Package org.apache.commons.net.smtp

Class SMTP

java.lang.Object
org.apache.commons.net.SocketClient
org.apache.commons.net.smtp.SMTP
Direct Known Subclasses:
SMTPClient
public class SMTP extends SocketClient
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 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 SMTPReply.SERVICE_NOT_AVAILABLE response to a command. When that occurs, the SMTP class method encountering that reply will throw an 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 SMTPConnectionClosedException , you must disconnect the connection with disconnect() to properly clean up the system resources used by SMTP. Before disconnecting, you may check the last reply code and text with getReplyCode , getReplyString , and 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 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 Also:

  • Field Details

    • DEFAULT_PORT

      public static final int DEFAULT_PORT
      The default SMTP port (25).
      See Also:

    • encoding

      protected final String encoding
      The encoding to use (user-settable).
      Since:
      3.1 (changed from private to protected)

    • _commandSupport_

      protected ProtocolCommandSupport _commandSupport_
      A ProtocolCommandSupport object used to manage the registering of ProtocolCommandListeners and te firing of ProtocolCommandEvents.

  • Constructor Details

    • SMTP

      public SMTP()
      The default SMTP constructor. Sets the default port to DEFAULT_PORT and initializes internal data structures for saving SMTP reply information.

    • SMTP

      public SMTP(String encoding)
      Overloaded constructor where the user may specify a default encoding.
      Parameters:
      encoding - the encoing to use
      Since:
      2.0

  • Method Details

    • _connectAction_

      protected void _connectAction_() throws IOException
      Initiates control connections and gets initial reply.
      Overrides:
      _connectAction_ in class SocketClient
      Throws:
      IOException - (SocketException) if a problem occurs with the socket

    • disconnect

      public void disconnect() throws IOException
      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.

      Overrides:
      disconnect in class SocketClient
      Throws:
      IOException - If an error occurs while disconnecting.

    • sendCommand

      public int sendCommand(String command, String args) throws IOException
      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 getReplyString or getReplyStrings .

      Parameters:
      command - The text representation of the SMTP command to send.
      args - The arguments to the SMTP command. If this parameter is set to null, then the command is sent with no argument.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • sendCommand

      public int sendCommand(int command, String args) throws IOException
      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 getReplyString or getReplyStrings .

      Parameters:
      command - The SMTPCommand constant corresponding to the SMTP command to send.
      args - The arguments to the SMTP command. If this parameter is set to null, then the command is sent with no argument.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • sendCommand

      public int sendCommand(String command) throws IOException
      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 getReplyString or getReplyStrings .

      Parameters:
      command - The text representation of the SMTP command to send.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • sendCommand

      public int sendCommand(int command) throws IOException
      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 getReplyString or getReplyStrings .

      Parameters:
      command - The SMTPCommand constant corresponding to the SMTP command to send.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • getReplyCode

      public int getReplyCode()
      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.

      Returns:
      The integer value of the reply code of the last SMTP reply.

    • getReply

      public int getReply() throws IOException
      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 getReplyString or 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.

      Returns:
      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.
      IOException - If an I/O error occurs while receiving the server reply.

    • getReplyStrings

      public String[] getReplyStrings()
      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.

      Returns:
      The lines of text from the last SMTP response as an array.

    • getReplyString

      public String getReplyString()
      Returns the entire text of the last SMTP server response exactly as it was received, including all end of line markers in NETASCII format.

      Returns:
      The entire text from the last SMTP response as a String.

    • helo

      public int helo(String hostname) throws IOException
      A convenience method to send the SMTP HELO command to the server, receive the reply, and return the reply code.

      Parameters:
      hostname - The hostname of the sender.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • mail

      public int mail(String reversePath) throws IOException
      A convenience method to send the SMTP MAIL command to the server, receive the reply, and return the reply code.

      Parameters:
      reversePath - The reverese path.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • rcpt

      public int rcpt(String forwardPath) throws IOException
      A convenience method to send the SMTP RCPT command to the server, receive the reply, and return the reply code.

      Parameters:
      forwardPath - The forward path.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • data

      public int data() throws IOException
      A convenience method to send the SMTP DATA command to the server, receive the reply, and return the reply code.

      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • send

      public int send(String reversePath) throws IOException
      A convenience method to send the SMTP SEND command to the server, receive the reply, and return the reply code.

      Parameters:
      reversePath - The reverese path.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • soml

      public int soml(String reversePath) throws IOException
      A convenience method to send the SMTP SOML command to the server, receive the reply, and return the reply code.

      Parameters:
      reversePath - The reverese path.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • saml

      public int saml(String reversePath) throws IOException
      A convenience method to send the SMTP SAML command to the server, receive the reply, and return the reply code.

      Parameters:
      reversePath - The reverese path.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • rset

      public int rset() throws IOException
      A convenience method to send the SMTP RSET command to the server, receive the reply, and return the reply code.

      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • vrfy

      public int vrfy(String user) throws IOException
      A convenience method to send the SMTP VRFY command to the server, receive the reply, and return the reply code.

      Parameters:
      user - The user address to verify.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • expn

      public int expn(String name) throws IOException
      A convenience method to send the SMTP VRFY command to the server, receive the reply, and return the reply code.

      Parameters:
      name - The name to expand.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • help

      public int help() throws IOException
      A convenience method to send the SMTP HELP command to the server, receive the reply, and return the reply code.

      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • help

      public int help(String command) throws IOException
      A convenience method to send the SMTP HELP command to the server, receive the reply, and return the reply code.

      Parameters:
      command - The command name on which to request help.
      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • noop

      public int noop() throws IOException
      A convenience method to send the SMTP NOOP command to the server, receive the reply, and return the reply code.

      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • turn

      public int turn() throws IOException
      A convenience method to send the SMTP TURN command to the server, receive the reply, and return the reply code.

      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • quit

      public int quit() throws IOException
      A convenience method to send the SMTP QUIT command to the server, receive the reply, and return the reply code.

      Returns:
      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.
      IOException - If an I/O error occurs while either sending the command or receiving the server reply.

    • removeProtocolCommandistener

      public void removeProtocolCommandistener(ProtocolCommandListener listener)
      Removes a ProtocolCommandListener. Delegates this incorrectly named method - removeProtocolCommandistener (note the missing "L")- to the correct method SocketClient.removeProtocolCommandListener(org.apache.commons.net.ProtocolCommandListener)
      Parameters:
      listener - The ProtocolCommandListener to remove

    • getCommandSupport

      protected ProtocolCommandSupport getCommandSupport()
      Provide command support to super-class
      Overrides:
      getCommandSupport in class SocketClient
      Returns:
      the CommandSupport instance, may be null