance.
104 * @return a new {@code ByteSource} instance representing the specified string's bytes.
105 */
106 public static ByteSource bytes(String string) {
107 return new SimpleByteSource(string);
108 }
109
110 /**
111 * Returns a new {@code ByteSource} instance representing the specified ByteSource.
112 *
113 * @param source the ByteSource to represent as a new {@code ByteSource} instance.
114 * @return a new {@code ByteSource} instance representing the specified ByteSource.
115 */
116 public static ByteSource bytes(ByteSource source) {
117 return new SimpleByteSource(source);
118 }
119
120 /**
121 * Returns a new {@code ByteSource} instance representing the specified File's bytes.
122 *
123 * @param file the file to represent as a {@code ByteSource} instance.
124 * @return a new {@code ByteSource} instance representing the specified File's bytes.
125 */
126 public static ByteSource bytes(File file) {
127 return new SimpleByteSource(file);
128 }
129
130 /**
131 * Returns a new {@code ByteSource} instance representing the specified InputStream's bytes.
132 *
133 * @param stream the InputStream to represent as a {@code ByteSource} instance.
134 * @return a new {@code ByteSource} instance representing the specified InputStream's bytes.
135 */
136 public static ByteSource bytes(InputStream stream) {
137 return new SimpleByteSource(stream);
138 }
139
140 /**
141 * Returns {@code true} if the specified object can be easily represented as a {@code ByteSource} using
142 * the {@link ByteSource.Util}'s default heuristics, {@code false} otherwise.
143 * <p/>
144 * This implementation merely returns {@link SimpleByteSource}
145 * .{@link SimpleByteSource#isCompatible(Object) isCompatible(source)}.
146 *
147 * @param source the object to test to see if it can be easily converted to ByteSource instances using default
148 * heuristics.
149 * @return {@code true} if the specified object can be easily represented as a {@code ByteSource} using
150 * the {@link ByteSource.Util}'s default heuristics, {@code false} otherwise.
151 */
152 public static boolean isCompatible(Object source) {
153 return SimpleByteSource.isCompatible(source);
154 }
155
156 /**
157 * Returns a {@code ByteSource} instance representing the specified byte source argument. If the argument
158 * <em>cannot</em> be easily converted to bytes (as is indicated by the {@link #isCompatible(Object)} JavaDoc),
159 * this method will throw an {@link IllegalArgumentException}.
160 *
161 * @param source the byte-backed instance that should be represented as a {@code ByteSource} instance.
162 * @return a {@code ByteSource} instance representing the specified byte source argument.
163 * @throws IllegalArgumentException if the argument <em>cannot</em> be easily converted to bytes
164 * (as indicated by the {@link #isCompatible(Object)} JavaDoc)
165 */
166 public static ByteSource bytes(Object source) throws IllegalArgumentException {
167 if (source == null) {
168 return null;
169 }
170 if (!isCompatible(source)) {
171 String msg = "Unable to heuristically acquire bytes for object of type ["
172 + source.getClass().getName() + "]. If this type is indeed a byte-backed data type, you might "
173 + "want to write your own ByteSource implementation to extract its bytes explicitly.";
174 throw new IllegalArgumentException(msg);
175 }
176 if (source instanceof byte[]) {
177 return bytes((byte[]) source);
178 } else if (source instanceof ByteSource) {
179 return (ByteSource) source;
180 } else if (source instanceof char[]) {
181 return bytes((char[]) source);
182 } else if (source instanceof String) {
183 return bytes((String) source);
184 } else if (source instanceof File) {
185 return bytes((File) source);
186 } else if (source instanceof InputStream) {
187 return bytes((InputStream) source);
188 } else {
189 throw new IllegalStateException("Encountered unexpected byte source. This is a bug - please notify "
190 + "the Shiro developer list asap (the isCompatible implementation does not reflect this "
191 + "method's implementation).");
192 }
193 }
194 }
195 }