package com.sun.org.apache.regexp.internal;
/*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. 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 acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Jakarta-Regexp", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache 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 APACHE SOFTWARE FOUNDATION 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* .
*
*/
import java.io.InputStream;
import java.io.IOException;
/** Encapsulates InputStream, ...
*
* @author Ales Novak
*/
public final class StreamCharacterIterator implements CharacterIterator
{
/** Underlying is */
private final InputStream is;
/** Buffer of read chars */
private final StringBuffer buff;
/** read end? */
private boolean closed;
/** @param is an InputStream, which is parsed */
public StreamCharacterIterator(InputStream is)
{
this.is = is;
this.buff = new StringBuffer(512);
this.closed = false;
}
/** @return a substring */
public String substring(int offset, int length)
{
try
{
ensure(offset + length);
return buff.toString().substring(offset, length);
}
catch (IOException e)
{
throw new StringIndexOutOfBoundsException(e.getMessage());
}
}
/** @return a substring */
public String substring(int offset)
{
try
{
readAll();
return buff.toString().substring(offset);
}
catch (IOException e)
{
throw new StringIndexOutOfBoundsException(e.getMessage());
}
}
/** @return a character at the specified position. */
public char charAt(int pos)
{
try
{
ensure(pos);
return buff.charAt(pos);
}
catch (IOException e)
{
throw new StringIndexOutOfBoundsException(e.getMessage());
}
}
/** @return true iff if the specified index is after the end of the character stream */
public boolean isEnd(int pos)
{
if (buff.length() > pos)
{
return false;
}
else
{
try
{
ensure(pos);
return (buff.length() <= pos);
}
catch (IOException e)
{
throw new StringIndexOutOfBoundsException(e.getMessage());
}
}
}
/** Reads n characters from the stream and appends them to the buffer */
private int read(int n) throws IOException
{
if (closed)
{
return 0;
}
int c;
int i = n;
while (--i >= 0)
{
c = is.read();
if (c < 0) // EOF
{
closed = true;
break;
}
buff.append((char) c);
}
return n - i;
}
/** Reads rest of the stream. */
private void readAll() throws IOException
{
while(! closed)
{
read(1000);
}
}
/** Reads chars up to the idx */
private void ensure(int idx) throws IOException
{
if (closed)
{
return;
}
if (idx < buff.length())
{
return;
}
read(idx + 1 - buff.length());
}
}