| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.io.input; |
| |
| import static org.apache.commons.io.IOUtils.EOF; |
| |
| import java.io.FilterReader; |
| import java.io.IOException; |
| import java.io.Reader; |
| import java.util.function.IntPredicate; |
| |
| /** |
| * A filter reader that filters out characters where subclasses decide which characters to filter out. |
| */ |
| public abstract class AbstractCharacterFilterReader extends FilterReader { |
| |
| private static final IntPredicate SKIP_NONE = ch -> false; |
| |
| private final IntPredicate skip; |
| |
| /** |
| * Constructs a new reader. |
| * |
| * @param reader the reader to filter |
| */ |
| protected AbstractCharacterFilterReader(final Reader reader) { |
| this(reader, SKIP_NONE); |
| } |
| |
| /** |
| * Constructs a new reader. |
| * |
| * @param reader the reader to filter. |
| * @param skip Skip test. |
| * @since 2.9.0 |
| */ |
| protected AbstractCharacterFilterReader(final Reader reader, final IntPredicate skip) { |
| super(reader); |
| this.skip = skip == null ? SKIP_NONE : skip; |
| } |
| |
| /** |
| * Returns true if the given character should be filtered out, false to keep the character. |
| * |
| * @param ch the character to test. |
| * @return true if the given character should be filtered out, false to keep the character. |
| */ |
| protected boolean filter(final int ch) { |
| return skip.test(ch); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| int ch; |
| do { |
| ch = in.read(); |
| } while (ch != EOF && filter(ch)); |
| return ch; |
| } |
| |
| @Override |
| public int read(final char[] cbuf, final int off, final int len) throws IOException { |
| final int read = super.read(cbuf, off, len); |
| if (read == EOF) { |
| return EOF; |
| } |
| int pos = off - 1; |
| for (int readPos = off; readPos < off + read; readPos++) { |
| if (filter(cbuf[readPos])) { |
| continue; |
| } |
| pos++; |
| if (pos < readPos) { |
| cbuf[pos] = cbuf[readPos]; |
| } |
| } |
| return pos - off + 1; |
| } |
| } |