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 * https://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
18 package org.apache.commons.io.output;
19
20 import java.io.FilterWriter;
21 import java.io.IOException;
22 import java.io.Writer;
23
24 import org.apache.commons.io.IOUtils;
25
26 /**
27 * Writer which breaks larger output blocks into chunks. Native code may need to copy the input array; if the write buffer is very large this can cause OOME.
28 *
29 * @since 2.5
30 */
31 public class ChunkedWriter extends FilterWriter {
32
33 /**
34 * The default chunk size to use: {@value} bytes.
35 */
36 private static final int DEFAULT_CHUNK_SIZE = IOUtils.DEFAULT_BUFFER_SIZE;
37
38 /**
39 * The maximum chunk size to us when writing data arrays.
40 */
41 private final int chunkSize;
42
43 /**
44 * Constructs a new writer that uses a chunk size of {@link #DEFAULT_CHUNK_SIZE}
45 *
46 * @param writer the writer to wrap.
47 */
48 public ChunkedWriter(final Writer writer) {
49 this(writer, DEFAULT_CHUNK_SIZE);
50 }
51
52 /**
53 * Constructs a new writer that uses the specified chunk size.
54 *
55 * @param writer the writer to wrap.
56 * @param chunkSize the chunk size to use; must be a positive number.
57 * @throws IllegalArgumentException if the chunk size is <= 0.
58 */
59 public ChunkedWriter(final Writer writer, final int chunkSize) {
60 super(writer);
61 if (chunkSize <= 0) {
62 throw new IllegalArgumentException();
63 }
64 this.chunkSize = chunkSize;
65 }
66
67 /**
68 * Writes the data buffer in chunks to the underlying writer.
69 *
70 * @param data The data.
71 * @param srcOffset the offset.
72 * @param length the number of bytes to write.
73 * @throws NullPointerException if the data is {@code null}.
74 * @throws IndexOutOfBoundsException if {@code srcOffset} or {@code length} are negative,
75 * or if {@code srcOffset + length} is greater than {@code data.length}.
76 * @throws IOException If an I/O error occurs.
77 */
78 @Override
79 public void write(final char[] data, final int srcOffset, final int length) throws IOException {
80 IOUtils.checkFromIndexSize(data, srcOffset, length);
81 int bytes = length;
82 int dstOffset = srcOffset;
83 while (bytes > 0) {
84 final int chunk = Math.min(bytes, chunkSize);
85 out.write(data, dstOffset, chunk);
86 bytes -= chunk;
87 dstOffset += chunk;
88 }
89 }
90 }