Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
RepeatingInputStream |
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| 1.8888888888888888;1.889 | ||||
RepeatingInputStream$1 |
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| 1.8888888888888888;1.889 | ||||
RepeatingInputStream$LimitedOutput |
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| 1.8888888888888888;1.889 | ||||
RepeatingInputStream$RepeatArray |
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| 1.8888888888888888;1.889 | ||||
RepeatingInputStream$RepeatOneByte |
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| 1.8888888888888888;1.889 |
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.flatfile.util; | |
18 | ||
19 | import java.io.IOException; | |
20 | import java.io.InputStream; | |
21 | ||
22 | import org.apache.commons.lang3.Validate; | |
23 | ||
24 | /** | |
25 | * Provides factory methods to return InputStreams that return a repeating | |
26 | * ordered sequence of bytes, optionally limiting output to some maximum total | |
27 | * size. | |
28 | * | |
29 | * @version $Revision: 1301242 $ $Date: 2009-03-24 16:09:19 -0500 (Tue, 24 Mar | |
30 | * 2009) $ | |
31 | */ | |
32 | public abstract class RepeatingInputStream { | |
33 | 0 | /** |
34 | 0 | * Construct a new {@link RepeatingInputStream} instance. |
35 | */ | |
36 | 0 | private RepeatingInputStream() { |
37 | 0 | } |
38 | ||
39 | 18 | /** |
40 | * An InputStream that repeats a single byte forever. | |
41 | */ | |
42 | 9 | private static class RepeatOneByte extends InputStream { |
43 | private final byte b; | |
44 | ||
45 | /** | |
46 | * Create a new RepeatOneByte instance. | |
47 | * | |
48 | 18 | * @param b byte to repeat |
49 | 18 | */ |
50 | 81 | private RepeatOneByte(byte b) { |
51 | 36 | this.b = b; |
52 | 36 | } |
53 | ||
54 | /** | |
55 | * {@inheritDoc} | |
56 | 1354 | */ |
57 | public int read() throws IOException { | |
58 | 2708 | return b; |
59 | } | |
60 | } | |
61 | ||
62 | /** | |
63 | 0 | * An InputStream that repeats a byte[] forever. |
64 | */ | |
65 | 0 | private static class RepeatArray extends InputStream { |
66 | private final byte[] b; | |
67 | private int pos; | |
68 | ||
69 | /** | |
70 | * Create a new RepeatArray instance. | |
71 | * | |
72 | * @param b byte[] to repeat | |
73 | 0 | */ |
74 | 0 | private RepeatArray(byte[] b) { |
75 | 0 | this.b = b; |
76 | 0 | } |
77 | ||
78 | /** | |
79 | * {@inheritDoc} | |
80 | */ | |
81 | public synchronized int read() throws IOException { | |
82 | 0 | try { |
83 | 0 | return b[pos++]; |
84 | 0 | } finally { |
85 | 0 | if (pos == b.length) { |
86 | 0 | pos = 0; |
87 | } | |
88 | 0 | } |
89 | } | |
90 | } | |
91 | ||
92 | /** | |
93 | * InputStream that limits the content of another InputStream. | |
94 | 42 | */ |
95 | 21 | private static class LimitedOutput extends InputStream { |
96 | private static final int EOF = -1; | |
97 | ||
98 | private final InputStream source; | |
99 | private final int bytesToReturn; | |
100 | private int bytesReturned; | |
101 | ||
102 | /** | |
103 | * Create a new LimitedOutput instance. | |
104 | * | |
105 | * @param source wrapped InputStream | |
106 | * @param bytesToReturn int max | |
107 | */ | |
108 | 147 | private LimitedOutput(InputStream source, int bytesToReturn) { |
109 | 126 | this.source = source; |
110 | 126 | this.bytesToReturn = bytesToReturn; |
111 | 126 | } |
112 | 42 | |
113 | /** | |
114 | * {@inheritDoc} | |
115 | */ | |
116 | public int read() throws IOException { | |
117 | 220 | if (bytesReturned == bytesToReturn) { |
118 | 162 | return EOF; |
119 | 26 | } |
120 | try { | |
121 | 294 | return source.read(); |
122 | 84 | } finally { |
123 | 168 | bytesReturned++; |
124 | 84 | } |
125 | } | |
126 | } | |
127 | ||
128 | /** | |
129 | * Holds cached instances of single-byte RepeatingInputStreams, with enough | |
130 | * space for every unique byte value. | |
131 | */ | |
132 | 4 | private static final InputStream[] REPEAT_BYTE = new InputStream[(int) Math.pow(2, Byte.SIZE)]; |
133 | 2 | |
134 | /** | |
135 | * Get an InputStream that will return the specified byte[] forever. | |
136 | * | |
137 | * @param b byte[] to repeat | |
138 | * @return {@link InputStream} | |
139 | * @throws NullPointerException if {@code b} is {@code null} | |
140 | */ | |
141 | public static InputStream of(byte... b) { | |
142 | 136 | Validate.notNull(b); |
143 | 136 | if (b.length == 1) { |
144 | 136 | final int index = 0 | b[0]; |
145 | 136 | InputStream result = REPEAT_BYTE[index]; |
146 | 204 | if (result == null) { |
147 | 104 | result = new RepeatOneByte(b[0]); |
148 | 104 | REPEAT_BYTE[index] = result; |
149 | 68 | } |
150 | 204 | return result; |
151 | 18 | } |
152 | 18 | return new RepeatArray(b); |
153 | } | |
154 | 68 | |
155 | /** | |
156 | 0 | * Get an InputStream that will return the specified byte sequence until a |
157 | * total of {@code limit} bytes have been returned. | |
158 | * | |
159 | * @param limit int | |
160 | * @param b byte[] to repeat | |
161 | * @return {@link InputStream} | |
162 | * @throws NullPointerException if {@code b} is {@code null} | |
163 | */ | |
164 | public static synchronized InputStream withLimit(int limit, byte... b) { | |
165 | 84 | return new LimitedOutput(of(b), limit); |
166 | } | |
167 | ||
168 | } |