188 lines
6.6 KiB
Java
188 lines
6.6 KiB
Java
/* StringBufferInputStream.java -- Read an String as a stream
|
|
Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.io;
|
|
|
|
/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
|
|
* "The Java Language Specification", ISBN 0-201-63451-1
|
|
* plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
|
|
* Status: Believed complete and correct. Deprecated in JDK 1.1.
|
|
*/
|
|
|
|
/**
|
|
* This class permits a <code>String</code> to be read as an input stream.
|
|
* The low eight bits of each character in the <code>String</code> are the
|
|
* bytes that are returned. The high eight bits of each character are
|
|
* discarded.
|
|
* <p>
|
|
* The mark/reset functionality in this class behaves differently than
|
|
* normal. The <code>mark()</code> method is always ignored and the
|
|
* <code>reset()</code> method always resets in stream to start reading from
|
|
* position 0 in the String. Note that since this method does not override
|
|
* <code>markSupported()</code> in <code>InputStream</code>, calling that
|
|
* method will return <code>false</code>.
|
|
* <p>
|
|
* Note that this class is deprecated because it does not properly handle
|
|
* 16-bit Java characters. It is provided for backwards compatibility only
|
|
* and should not be used for new development. The <code>StringReader</code>
|
|
* class should be used instead.
|
|
*
|
|
* @deprecated
|
|
*
|
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
|
* @author Warren Levy <warrenl@cygnus.com>
|
|
*/
|
|
public class StringBufferInputStream extends InputStream
|
|
{
|
|
/** The String which is the input to this stream. */
|
|
protected String buffer;
|
|
|
|
/** Position of the next byte in buffer to be read. */
|
|
protected int pos = 0;
|
|
|
|
/** The length of the String buffer. */
|
|
protected int count;
|
|
|
|
/**
|
|
* Create a new <code>StringBufferInputStream</code> that will read bytes
|
|
* from the passed in <code>String</code>. This stream will read from the
|
|
* beginning to the end of the <code>String</code>.
|
|
*
|
|
* @param s The <code>String</code> this stream will read from.
|
|
*/
|
|
public StringBufferInputStream(String s)
|
|
{
|
|
buffer = s;
|
|
count = s.length();
|
|
}
|
|
|
|
/**
|
|
* This method returns the number of bytes available to be read from this
|
|
* stream. The value returned will be equal to <code>count - pos</code>.
|
|
*
|
|
* @return The number of bytes that can be read from this stream before
|
|
* blocking, which is all of them
|
|
*/
|
|
public int available()
|
|
{
|
|
return count - pos;
|
|
}
|
|
|
|
/**
|
|
* This method reads one byte from the stream. The <code>pos</code> counter
|
|
* is advanced to the next byte to be read. The byte read is returned as
|
|
* an int in the range of 0-255. If the stream position is already at the
|
|
* end of the buffer, no byte is read and a -1 is returned in order to
|
|
* indicate the end of the stream.
|
|
*
|
|
* @return The byte read, or -1 if end of stream
|
|
*/
|
|
public int read()
|
|
{
|
|
if (pos >= count)
|
|
return -1; // EOF
|
|
|
|
return ((int) buffer.charAt(pos++)) & 0xFF;
|
|
}
|
|
|
|
/**
|
|
* This method reads bytes from the stream and stores them into a caller
|
|
* supplied buffer. It starts storing the data at index <code>offset</code>
|
|
* into the buffer and attempts to read <code>len</code> bytes. This method
|
|
* can return before reading the number of bytes requested if the end of the
|
|
* stream is encountered first. The actual number of bytes read is
|
|
* returned. If no bytes can be read because the stream is already at
|
|
* the end of stream position, a -1 is returned.
|
|
* <p>
|
|
* This method does not block.
|
|
*
|
|
* @param b The array into which the bytes read should be stored.
|
|
* @param off The offset into the array to start storing bytes
|
|
* @param len The requested number of bytes to read
|
|
*
|
|
* @return The actual number of bytes read, or -1 if end of stream.
|
|
*/
|
|
public int read(byte[] b, int off, int len)
|
|
{
|
|
if (off < 0 || len < 0 || off + len > b.length)
|
|
throw new ArrayIndexOutOfBoundsException();
|
|
|
|
if (pos >= count)
|
|
return -1; // EOF
|
|
|
|
int numRead = Math.min(len, count - pos);
|
|
if (numRead < 0)
|
|
return 0;
|
|
|
|
buffer.getBytes(pos, pos + numRead, b, off);
|
|
pos += numRead;
|
|
return numRead;
|
|
}
|
|
|
|
/**
|
|
* This method sets the read position in the stream to the beginning
|
|
* setting the <code>pos</code> variable equal to 0. Note that this differs
|
|
* from the common implementation of the <code>reset()</code> method.
|
|
*/
|
|
public void reset()
|
|
{
|
|
pos = 0;
|
|
}
|
|
|
|
/**
|
|
* This method attempts to skip the requested number of bytes in the
|
|
* input stream. It does this by advancing the <code>pos</code> value by the
|
|
* specified number of bytes. It this would exceed the length of the
|
|
* buffer, then only enough bytes are skipped to position the stream at
|
|
* the end of the buffer. The actual number of bytes skipped is returned.
|
|
*
|
|
* @param n The requested number of bytes to skip
|
|
*
|
|
* @return The actual number of bytes skipped.
|
|
*/
|
|
public long skip(long n)
|
|
{
|
|
if (n < 0)
|
|
return 0L;
|
|
|
|
long actualSkip = Math.min(n, count - pos);
|
|
pos += actualSkip;
|
|
return actualSkip;
|
|
}
|
|
}
|