SMTP.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.
*/
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.
* <p>
* 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} .
* <code>SMTPConnectionClosedException</code> is a subclass of <code> IOException </code> 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 <code> IOException </code> 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}.
* </p>
* <p>
* 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.
* </p>
*
* @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<String> replyLines;
private boolean newReplyString;
private String replyString;
/**
* The default SMTP constructor. Sets the default port to <code>DEFAULT_PORT</code> 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 encoding 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;
}
/** 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();
}
/**
* 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);
}
/**
* 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;
}
/**
* 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);
}
/**
* Provide command support to super-class
*/
@Override
protected ProtocolCommandSupport getCommandSupport() {
return _commandSupport_;
}
/**
* 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 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 <code> connect </code> is of type void.
*
* @return The integer value of the reply code of the last SMTP reply.
*/
public int getReplyCode() {
return replyCode;
}
/**
* 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;
}
/**
* 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);
}
/**
* 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 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 MAIL command to the server, receive the reply, and return the reply code.
*
* @param reversePath The reverse 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 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 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);
}
/**
* 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);
}
/**
* 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);
}
/**
* 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 SAML command to the server, receive the reply, and return the reply code.
*
* @param reversePath The reverse 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 SEND command to the server, receive the reply, and return the reply code.
*
* @param reversePath The reverse 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);
}
/**
* 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);
}
/**
* 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);
}
/**
*
* @param command the command to send (as an int defined in {@link SMTPCommand})
* @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);
}
/**
* 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 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);
}
/**
* 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();
}
/**
* A convenience method to send the SMTP SOML command to the server, receive the reply, and return the reply code.
*
* @param reversePath The reverse 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 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 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);
}
}