Java tutorial
/****************************************************************
* 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. *
****************************************************************/
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* Adds extra dot if dot occurs in message body at beginning of line (according to RFC1939)
* Compare also org.apache.james.smtpserver.SMTPInputStream
*/
public class ExtraDotOutputStream extends FilterOutputStream {
/*
static public void main(String[] args) throws IOException
{
String data = ".This is a test\r\nof the thing.\r\nWe should not have much trouble.\r\n.doubled?\r\nor not?\n.doubled\nor not?\r\n\r\n\n\n\r\r\r\n";
OutputStream os = new ExtraDotOutputStream(System.out);
os.write(data.getBytes());
}
*/
/**
* Counter for number of last (0A or 0D).
*/
protected int countLast0A0D;
/**
* Constructor that wraps an OutputStream.
*
* @param out the OutputStream to be wrapped
*/
public ExtraDotOutputStream(OutputStream out) {
super(out);
countLast0A0D = 2; // we already assume a CRLF at beginning (otherwise TOP would not work correctly !)
}
/**
* Writes a byte to the stream, adding dots where appropriate.
* Also 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 '.':
if (countLast0A0D == 2) {
// add extra dot (the first of the pair)
out.write('.');
}
countLast0A0D = 0;
break;
case '\r':
if (countLast0A0D == 1) out.write('\n'); // two CR in a row, so insert an LF first
countLast0A0D = 1;
break;
case '\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.
*/
if (countLast0A0D != 1) out.write('\r');
countLast0A0D = 2;
break;
default:
// we're no longer at the start of a line
countLast0A0D = 0;
break;
}
out.write(b);
}
/**
* Ensure that the stream is CRLF terminated.
*
* @throws IOException if an error occurs writing the byte
*/
public void checkCRLFTerminator() throws IOException {
if (countLast0A0D != 2) {
write('\n');
}
}
}
//////////////////////////////
/****************************************************************
* 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. *
****************************************************************/
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import junit.framework.TestCase;
/**
* Tests for the ExtraDotOutputStream
*/
public class ExtraDotOutputStreamTest extends TestCase {
public void testMain() throws IOException {
String data = ".This is a test\r\nof the thing.\r\nWe should not have much trouble.\r\n.doubled?\r\nor not?\n.doubled\nor not?\r\n\r\n\n\n\r\r\r\n";
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
OutputStream os = new ExtraDotOutputStream(bOut);
os.write(data.getBytes());
os.flush();
String expected = "..This is a test\r\nof the thing.\r\nWe should not have much trouble.\r\n..doubled?\r\nor not?\r\n..doubled\r\nor not?\r\n\r\n\r\n\r\n\r\n\r\n\r\n";
assertEquals(expected, bOut.toString());
}
/*
* Test method for 'org.apache.james.util.ExtraDotOutputStream.checkCRLFTerminator()'
*/
public void testCheckCRLFTerminator() throws IOException {
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
ExtraDotOutputStream os = new ExtraDotOutputStream(bOut);
// if the stream is empty then we should not add the CRLF.
os.checkCRLFTerminator();
os.flush();
assertEquals("", bOut.toString());
os.write("Test".getBytes());
os.flush();
assertEquals("Test", bOut.toString());
os.checkCRLFTerminator();
os.flush();
assertEquals("Test\r\n", bOut.toString());
// if the stream ends with \r we should simply add the \n
os.write("A line with incomplete ending\r".getBytes());
os.flush();
assertEquals("Test\r\nA line with incomplete ending\r", bOut.toString());
os.checkCRLFTerminator();
os.flush();
assertEquals("Test\r\nA line with incomplete ending\r\n", bOut.toString());
// already correctly terminated, should leave the output untouched
os.checkCRLFTerminator();
os.flush();
assertEquals("Test\r\nA line with incomplete ending\r\n", bOut.toString());
}
}