+++ /dev/null
-/* SequenceInputStream.java -- Reads multiple input streams in sequence
- 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;
-
-import java.util.Enumeration;
-
-/* 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.
- */
-
-/**
- * This class merges a sequence of multiple <code>InputStream</code>'s in
- * order to form a single logical stream that can be read by applications
- * that expect only one stream.
- * <p>
- * The streams passed to the constructor method are read in order until
- * they return -1 to indicate they are at end of stream. When a stream
- * reports end of stream, it is closed, then the next stream is read.
- * When the last stream is closed, the next attempt to read from this
- * stream will return a -1 to indicate it is at end of stream.
- * <p>
- * If this stream is closed prior to all subordinate streams being read
- * to completion, all subordinate streams are closed.
- *
- * @author Aaron M. Renn (arenn@urbanophile.com)
- * @author Warren Levy <warrenl@cygnus.com>
- */
-public class SequenceInputStream extends InputStream
-{
- /** The handle for the current input stream. */
- private InputStream in;
-
- /** Secondary input stream; not used if constructed w/ enumeration. */
- private InputStream in2;
-
- /** The enum handle; not used if constructed w/ 2 explicit input streams. */
- private Enumeration enum;
-
- /**
- * This method creates a new <code>SequenceInputStream</code> that obtains
- * its list of subordinate <code>InputStream</code>s from the specified
- * <code>Enumeration</code>
- *
- * @param e An <code>Enumeration</code> that will return a list of
- * <code>InputStream</code>s to read in sequence
- */
- public SequenceInputStream(Enumeration e)
- {
- enum = e;
- in = (InputStream) enum.nextElement();
- in2 = null;
- }
-
- /**
- * This method creates a new <code>SequenceInputStream</code> that will read
- * the two specified subordinate <code>InputStream</code>s in sequence.
- *
- * @param s1 The first <code>InputStream</code> to read
- * @param s2 The second <code>InputStream</code> to read
- */
- public SequenceInputStream(InputStream s1, InputStream s2)
- {
- in = s1;
- in2 = s2;
- }
-
- /**
- * This method returns the number of bytes than can be read from the
- * currently being read subordinate stream before that stream could
- * block. Note that it is possible more bytes than this can actually
- * be read without the stream blocking. If a 0 is returned, then the
- * stream could block on the very next read.
- *
- * @return The number of bytes that can be read before blocking could occur
- *
- * @exception IOException If an error occurs
- */
- public int available() throws IOException
- {
- if (in == null)
- return 0;
-
- return in.available();
- }
-
- /**
- * Closes this stream. This will cause any remaining unclosed subordinate
- * <code>InputStream</code>'s to be closed as well. Subsequent attempts to
- * read from this stream may cause an exception.
- *
- * @exception IOException If an error occurs
- */
- public void close() throws IOException
- {
- while (in != null)
- {
- in.close();
- in = getNextStream ();
- }
- }
-
- /**
- * This method reads an unsigned byte from the input stream and returns it
- * as an int in the range of 0-255. This method also will return -1 if
- * the end of the stream has been reached. This will only happen when
- * all of the subordinate streams have been read.
- * <p>
- * This method will block until the byte can be read.
- *
- * @return The byte read, or -1 if end of stream
- *
- * @exception IOException If an error occurs
- */
- public int read() throws IOException
- {
- int ch = -1;
-
- while (in != null && (ch = in.read()) < 0)
- {
- in.close();
- in = getNextStream();
- }
-
- return ch;
- }
-
- /**
- * This method reads bytes from a 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. The actual number
- * of bytes read is returned as an int. A -1 is returend to indicate the
- * end of the stream. This will only happen when all of the subordinate
- * streams have been read.
- * <p>
- * This method will block until at least one byte can be read.
- *
- * @param b The array into which 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
- *
- * @exception IOException If an error occurs
- */
- public int read(byte[] b, int off, int len) throws IOException
- {
- int ch = -1;
-
- // The validity of the parameters will be checked by in.read so
- // don't bother doing it here.
- while (in != null && (ch = in.read(b, off, len)) < 0)
- {
- in.close();
- in = getNextStream();
- }
-
- return ch;
- }
-
- /**
- * This private method is used to get the next <code>InputStream</code> to
- * read from. Returns null when no more streams are available.
- */
- private InputStream getNextStream()
- {
- InputStream nextIn = null;
-
- if (enum != null)
- {
- if (enum.hasMoreElements())
- nextIn = (InputStream) enum.nextElement();
- }
- else
- if (in2 != null)
- {
- nextIn = in2;
- in2 = null;
- }
-
- return nextIn;
- }
-}
projects / msp430-gcc.git / blobdiff