com.sun.mail.smtp.SMTPOutputStream Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.mail.smtp;
import java.io.*;
import com.sun.mail.util.CRLFOutputStream;
/**
* In addition to converting lines into the canonical format,
* i.e., terminating lines with the CRLF sequence, escapes the "."
* by adding another "." to any "." that appears in the beginning
* of a line. See RFC821 section 4.5.2.
*
* @author Max Spivak
* @see CRLFOutputStream
*/
public class SMTPOutputStream extends CRLFOutputStream {
public SMTPOutputStream(OutputStream os) {
super(os);
}
@Override
public void write(int b) throws IOException {
// if that last character was a newline, and the current
// character is ".", we always write out an extra ".".
if ((lastb == '\n' || lastb == '\r' || lastb == -1) && b == '.') {
out.write('.');
}
super.write(b);
}
/*
* This method has been added to improve performance.
*/
@Override
public void write(byte b[], int off, int len) throws IOException {
int lastc = (lastb == -1) ? '\n' : lastb;
int start = off;
len += off;
for (int i = off; i < len; i++) {
if ((lastc == '\n' || lastc == '\r') && b[i] == '.') {
super.write(b, start, i - start);
out.write('.');
start = i;
}
lastc = b[i];
}
if ((len - start) > 0)
super.write(b, start, len - start);
}
/**
* Override flush method in FilterOutputStream.
*
* The MimeMessage writeTo method flushes its buffer at the end,
* but we don't want to flush data out to the socket until we've
* also written the terminating "\r\n.\r\n".
*
* We buffer nothing so there's nothing to flush. We depend
* on the fact that CRLFOutputStream also buffers nothing.
* SMTPTransport will manually flush the socket before reading
* the response.
*/
@Override
public void flush() {
// do nothing
}
/**
* Ensure we're at the beginning of a line.
* Write CRLF if not.
*
* @exception IOException if the write fails
*/
public void ensureAtBOL() throws IOException {
if (!atBOL)
super.writeln();
}
}