/* SocketInputStream.java -- An InputStream for Sockets Copyright (C) 1998, 2000, 2002 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 gnu.java.net; import java.io.InputStream; import java.io.IOException; /** * This class contains an implementation of InputStream for * sockets. It in an internal only class used by PlainSocketImpl. * * @author Aaron M. Renn (arenn@urbanophile.com) */ class SocketInputStream extends InputStream { /*************************************************************************/ /* * Instance Variables */ /** * The PlainSocketImpl object this stream is associated with */ private PlainSocketImpl impl; /*************************************************************************/ /* * Constructors */ /** * Builds an instance of this class from a PlainSocketImpl object */ protected SocketInputStream(PlainSocketImpl impl) { this.impl = impl; } /*************************************************************************/ /* * Instance Methods */ /** * Returns the number of bytes available to be read before blocking */ public int available() throws IOException { return(impl.available()); } /*************************************************************************/ /** * Determines if "mark" functionality is supported on this stream. For * sockets, this is always false. Note that the superclass default is * false, but it is overridden out of safety concerns and/or paranoia. */ public boolean markSupported() { return(false); } /*************************************************************************/ /** * Do nothing mark method since we don't support this functionality. Again, * overriding out of paranoia. * * @param readlimit In theory, the number of bytes we can read before the mark becomes invalid */ public void mark(int readlimit) { } /*************************************************************************/ /** * Since we don't support mark, this method always throws an exception * * @exception IOException Everytime since we don't support this functionality */ public void reset() throws IOException { throw new IOException("Socket InputStreams do not support mark/reset"); } /*************************************************************************/ /** * This method not only closes the stream, it closes the underlying socket * (and thus any connection) and invalidates any other Input/Output streams * for the underlying impl object */ public void close() throws IOException { impl.close(); } /*************************************************************************/ /** * Reads the next byte of data and returns it as an int. * * @return The byte read (as an int) or -1 if end of stream); * * @exception IOException If an error occurs. */ public int read() throws IOException { byte buf[] = new byte[1]; int bytes_read = read(buf, 0, buf.length); if (bytes_read != -1) return(buf[0] & 0xFF); else return(-1); } /*************************************************************************/ /** * Reads up to buf.length bytes of data into the caller supplied buffer. * * @return The actual number of bytes read or -1 if end of stream * * @exception IOException If an error occurs. */ public int read(byte[] buf) throws IOException { return(read(buf, 0, buf.length)); } /*************************************************************************/ /** * Reads up to len bytes of data into the caller supplied buffer starting * at offset bytes from the start of the buffer * * @return The number of bytes actually read or -1 if end of stream * * @exception IOException If an error occurs. */ public int read(byte[] buf, int offset, int len) throws IOException { int bytes_read = impl.read(buf, offset, len); if (bytes_read == 0) return(-1); return(bytes_read); } } // class SocketInputStream