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.csv;
18
19 import java.io.IOException;
20 import java.io.Reader;
21 import java.io.Writer;
22 import java.nio.Buffer;
23 import java.nio.CharBuffer;
24
25 /** Copied from Apache Commons IO. */
26 final class IOUtils {
27
28 /**
29 * The default buffer size ({@value}).
30 */
31 static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
32
33 /**
34 * Represents the end-of-file (or stream).
35 */
36 private static final int EOF = -1;
37
38 /**
39 * Copies chars from a large (over 2GB) {@code Reader} to an {@code Appendable}.
40 * <p>
41 * This method buffers the input internally, so there is no need to use a
42 * {@code BufferedReader}.
43 * </p>
44 * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
45 *
46 * @param input the {@code Reader} to read from
47 * @param output the {@code Appendable} to append to
48 * @return the number of characters copied
49 * @throws NullPointerException if the input or output is null
50 * @throws IOException if an I/O error occurs
51 * @since 2.7
52 */
53 static long copy(final Reader input, final Appendable output) throws IOException {
54 return copy(input, output, CharBuffer.allocate(DEFAULT_BUFFER_SIZE));
55 }
56
57 /**
58 * Copies chars from a large (over 2GB) {@code Reader} to an {@code Appendable}.
59 * <p>
60 * This method uses the provided buffer, so there is no need to use a
61 * {@code BufferedReader}.
62 * </p>
63 *
64 * @param input the {@code Reader} to read from
65 * @param output the {@code Appendable} to write to
66 * @param buffer the buffer to be used for the copy
67 * @return the number of characters copied
68 * @throws NullPointerException if the input or output is null
69 * @throws IOException if an I/O error occurs
70 * @since 2.7
71 */
72 static long copy(final Reader input, final Appendable output, final CharBuffer buffer) throws IOException {
73 long count = 0;
74 int n;
75 while (EOF != (n = input.read(buffer))) {
76 ((Buffer) buffer).flip();
77 output.append(buffer, 0, n);
78 count += n;
79 }
80 return count;
81 }
82
83 /**
84 * Copies chars from a large (over 2GB) {@code Reader} to a {@code Writer}.
85 * <p>
86 * This method buffers the input internally, so there is no need to use a
87 * {@code BufferedReader}.
88 * </p>
89 * <p>
90 * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
91 * </p>
92 *
93 * @param input the {@code Reader} to read from
94 * @param output the {@code Writer} to write to
95 * @return the number of characters copied
96 * @throws NullPointerException if the input or output is null
97 * @throws IOException if an I/O error occurs
98 * @since 1.3
99 */
100 static long copyLarge(final Reader input, final Writer output) throws IOException {
101 return copyLarge(input, output, new char[DEFAULT_BUFFER_SIZE]);
102 }
103
104 /**
105 * Copies chars from a large (over 2GB) {@code Reader} to a {@code Writer}.
106 * <p>
107 * This method uses the provided buffer, so there is no need to use a
108 * {@code BufferedReader}.
109 * </p>
110 *
111 * @param input the {@code Reader} to read from
112 * @param output the {@code Writer} to write to
113 * @param buffer the buffer to be used for the copy
114 * @return the number of characters copied
115 * @throws NullPointerException if the input or output is null
116 * @throws IOException if an I/O error occurs
117 * @since 2.2
118 */
119 static long copyLarge(final Reader input, final Writer output, final char[] buffer) throws IOException {
120 long count = 0;
121 int n;
122 while (EOF != (n = input.read(buffer))) {
123 output.write(buffer, 0, n);
124 count += n;
125 }
126 return count;
127 }
128
129 /**
130 * Throws the given throwable.
131 *
132 * @param <T> The throwable cast type.
133 * @param throwable The throwable to rethrow.
134 * @return nothing because we throw.
135 * @throws T Always thrown.
136 */
137 @SuppressWarnings("unchecked")
138 static <T extends Throwable> RuntimeException rethrow(final Throwable throwable) throws T {
139 throw (T) throwable;
140 }
141
142 /** No instances. */
143 private IOUtils() {
144 // Noop
145 }
146
147 }