--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/net/TelnetInputStream.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,151 @@
+/*
+ * Copyright 1994-1995 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.net;
+
+import java.io.*;
+
+/**
+ * This class provides input and output streams for telnet clients.
+ * This class overrides read to do CRLF processing as specified in
+ * RFC 854. The class assumes it is running on a system where lines
+ * are terminated with a single newline <LF> character.
+ *
+ * This is the relevant section of RFC 824 regarding CRLF processing:
+ *
+ * <pre>
+ * The sequence "CR LF", as defined, will cause the NVT to be
+ * positioned at the left margin of the next print line (as would,
+ * for example, the sequence "LF CR"). However, many systems and
+ * terminals do not treat CR and LF independently, and will have to
+ * go to some effort to simulate their effect. (For example, some
+ * terminals do not have a CR independent of the LF, but on such
+ * terminals it may be possible to simulate a CR by backspacing.)
+ * Therefore, the sequence "CR LF" must be treated as a single "new
+ * line" character and used whenever their combined action is
+ * intended; the sequence "CR NUL" must be used where a carriage
+ * return alone is actually desired; and the CR character must be
+ * avoided in other contexts. This rule gives assurance to systems
+ * which must decide whether to perform a "new line" function or a
+ * multiple-backspace that the TELNET stream contains a character
+ * following a CR that will allow a rational decision.
+ *
+ * Note that "CR LF" or "CR NUL" is required in both directions
+ * (in the default ASCII mode), to preserve the symmetry of the
+ * NVT model. Even though it may be known in some situations
+ * (e.g., with remote echo and suppress go ahead options in
+ * effect) that characters are not being sent to an actual
+ * printer, nonetheless, for the sake of consistency, the protocol
+ * requires that a NUL be inserted following a CR not followed by
+ * a LF in the data stream. The converse of this is that a NUL
+ * received in the data stream after a CR (in the absence of
+ * options negotiations which explicitly specify otherwise) should
+ * be stripped out prior to applying the NVT to local character
+ * set mapping.
+ * </pre>
+ *
+ * @author Jonathan Payne
+ */
+
+public class TelnetInputStream extends FilterInputStream {
+ /** If stickyCRLF is true, then we're a machine, like an IBM PC,
+ where a Newline is a CR followed by LF. On UNIX, this is false
+ because Newline is represented with just a LF character. */
+ boolean stickyCRLF = false;
+ boolean seenCR = false;
+
+ public boolean binaryMode = false;
+
+ public TelnetInputStream(InputStream fd, boolean binary) {
+ super(fd);
+ binaryMode = binary;
+ }
+
+ public void setStickyCRLF(boolean on) {
+ stickyCRLF = on;
+ }
+
+ public int read() throws IOException {
+ if (binaryMode)
+ return super.read();
+
+ int c;
+
+ /* If last time we determined we saw a CRLF pair, and we're
+ not turning that into just a Newline (that is, we're
+ stickyCRLF), then return the LF part of that sticky
+ pair now. */
+
+ if (seenCR) {
+ seenCR = false;
+ return '\n';
+ }
+
+ if ((c = super.read()) == '\r') { /* CR */
+ switch (c = super.read()) {
+ default:
+ case -1: /* this is an error */
+ throw new TelnetProtocolException("misplaced CR in input");
+
+ case 0: /* NUL - treat CR as CR */
+ return '\r';
+
+ case '\n': /* CRLF - treat as NL */
+ if (stickyCRLF) {
+ seenCR = true;
+ return '\r';
+ } else {
+ return '\n';
+ }
+ }
+ }
+ return c;
+ }
+
+ /** read into a byte array */
+ public int read(byte bytes[]) throws IOException {
+ return read(bytes, 0, bytes.length);
+ }
+
+ /**
+ * Read into a byte array at offset <i>off</i> for length <i>length</i>
+ * bytes.
+ */
+ public int read(byte bytes[], int off, int length) throws IOException {
+ if (binaryMode)
+ return super.read(bytes, off, length);
+
+ int c;
+ int offStart = off;
+
+ while (--length >= 0) {
+ c = read();
+ if (c == -1)
+ break;
+ bytes[off++] = (byte)c;
+ }
+ return (off > offStart) ? off - offStart : -1;
+ }
+}