| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.commons.net.telnet; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| |
| /** |
| * Wraps an output stream. |
| * <p> |
| * In binary mode, the only conversion is to double IAC. |
| * <p> |
| * In ASCII mode, if convertCRtoCRLF is true (currently always true), any CR is converted to CRLF. |
| * IACs are doubled. |
| * Also a bare LF is converted to CRLF and a bare CR is converted to CR\0 |
| * <p> |
| */ |
| |
| |
| final class TelnetOutputStream extends OutputStream |
| { |
| private final TelnetClient client; |
| // TODO there does not appear to be any way to change this value - should it be a ctor parameter? |
| private final boolean convertCRtoCRLF = true; |
| private boolean lastWasCR; |
| |
| TelnetOutputStream(final TelnetClient client) |
| { |
| this.client = client; |
| } |
| |
| |
| /** Closes the stream. */ |
| @Override |
| public void close() throws IOException |
| { |
| client.closeOutputStream(); |
| } |
| |
| |
| /** Flushes the stream. */ |
| @Override |
| public void flush() throws IOException |
| { |
| client.flushOutputStream(); |
| } |
| |
| |
| /** |
| * Writes a byte array to the stream. |
| * <p> |
| * @param buffer The byte array to write. |
| * @throws IOException If an error occurs while writing to the underlying |
| * stream. |
| */ |
| @Override |
| public void write(final byte buffer[]) throws IOException |
| { |
| write(buffer, 0, buffer.length); |
| } |
| |
| /** |
| * Writes a number of bytes from a byte array to the stream starting from |
| * a given offset. |
| * <p> |
| * @param buffer The byte array to write. |
| * @param offset The offset into the array at which to start copying data. |
| * @param length The number of bytes to write. |
| * @throws IOException If an error occurs while writing to the underlying |
| * stream. |
| */ |
| @Override |
| public void write(final byte buffer[], int offset, int length) throws IOException |
| { |
| synchronized (client) |
| { |
| while (length-- > 0) { |
| write(buffer[offset++]); |
| } |
| } |
| } |
| |
| /** |
| * Writes a byte to the stream. |
| * <p> |
| * @param ch The byte to write. |
| * @throws IOException If an error occurs while writing to the underlying |
| * stream. |
| */ |
| @Override |
| public void write(int ch) throws IOException |
| { |
| |
| synchronized (client) |
| { |
| ch &= 0xff; |
| |
| if (client.requestedWont(TelnetOption.BINARY)) // i.e. ASCII |
| { |
| if (lastWasCR) |
| { |
| if (convertCRtoCRLF) |
| { |
| client.sendByte('\n'); |
| if (ch == '\n') // i.e. was CRLF anyway |
| { |
| lastWasCR = false; |
| return ; |
| } |
| } // __convertCRtoCRLF |
| else if (ch != '\n') |
| { |
| client.sendByte('\0'); // RFC854 requires CR NUL for bare CR |
| } |
| } |
| |
| switch (ch) |
| { |
| case '\r': |
| client.sendByte('\r'); |
| lastWasCR = true; |
| break; |
| case '\n': |
| if (!lastWasCR) { // convert LF to CRLF |
| client.sendByte('\r'); |
| } |
| client.sendByte(ch); |
| lastWasCR = false; |
| break; |
| case TelnetCommand.IAC: |
| client.sendByte(TelnetCommand.IAC); |
| client.sendByte(TelnetCommand.IAC); |
| lastWasCR = false; |
| break; |
| default: |
| client.sendByte(ch); |
| lastWasCR = false; |
| break; |
| } |
| } // end ASCII |
| else if (ch == TelnetCommand.IAC) |
| { |
| client.sendByte(ch); |
| client.sendByte(TelnetCommand.IAC); |
| } else { |
| client.sendByte(ch); |
| } |
| } |
| } |
| } |