| /**************************************************************** |
| * 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.james.jdkim.mailets; |
| |
| import java.io.FilterOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| |
| /** |
| * A Filter for use with SMTP or other protocols in which lines must end with |
| * CRLF. Converts every "isolated" occourency of \r or \n with \r\n |
| * |
| * RFC 2821 #2.3.7 mandates that line termination is CRLF, and that CR and LF |
| * must not be transmitted except in that pairing. If we get a naked LF, convert |
| * to CRLF. |
| * |
| */ |
| public class CRLFOutputStream extends FilterOutputStream { |
| |
| /** |
| * Counter for number of last (0A or 0D). |
| */ |
| protected int statusLast; |
| |
| protected final static int LAST_WAS_OTHER = 0; |
| |
| protected final static int LAST_WAS_CR = 1; |
| |
| protected final static int LAST_WAS_LF = 2; |
| |
| protected boolean startOfLine = true; |
| |
| /** |
| * Constructor that wraps an OutputStream. |
| * |
| * @param out |
| * the OutputStream to be wrapped |
| */ |
| public CRLFOutputStream(OutputStream out) { |
| super(out); |
| statusLast = LAST_WAS_LF; // we already assume a CRLF at beginning |
| // (otherwise TOP would not work correctly |
| // !) |
| } |
| |
| /** |
| * Writes a byte to the stream Fixes any naked CR or LF to the RFC 2821 |
| * mandated CFLF pairing. |
| * |
| * @param b |
| * the byte to write |
| * |
| * @throws IOException |
| * if an error occurs writing the byte |
| */ |
| public void write(int b) throws IOException { |
| switch (b) { |
| case '\r': |
| out.write('\r'); |
| out.write('\n'); |
| startOfLine = true; |
| statusLast = LAST_WAS_CR; |
| break; |
| case '\n': |
| if (statusLast != LAST_WAS_CR) { |
| out.write('\r'); |
| out.write('\n'); |
| startOfLine = true; |
| } |
| statusLast = LAST_WAS_LF; |
| break; |
| default: |
| // we're no longer at the start of a line |
| out.write(b); |
| startOfLine = false; |
| statusLast = LAST_WAS_OTHER; |
| break; |
| } |
| } |
| |
| /** |
| * Provides an extension point for ExtraDotOutputStream to be able to add |
| * dots at the beginning of new lines. |
| * |
| * @see java.io.FilterOutputStream#write(byte[], int, int) |
| */ |
| protected void writeChunk(byte buffer[], int offset, int length) |
| throws IOException { |
| out.write(buffer, offset, length); |
| } |
| |
| /** |
| * @see java.io.FilterOutputStream#write(byte[], int, int) |
| */ |
| public synchronized void write(byte buffer[], int offset, int length) |
| throws IOException { |
| /* optimized */ |
| int lineStart = offset; |
| for (int i = offset; i < length + offset; i++) { |
| switch (buffer[i]) { |
| case '\r': |
| // CR case. Write down the last line |
| // and position the new lineStart at the next char |
| writeChunk(buffer, lineStart, i - lineStart); |
| out.write('\r'); |
| out.write('\n'); |
| startOfLine = true; |
| lineStart = i + 1; |
| statusLast = LAST_WAS_CR; |
| break; |
| case '\n': |
| if (statusLast != LAST_WAS_CR) { |
| writeChunk(buffer, lineStart, i - lineStart); |
| out.write('\r'); |
| out.write('\n'); |
| startOfLine = true; |
| } |
| lineStart = i + 1; |
| statusLast = LAST_WAS_LF; |
| break; |
| default: |
| statusLast = LAST_WAS_OTHER; |
| } |
| } |
| if (length + offset > lineStart) { |
| writeChunk(buffer, lineStart, length + offset - lineStart); |
| startOfLine = false; |
| } |
| } |
| |
| /** |
| * Ensure that the stream is CRLF terminated. |
| * |
| * @throws IOException |
| * if an error occurs writing the byte |
| */ |
| public void checkCRLFTerminator() throws IOException { |
| if (statusLast == LAST_WAS_OTHER) { |
| out.write('\r'); |
| out.write('\n'); |
| statusLast = LAST_WAS_CR; |
| } |
| } |
| } |