Java/File Input Output/FilterOutputStream
Adds extra dot if dot occurs in message body at beginning of line (according to RFC1939)
<source lang="java">
/****************************************************************
* 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());
}
}
</source>
Capture System.out into a JFrame
<source lang="java">
import java.io.ByteArrayOutputStream; import java.io.FileWriter; import java.io.FilterOutputStream; import java.io.IOException; import java.io.OutputStream; import java.io.PrintStream; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTextArea; public class Main extends JFrame {
JTextArea aTextArea = new JTextArea();
PrintStream aPrintStream = new PrintStream(new FilteredStream(new ByteArrayOutputStream()));
public Main() {
setSize(300, 300);
add("Center", new JScrollPane(aTextArea));
setVisible(true);
System.setOut(aPrintStream); // catches System.out messages
System.setErr(aPrintStream); // catches error messages
}
class FilteredStream extends FilterOutputStream {
public FilteredStream(OutputStream aStream) {
super(aStream);
}
public void write(byte b[]) throws IOException {
String aString = new String(b);
aTextArea.append(aString);
}
public void write(byte b[], int off, int len) throws IOException {
String aString = new String(b, off, len);
aTextArea.append(aString);
FileWriter aWriter = new FileWriter("a.log", true);
aWriter.write(aString);
aWriter.close();
}
}
}
</source>
