org.apache.commons.net.smtp.SMTP Maven / Gradle / Ivy
/*
* 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.smtp;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import org.apache.commons.net.MalformedServerReplyException;
import org.apache.commons.net.ProtocolCommandSupport;
import org.apache.commons.net.SocketClient;
import org.apache.commons.net.io.CRLFLineReader;
import org.apache.commons.net.util.NetConstants;
/**
* SMTP provides the basic the functionality necessary to implement your
* own SMTP client. To derive the full benefits of the SMTP class requires
* some knowledge of the FTP protocol defined in RFC 821. However, there
* is no reason why you should have to use the SMTP class. The
* {@link org.apache.commons.net.smtp.SMTPClient} class,
* derived from SMTP,
* implements all the functionality required of an SMTP client. The
* SMTP class is made public to provide access to various SMTP constants
* and to make it easier for adventurous programmers (or those with
* special needs) to interact with the SMTP protocol and implement their
* own clients. A set of methods with names corresponding to the SMTP
* command names are provided to facilitate this interaction.
*
* You should keep in mind that the SMTP server may choose to prematurely
* close a connection for various reasons. The SMTP class will detect a
* premature SMTP server connection closing when it receives a
* {@link org.apache.commons.net.smtp.SMTPReply#SERVICE_NOT_AVAILABLE SMTPReply.SERVICE_NOT_AVAILABLE }
* response to a command.
* When that occurs, the SMTP class method encountering that reply will throw
* an {@link org.apache.commons.net.smtp.SMTPConnectionClosedException}
* .
* SMTPConectionClosedException
* is a subclass of IOException
and therefore need not be
* caught separately, but if you are going to catch it separately, its
* catch block must appear before the more general IOException
* catch block. When you encounter an
* {@link org.apache.commons.net.smtp.SMTPConnectionClosedException}
* , you must disconnect the connection with
* {@link org.apache.commons.net.SocketClient#disconnect disconnect() }
* to properly clean up the system resources used by SMTP. Before
* disconnecting, you may check the
* last reply code and text with
* {@link #getReplyCode getReplyCode },
* {@link #getReplyString getReplyString },
* and {@link #getReplyStrings getReplyStrings}.
*
* Rather than list it separately for each method, we mention here that
* every method communicating with the server and throwing an IOException
* can also throw a
* {@link org.apache.commons.net.MalformedServerReplyException}
* , which is a subclass
* of IOException. A MalformedServerReplyException will be thrown when
* the reply received from the server deviates enough from the protocol
* specification that it cannot be interpreted in a useful manner despite
* attempts to be as lenient as possible.
*
* @see SMTPClient
* @see SMTPConnectionClosedException
* @see org.apache.commons.net.MalformedServerReplyException
*/
public class SMTP extends SocketClient
{
/** The default SMTP port (25). */
public static final int DEFAULT_PORT = 25;
// We have to ensure that the protocol communication is in ASCII
// but we use ISO-8859-1 just in case 8-bit characters cross
// the wire.
private static final String DEFAULT_ENCODING = "ISO-8859-1";
/**
* The encoding to use (user-settable).
*
* @since 3.1 (changed from private to protected)
*/
protected final String encoding;
/**
* A ProtocolCommandSupport object used to manage the registering of
* ProtocolCommandListeners and te firing of ProtocolCommandEvents.
*/
protected ProtocolCommandSupport _commandSupport_;
BufferedReader reader;
BufferedWriter writer;
private int replyCode;
private final ArrayList replyLines;
private boolean newReplyString;
private String replyString;
/**
* The default SMTP constructor. Sets the default port to
* DEFAULT_PORT
and initializes internal data structures
* for saving SMTP reply information.
*/
public SMTP()
{
this(DEFAULT_ENCODING);
}
/**
* Overloaded constructor where the user may specify a default encoding.
* @param encoding the encoing to use
* @since 2.0
*/
public SMTP(final String encoding) {
setDefaultPort(DEFAULT_PORT);
replyLines = new ArrayList<>();
newReplyString = false;
replyString = null;
_commandSupport_ = new ProtocolCommandSupport(this);
this.encoding = encoding;
}
/**
* Send a command to the server. May also be used to send text data.
*
* @param command the command to send (as a plain String)
* @param args the command arguments, may be {@code null}
* @param includeSpace if {@code true}, add a space between the command and its arguments
* @return the reply code
* @throws IOException
*/
private int sendCommand(final String command, final String args, final boolean includeSpace)
throws IOException
{
final StringBuilder __commandBuffer = new StringBuilder();
__commandBuffer.append(command);
if (args != null)
{
if (includeSpace) {
__commandBuffer.append(' ');
}
__commandBuffer.append(args);
}
__commandBuffer.append(SocketClient.NETASCII_EOL);
final String message = __commandBuffer.toString();
writer.write(message);
writer.flush();
fireCommandSent(command, message);
return getReply();
}
/**
*
* @param command the command to send (as an int defined in {@link SMPTCommand})
* @param args the command arguments, may be {@code null}
* @param includeSpace if {@code true}, add a space between the command and its arguments
* @return the reply code
* @throws IOException
*/
private int sendCommand(final int command, final String args, final boolean includeSpace)
throws IOException
{
return sendCommand(SMTPCommand.getCommand(command), args, includeSpace);
}
/** Initiates control connections and gets initial reply. */
@Override
protected void _connectAction_() throws IOException
{
super._connectAction_();
reader =
new CRLFLineReader(new InputStreamReader(_input_,
encoding));
writer =
new BufferedWriter(new OutputStreamWriter(_output_,
encoding));
getReply();
}
/**
* Closes the connection to the SMTP server and sets to null
* some internal data so that the memory may be reclaimed by the
* garbage collector. The reply text and code information from the
* last command is voided so that the memory it used may be reclaimed.
*
* @throws IOException If an error occurs while disconnecting.
*/
@Override
public void disconnect() throws IOException
{
super.disconnect();
reader = null;
writer = null;
replyString = null;
replyLines.clear();
newReplyString = false;
}
/**
* Sends an SMTP command to the server, waits for a reply and returns the
* numerical response code. After invocation, for more detailed
* information, the actual reply text can be accessed by calling
* {@link #getReplyString getReplyString } or
* {@link #getReplyStrings getReplyStrings }.
*
* @param command The text representation of the SMTP command to send.
* @param args The arguments to the SMTP command. If this parameter is
* set to null, then the command is sent with no argument.
* @return The integer value of the SMTP reply code returned by the server
* in response to the command.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int sendCommand(final String command, final String args) throws IOException
{
return sendCommand(command, args, true);
}
/**
* Sends an SMTP command to the server, waits for a reply and returns the
* numerical response code. After invocation, for more detailed
* information, the actual reply text can be accessed by calling
* {@link #getReplyString getReplyString } or
* {@link #getReplyStrings getReplyStrings }.
*
* @param command The SMTPCommand constant corresponding to the SMTP command
* to send.
* @param args The arguments to the SMTP command. If this parameter is
* set to null, then the command is sent with no argument.
* @return The integer value of the SMTP reply code returned by the server
* in response to the command.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int sendCommand(final int command, final String args) throws IOException
{
return sendCommand(SMTPCommand.getCommand(command), args);
}
/**
* Sends an SMTP command with no arguments to the server, waits for a
* reply and returns the numerical response code. After invocation, for
* more detailed information, the actual reply text can be accessed by
* calling {@link #getReplyString getReplyString } or
* {@link #getReplyStrings getReplyStrings }.
*
* @param command The text representation of the SMTP command to send.
* @return The integer value of the SMTP reply code returned by the server
* in response to the command.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int sendCommand(final String command) throws IOException
{
return sendCommand(command, null);
}
/**
* Sends an SMTP command with no arguments to the server, waits for a
* reply and returns the numerical response code. After invocation, for
* more detailed information, the actual reply text can be accessed by
* calling {@link #getReplyString getReplyString } or
* {@link #getReplyStrings getReplyStrings }.
*
* @param command The SMTPCommand constant corresponding to the SMTP command
* to send.
* @return The integer value of the SMTP reply code returned by the server
* in response to the command.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int sendCommand(final int command) throws IOException
{
return sendCommand(command, null);
}
/**
* Returns the integer value of the reply code of the last SMTP reply.
* You will usually only use this method after you connect to the
* SMTP server to check that the connection was successful since
* connect
is of type void.
*
* @return The integer value of the reply code of the last SMTP reply.
*/
public int getReplyCode()
{
return replyCode;
}
/**
* Fetches a reply from the SMTP server and returns the integer reply
* code. After calling this method, the actual reply text can be accessed
* from either calling {@link #getReplyString getReplyString } or
* {@link #getReplyStrings getReplyStrings }. Only use this
* method if you are implementing your own SMTP client or if you need to
* fetch a secondary response from the SMTP server.
*
* @return The integer value of the reply code of the fetched SMTP reply.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while receiving the
* server reply.
*/
public int getReply() throws IOException
{
final int length;
newReplyString = true;
replyLines.clear();
String line = reader.readLine();
if (line == null) {
throw new SMTPConnectionClosedException(
"Connection closed without indication.");
}
// In case we run into an anomaly we don't want fatal index exceptions
// to be thrown.
length = line.length();
if (length < 3) {
throw new MalformedServerReplyException(
"Truncated server reply: " + line);
}
try
{
final String code = line.substring(0, 3);
replyCode = Integer.parseInt(code);
}
catch (final NumberFormatException e)
{
throw new MalformedServerReplyException(
"Could not parse response code.\nServer Reply: " + line);
}
replyLines.add(line);
// Get extra lines if message continues.
if (length > 3 && line.charAt(3) == '-')
{
do
{
line = reader.readLine();
if (line == null) {
throw new SMTPConnectionClosedException(
"Connection closed without indication.");
}
replyLines.add(line);
// The length() check handles problems that could arise from readLine()
// returning too soon after encountering a naked CR or some other
// anomaly.
}
while (!(line.length() >= 4 && line.charAt(3) != '-' &&
Character.isDigit(line.charAt(0))));
// This is too strong a condition because a non-conforming server
// could screw things up like ftp.funet.fi does for FTP
// line.startsWith(code)));
}
fireReplyReceived(replyCode, getReplyString());
if (replyCode == SMTPReply.SERVICE_NOT_AVAILABLE) {
throw new SMTPConnectionClosedException(
"SMTP response 421 received. Server closed connection.");
}
return replyCode;
}
/**
* Returns the lines of text from the last SMTP server response as an array
* of strings, one entry per line. The end of line markers of each are
* stripped from each line.
*
* @return The lines of text from the last SMTP response as an array.
*/
public String[] getReplyStrings()
{
return replyLines.toArray(NetConstants.EMPTY_STRING_ARRAY);
}
/**
* Returns the entire text of the last SMTP server response exactly
* as it was received, including all end of line markers in NETASCII
* format.
*
* @return The entire text from the last SMTP response as a String.
*/
public String getReplyString()
{
final StringBuilder buffer;
if (!newReplyString) {
return replyString;
}
buffer = new StringBuilder();
for (final String line : replyLines)
{
buffer.append(line);
buffer.append(SocketClient.NETASCII_EOL);
}
newReplyString = false;
replyString = buffer.toString();
return replyString;
}
/**
* A convenience method to send the SMTP HELO command to the server,
* receive the reply, and return the reply code.
*
* @param hostname The hostname of the sender.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int helo(final String hostname) throws IOException
{
return sendCommand(SMTPCommand.HELO, hostname);
}
/**
* A convenience method to send the SMTP MAIL command to the server,
* receive the reply, and return the reply code.
*
* @param reversePath The reverese path.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int mail(final String reversePath) throws IOException
{
return sendCommand(SMTPCommand.MAIL, reversePath, false);
}
/**
* A convenience method to send the SMTP RCPT command to the server,
* receive the reply, and return the reply code.
*
* @param forwardPath The forward path.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int rcpt(final String forwardPath) throws IOException
{
return sendCommand(SMTPCommand.RCPT, forwardPath, false);
}
/**
* A convenience method to send the SMTP DATA command to the server,
* receive the reply, and return the reply code.
*
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int data() throws IOException
{
return sendCommand(SMTPCommand.DATA);
}
/**
* A convenience method to send the SMTP SEND command to the server,
* receive the reply, and return the reply code.
*
* @param reversePath The reverese path.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int send(final String reversePath) throws IOException
{
return sendCommand(SMTPCommand.SEND, reversePath);
}
/**
* A convenience method to send the SMTP SOML command to the server,
* receive the reply, and return the reply code.
*
* @param reversePath The reverese path.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int soml(final String reversePath) throws IOException
{
return sendCommand(SMTPCommand.SOML, reversePath);
}
/**
* A convenience method to send the SMTP SAML command to the server,
* receive the reply, and return the reply code.
*
* @param reversePath The reverese path.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int saml(final String reversePath) throws IOException
{
return sendCommand(SMTPCommand.SAML, reversePath);
}
/**
* A convenience method to send the SMTP RSET command to the server,
* receive the reply, and return the reply code.
*
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int rset() throws IOException
{
return sendCommand(SMTPCommand.RSET);
}
/**
* A convenience method to send the SMTP VRFY command to the server,
* receive the reply, and return the reply code.
*
* @param user The user address to verify.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int vrfy(final String user) throws IOException
{
return sendCommand(SMTPCommand.VRFY, user);
}
/**
* A convenience method to send the SMTP VRFY command to the server,
* receive the reply, and return the reply code.
*
* @param name The name to expand.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int expn(final String name) throws IOException
{
return sendCommand(SMTPCommand.EXPN, name);
}
/**
* A convenience method to send the SMTP HELP command to the server,
* receive the reply, and return the reply code.
*
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int help() throws IOException
{
return sendCommand(SMTPCommand.HELP);
}
/**
* A convenience method to send the SMTP HELP command to the server,
* receive the reply, and return the reply code.
*
* @param command The command name on which to request help.
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int help(final String command) throws IOException
{
return sendCommand(SMTPCommand.HELP, command);
}
/**
* A convenience method to send the SMTP NOOP command to the server,
* receive the reply, and return the reply code.
*
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int noop() throws IOException
{
return sendCommand(SMTPCommand.NOOP);
}
/**
* A convenience method to send the SMTP TURN command to the server,
* receive the reply, and return the reply code.
*
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int turn() throws IOException
{
return sendCommand(SMTPCommand.TURN);
}
/**
* A convenience method to send the SMTP QUIT command to the server,
* receive the reply, and return the reply code.
*
* @return The reply code received from the server.
* @throws SMTPConnectionClosedException
* If the SMTP server prematurely closes the connection as a result
* of the client being idle or some other reason causing the server
* to send SMTP reply code 421. This exception may be caught either
* as an IOException or independently as itself.
* @throws IOException If an I/O error occurs while either sending the
* command or receiving the server reply.
*/
public int quit() throws IOException
{
return sendCommand(SMTPCommand.QUIT);
}
/**
* Removes a ProtocolCommandListener.
*
* Delegates this incorrectly named method - removeProtocolCommandistener (note the missing "L")- to
* the correct method {@link SocketClient#removeProtocolCommandListener}
* @param listener The ProtocolCommandListener to remove
*/
public void removeProtocolCommandistener(final org.apache.commons.net.ProtocolCommandListener listener){
removeProtocolCommandListener(listener);
}
/**
* Provide command support to super-class
*/
@Override
protected ProtocolCommandSupport getCommandSupport() {
return _commandSupport_;
}
}