001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.parser;
014
015import java.io.*;
016
017/**
018 * Input stream meant to be used as input for stream-based parsers.
019 *
020 * <p>
021 * Keeps track of current byte position.
022 *
023 * <h5 class='section'>Notes:</h5><ul>
024 *    <li class='warn'>This class is not thread safe.
025 * </ul>
026 *
027 * <h5 class='section'>See Also:</h5><ul>
028 *    <li class='link'><a class="doclink" href="../../../../index.html#jm.SerializersAndParsers">Serializers and Parsers</a>
029 * </ul>
030 */
031public class ParserInputStream extends InputStream implements Positionable {
032
033   private final InputStream is;
034   int pos = 0;
035
036   /**
037    * Constructor.
038    *
039    * @param pipe The parser input.
040    * @throws IOException Thrown by underlying stream.
041    */
042   protected ParserInputStream(ParserPipe pipe) throws IOException {
043      this.is = pipe.getInputStream();
044      pipe.setPositionable(this);
045   }
046
047   @Override /* InputStream */
048   public int read() throws IOException {
049      int i = is.read();
050      if (i > 0)
051         pos++;
052      return i;
053   }
054
055   @Override /* Positionable */
056   public Position getPosition() {
057      return new Position(pos);
058   }
059}