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package org.apache.mailet;
/**
* Draft of a Mailet inteface. The <code>service</code> perform all needed work
* on the Mail object. Whatever remains at the end of the service is considered
* to need futher processing and will go to the next Mailet if there is one
* configured or will go to the error processor if not.
* Setting a Mail state (setState(String)) to Mail.GHOST or cleaning its recipient
* list has the same meaning that s no more processing is needed.
* Instead of creating new messages, the mailet can put a message with new recipients
* at the top of the mail queue, or insert them immediately after it's execution
* through the API are provided by the MailetContext interface.
* <p>
* This interface defines methods to initialize a mailet, to service messages, and to
* remove a mailet from the server. These are known as life-cycle methods and are called
* in the following sequence:
* <ol>
* <li>The mailet is constructed, then initialized with the init method. </li>
* <li>Any messages for the service method are handled.</li>
* <li>The mailet is taken out of service, then destroyed with the destroy method,
* then garbage collected and finalized.</li>
* </ol>
* In addition to the life-cycle methods, this interface provides the getMailetConfig
* method, which the mailet can use to get any startup information, and the
* getMailetInfo method, which allows the mailet to return basic information about itself,
* such as author, version, and copyright.
*
* @version 1.0.0, 24/04/1999
*/
public interface Mailet {
/**
* Called by the mailet container to indicate to a mailet that the
* mailet is being taken out of service. This method is only called once
* all threads within the mailet's service method have exited or after a
* timeout period has passed. After the mailet container calls this method,
* it will not call the service method again on this mailet.
* <p>
* This method gives the mailet an opportunity to clean up any resources that
* are being held (for example, memory, file handles, threads) and make sure
* that any persistent state is synchronized with the mailet's current state in memory.
*/
void destroy();
/**
* Returns information about the mailet, such as author, version, and
* copyright.
* <p>
* The string that this method returns should be plain text and not markup
* of any kind (such as HTML, XML, etc.).
*
* @return a String containing servlet information
*/
String getMailetInfo();
/**
* Returns a MailetConfig object, which contains initialization and
* startup parameters for this mailet.
* <p>
* Implementations of this interface are responsible for storing the MailetConfig
* object so that this method can return it. The GenericMailet class, which implements
* this interface, already does this.
*
* @return the MailetConfig object that initializes this mailet
*/
MailetConfig getMailetConfig();
/**
* Called by the mailet container to indicate to a mailet that the
* mailet is being placed into service.
* <p>
* The mailet container calls the init method exactly once after
* instantiating the mailet. The init method must complete successfully
* before the mailet can receive any requests.
*
* @param config - a MailetConfig object containing the mailet's configuration
* and initialization parameters
* @throws javax.mail.MessagingException - if an exception has occurred that interferes with
* the mailet's normal operation
*/
void init(MailetConfig config) throws javax.mail.MessagingException;
/**
* Called by the mailet container to allow the mailet to process to
* a message.
* <p>
* This method is only called after the mailet's init() method has completed
* successfully.
* <p>
* Mailets typically run inside multithreaded mailet containers that can handle
* multiple requests concurrently. Developers must be aware to synchronize access
* to any shared resources such as files, network connections, as well as the
* mailet's class and instance variables. More information on multithreaded
* programming in Java is available in <a href="http://java.sun.com/Series/Tutorial/java/threads/multithreaded.html">the
* Java tutorial on multi-threaded programming</a>.
*
* @param mail - the Mail object that contains the message and routing information
* @throws javax.mail.MessagingException - if a message or address parsing exception occurs or
* an exception that interferes with the mailet's normal operation
*/
void service(Mail mail) throws javax.mail.MessagingException;
}
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