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org.apache.commons.net.smtp
Class SMTPClient  view SMTPClient download SMTPClient.java

java.lang.Object
  extended byorg.apache.commons.net.SocketClient
      extended byorg.apache.commons.net.smtp.SMTP
          extended byorg.apache.commons.net.smtp.SMTPClient

public class SMTPClient
extends SMTP

SMTPClient encapsulates all the functionality necessary to send files through an SMTP server. This class takes care of all low level details of interacting with an SMTP server and provides a convenient higher level interface. As with all classes derived from org.apache.commons.net.SocketClient, you must first connect to the server with connect 55 before doing anything, and finally disconnect 55 after you're completely finished interacting with the server. Then you need to check the SMTP reply code to see if the connection was successful. For example:

    try {
      int reply;
      client.connect("mail.foobar.com");
      System.out.print(client.getReplyString());

      // After connection attempt, you should check the reply code to verify
      // success.
      reply = client.getReplyCode();

      if(!SMTPReply.isPositiveCompletion(reply)) {
        client.disconnect();
        System.err.println("SMTP server refused connection.");
        System.exit(1);
      }

      // Do useful stuff here.
      ...
    } catch(IOException e) {
      if(client.isConnected()) {
        try {
          client.disconnect();
        } catch(IOException f) {
          // do nothing
        }
      }
      System.err.println("Could not connect to server.");
      e.printStackTrace();
      System.exit(1);
    }
 

Immediately after connecting is the only real time you need to check the reply code (because connect is of type void). The convention for all the SMTP command methods in SMTPClient is such that they either return a boolean value or some other value. The boolean methods return true on a successful completion reply from the SMTP server and false on a reply resulting in an error condition or failure. The methods returning a value other than boolean return a value containing the higher level data produced by the SMTP command, or null if a reply resulted in an error condition or failure. If you want to access the exact SMTP reply code causing a success or failure, you must call getReplyCode 55 after a success or failure.

You should keep in mind that the SMTP server may choose to prematurely close a connection for various reasons. The SMTPClient class will detect a premature SMTP server connection closing when it receives a SMTPReply.SERVICE_NOT_AVAILABLE 55 response to a command. When that occurs, the 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() 55 to properly clean up the system resources used by SMTPClient. Before disconnecting, you may check the last reply code and text with getReplyCode 55 , getReplyString 55 , and getReplyStrings 55 .

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 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.


Field Summary
 
Fields inherited from class org.apache.commons.net.smtp.SMTP
_commandSupport_, _newReplyString, _reader, _replyCode, _replyLines, _replyString, _writer, DEFAULT_PORT
 
Fields inherited from class org.apache.commons.net.SocketClient
_defaultPort_, _input_, _isConnected_, _output_, _socket_, _socketFactory_, _timeout_, NETASCII_EOL
 
Constructor Summary
SMTPClient()
           
 
Method Summary
 boolean addRecipient(RelayPath path)
          Add a recipient for a message using the SMTP RCPT command, specifying a forward relay path.
 boolean addRecipient(java.lang.String address)
          Add a recipient for a message using the SMTP RCPT command, the recipient's email address.
 boolean completePendingCommand()
          At least one SMTPClient method (sendMessageData 55 ) does not complete the entire sequence of SMTP commands to complete a transaction.
 java.lang.String listHelp()
          Fetches the system help information from the server and returns the full string.
 java.lang.String listHelp(java.lang.String command)
          Fetches the help information for a given command from the server and returns the full string.
 boolean login()
          Login to the SMTP server by sending the HELO command with the client hostname as an argument.
 boolean login(java.lang.String hostname)
          Login to the SMTP server by sending the HELO command with the given hostname as an argument.
 boolean logout()
          Logout of the SMTP server by sending the QUIT command.
 boolean reset()
          Aborts the current mail transaction, resetting all server stored sender, recipient, and mail data, cleaing all buffers and tables.
 java.io.Writer sendMessageData()
          Send the SMTP DATA command in preparation to send an email message.
 boolean sendNoOp()
          Sends a NOOP command to the SMTP server.
 boolean sendShortMessageData(java.lang.String message)
          A convenience method for sending short messages.
 boolean sendSimpleMessage(java.lang.String sender, java.lang.String[] recipients, java.lang.String message)
          A convenience method for a sending short email without having to explicitly set the sender and recipient(s).
 boolean sendSimpleMessage(java.lang.String sender, java.lang.String recipient, java.lang.String message)
          A convenience method for a sending short email without having to explicitly set the sender and recipient(s).
 boolean setSender(RelayPath path)
          Set the sender of a message using the SMTP MAIL command, specifying a reverse relay path.
 boolean setSender(java.lang.String address)
          Set the sender of a message using the SMTP MAIL command, specifying the sender's email address.
 boolean verify(java.lang.String username)
          Verify that a username or email address is valid, i.e., that mail can be delivered to that mailbox on the server.
 
Methods inherited from class org.apache.commons.net.smtp.SMTP
_connectAction_, addProtocolCommandListener, data, disconnect, expn, getReply, getReplyCode, getReplyString, getReplyStrings, helo, help, help, mail, noop, quit, rcpt, removeProtocolCommandistener, rset, saml, send, sendCommand, sendCommand, sendCommand, sendCommand, soml, turn, vrfy
 
Methods inherited from class org.apache.commons.net.SocketClient
connect, connect, connect, connect, connect, connect, getDefaultPort, getDefaultTimeout, getLocalAddress, getLocalPort, getRemoteAddress, getRemotePort, getSoLinger, getSoTimeout, getTcpNoDelay, isConnected, setDefaultPort, setDefaultTimeout, setSocketFactory, setSoLinger, setSoTimeout, setTcpNoDelay, verifyRemote
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SMTPClient

public SMTPClient()
Method Detail

completePendingCommand

public boolean completePendingCommand()
                               throws java.io.IOException
At least one SMTPClient method (sendMessageData 55 ) does not complete the entire sequence of SMTP commands to complete a transaction. These types of commands require some action by the programmer after the reception of a positive intermediate command. After the programmer's code completes its actions, it must call this method to receive the completion reply from the server and verify the success of the entire transaction.

For example,

 writer = client.sendMessage();
 if(writer == null) // failure
   return false;
 header =
  new SimpleSMTPHeader("foobar@foo.com", "foo@foobar.com", "Re: Foo");
 writer.write(header.toString());
 writer.write("This is just a test");
 writer.close();
 if(!client.completePendingCommand()) // failure
   return false;
 


login

public boolean login(java.lang.String hostname)
              throws java.io.IOException
Login to the SMTP server by sending the HELO command with the given hostname as an argument. Before performing any mail commands, you must first login.


login

public boolean login()
              throws java.io.IOException
Login to the SMTP server by sending the HELO command with the client hostname as an argument. Before performing any mail commands, you must first login.


setSender

public boolean setSender(RelayPath path)
                  throws java.io.IOException
Set the sender of a message using the SMTP MAIL command, specifying a reverse relay path. The sender must be set first before any recipients may be specified, otherwise the mail server will reject your commands.


setSender

public boolean setSender(java.lang.String address)
                  throws java.io.IOException
Set the sender of a message using the SMTP MAIL command, specifying the sender's email address. The sender must be set first before any recipients may be specified, otherwise the mail server will reject your commands.


addRecipient

public boolean addRecipient(RelayPath path)
                     throws java.io.IOException
Add a recipient for a message using the SMTP RCPT command, specifying a forward relay path. The sender must be set first before any recipients may be specified, otherwise the mail server will reject your commands.


addRecipient

public boolean addRecipient(java.lang.String address)
                     throws java.io.IOException
Add a recipient for a message using the SMTP RCPT command, the recipient's email address. The sender must be set first before any recipients may be specified, otherwise the mail server will reject your commands.


sendMessageData

public java.io.Writer sendMessageData()
                               throws java.io.IOException
Send the SMTP DATA command in preparation to send an email message. This method returns a DotTerminatedMessageWriter instance to which the message can be written. Null is returned if the DATA command fails.

You must not issue any commands to the SMTP server (i.e., call any (other methods) until you finish writing to the returned Writer instance and close it. The SMTP protocol uses the same stream for issuing commands as it does for returning results. Therefore the returned Writer actually writes directly to the SMTP connection. After you close the writer, you can execute new commands. If you do not follow these requirements your program will not work properly.

You can use the provided SimpleSMTPHeader class to construct a bare minimum header. To construct more complicated headers you should refer to RFC 822. When the Java Mail API is finalized, you will be able to use it to compose fully compliant Internet text messages. The DotTerminatedMessageWriter takes care of doubling line-leading dots and ending the message with a single dot upon closing, so all you have to worry about is writing the header and the message.

Upon closing the returned Writer, you need to call completePendingCommand() 55 to finalize the transaction and verify its success or failure from the server reply.


sendShortMessageData

public boolean sendShortMessageData(java.lang.String message)
                             throws java.io.IOException
A convenience method for sending short messages. This method fetches the Writer returned by sendMessageData() 55 and writes the specified String to it. After writing the message, this method calls completePendingCommand() 55 to finalize the transaction and returns its success or failure.


sendSimpleMessage

public boolean sendSimpleMessage(java.lang.String sender,
                                 java.lang.String recipient,
                                 java.lang.String message)
                          throws java.io.IOException
A convenience method for a sending short email without having to explicitly set the sender and recipient(s). This method sets the sender and recipient using setSender 55 and addRecipient 55 , and then sends the message using sendShortMessageData 55 .


sendSimpleMessage

public boolean sendSimpleMessage(java.lang.String sender,
                                 java.lang.String[] recipients,
                                 java.lang.String message)
                          throws java.io.IOException
A convenience method for a sending short email without having to explicitly set the sender and recipient(s). This method sets the sender and recipients using setSender 55 and addRecipient 55 , and then sends the message using sendShortMessageData 55 .


logout

public boolean logout()
               throws java.io.IOException
Logout of the SMTP server by sending the QUIT command.


reset

public boolean reset()
              throws java.io.IOException
Aborts the current mail transaction, resetting all server stored sender, recipient, and mail data, cleaing all buffers and tables.


verify

public boolean verify(java.lang.String username)
               throws java.io.IOException
Verify that a username or email address is valid, i.e., that mail can be delivered to that mailbox on the server.


listHelp

public java.lang.String listHelp()
                          throws java.io.IOException
Fetches the system help information from the server and returns the full string.


listHelp

public java.lang.String listHelp(java.lang.String command)
                          throws java.io.IOException
Fetches the help information for a given command from the server and returns the full string.


sendNoOp

public boolean sendNoOp()
                 throws java.io.IOException
Sends a NOOP command to the SMTP server. This is useful for preventing server timeouts.