001/****************************************************************
002 * Licensed to the Apache Software Foundation (ASF) under one   *
003 * or more contributor license agreements.  See the NOTICE file *
004 * distributed with this work for additional information        *
005 * regarding copyright ownership.  The ASF licenses this file   *
006 * to you under the Apache License, Version 2.0 (the            *
007 * "License"); you may not use this file except in compliance   *
008 * with the License.  You may obtain a copy of the License at   *
009 *                                                              *
010 *   http://www.apache.org/licenses/LICENSE-2.0                 *
011 *                                                              *
012 * Unless required by applicable law or agreed to in writing,   *
013 * software distributed under the License is distributed on an  *
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
015 * KIND, either express or implied.  See the License for the    *
016 * specific language governing permissions and limitations      *
017 * under the License.                                           *
018 ****************************************************************/
019
020package org.apache.james.mpt.helper;
021
022import java.io.IOException;
023import java.io.InputStream;
024import java.nio.ByteBuffer;
025import java.nio.CharBuffer;
026import java.nio.charset.Charset;
027import java.nio.charset.CharsetEncoder;
028
029
030public class ByteBufferInputStream extends InputStream {
031    private final ByteBuffer buffer = ByteBuffer.allocate(160384);
032
033    private final CharsetEncoder encoder = Charset.forName("ASCII").newEncoder();
034
035    private boolean readLast = true;
036
037    public int read() throws IOException {
038        if (!readLast) {
039            readLast = true;
040            buffer.flip();
041        }
042        int result = -1;
043        if (buffer.hasRemaining()) {
044            result = buffer.get();
045        }
046        return result;
047    }
048
049    public void nextLine(String line) {
050        if (buffer.position() > 0 && readLast) {
051            buffer.compact();
052        }
053        encoder.encode(CharBuffer.wrap(line), buffer, true);
054        buffer.put((byte) '\r');
055        buffer.put((byte) '\n');
056        readLast = false;
057    }
058}