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.input;
19
20 import java.io.FilterReader;
21 import java.io.IOException;
22 import java.io.Reader;
23
24 /**
25 * Reader that limits the number of characters read in a chunk of the specified size or less.
26 */
27 public class ChunkedReader extends FilterReader {
28
29 private final int chunkSize;
30
31 public ChunkedReader(final Reader reader, final int chunkSize) {
32 super(reader);
33 if (chunkSize <= 0) {
34 throw new IllegalArgumentException("chunkSize must be > 0");
35 }
36 this.chunkSize = chunkSize;
37 }
38
39 @Override
40 public void close() throws IOException {
41 // nothing to do.
42 }
43
44 @Override
45 public int read(final char[] cbuf, final int off, final int len) throws IOException {
46 return super.read(cbuf, off, len > chunkSize ? chunkSize : len);
47 }
48
49 }