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.io.input;
18
19 import java.io.Reader;
20 import java.util.Arrays;
21 import java.util.Collections;
22 import java.util.HashSet;
23 import java.util.Set;
24 import java.util.function.IntPredicate;
25
26 /**
27 * A filter reader that removes a given set of characters represented as {@code int} code points, handy to remove known
28 * junk characters from CSV files for example.
29 * <p>
30 * This class must convert each {@code int} read to an {@link Integer}. You can increase the Integer cache with a system
31 * property, see {@link Integer}.
32 * </p>
33 */
34 public class CharacterSetFilterReader extends AbstractCharacterFilterReader {
35
36 private static IntPredicate toIntPredicate(final Set<Integer> skip) {
37 if (skip == null) {
38 return SKIP_NONE;
39 }
40 final Set<Integer> unmodifiableSet = Collections.unmodifiableSet(skip);
41 return c -> unmodifiableSet.contains(Integer.valueOf(c));
42 }
43
44 /**
45 * Constructs a new reader.
46 *
47 * @param reader the reader to filter.
48 * @param skip the set of characters to filter out.
49 * @since 2.9.0
50 */
51 public CharacterSetFilterReader(final Reader reader, final Integer... skip) {
52 this(reader, new HashSet<>(Arrays.asList(skip)));
53 }
54
55 /**
56 * Constructs a new reader.
57 *
58 * @param reader the reader to filter.
59 * @param skip the set of characters to filter out.
60 */
61 public CharacterSetFilterReader(final Reader reader, final Set<Integer> skip) {
62 super(reader, toIntPredicate(skip));
63 }
64
65 }