Mercurial > hg > blitz_condensed
diff src/com/go/trove/io/PositionReader.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/com/go/trove/io/PositionReader.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,135 @@ +/* ==================================================================== + * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group + * ==================================================================== + * The Tea Software License, Version 1.1 + * + * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. The end-user documentation included with the redistribution, + * if any, must include the following acknowledgment: + * "This product includes software developed by the + * Walt Disney Internet Group (http://opensource.go.com/)." + * Alternately, this acknowledgment may appear in the software itself, + * if and wherever such third-party acknowledgments normally appear. + * + * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must + * not be used to endorse or promote products derived from this + * software without prior written permission. For written + * permission, please contact opensource@dig.com. + * + * 5. Products derived from this software may not be called "Tea", + * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", + * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior + * written permission of the Walt Disney Internet Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY + * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * For more information about Tea, please see http://opensource.go.com/. + */ + +package com.go.trove.io; + +import java.io.*; + +/****************************************************************************** + * The PositionReader tracks the postion in the stream of the next character + * to be read. PositionReaders chain together such that the position is + * read from the earliest PositionReader in the chain. + * + * <p>Position readers automatically close the underlying input stream when + * the end of file is reached. Ordinary input streams don't do this. + * + * @author Brian S O'Neill + * @version + * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 12/11/00 <!-- $--> + */ +public class PositionReader extends FilterReader { + /** Is non-null when this PositionReader is chained to another. */ + protected PositionReader mPosReader; + + protected int mPosition = 0; + + private boolean mClosed = false; + + public PositionReader(Reader reader) { + super(reader); + if (reader instanceof PositionReader) { + mPosReader = (PositionReader)reader; + } + } + + /** + * @return the position of the next character to be read. + */ + public int getNextPosition() { + return mPosition; + } + + public int read() throws IOException { + try { + int c; + if ((c = in.read()) != -1) { + if (mPosReader == null) { + mPosition++; + } + else { + mPosition = mPosReader.getNextPosition(); + } + } + else { + close(); + } + + return c; + } + catch (IOException e) { + if (mClosed) { + return -1; + } + else { + throw e; + } + } + } + + public int read(char[] buf, int off, int length) throws IOException { + int i = 0; + while (i < length) { + int c; + if ((c = read()) == -1) { + return (i == 0)? -1 : i; + } + buf[i++ + off] = (char)c; + } + + return i; + } + + public void close() throws IOException { + mClosed = true; + super.close(); + } +}