public static enum CometEvent.EventType
extends java.lang.Enum<CometEvent.EventType>

Enumeration describing the major events that the container can invoke the CometProcessors event() method with.
BEGIN - will be called at the beginning of the processing of the connection. It can be used to initialize any relevant fields using the request and response objects. Between the end of the processing of this event, and the beginning of the processing of the end or error events, it is possible to use the response object to write data on the open connection. Note that the response object and dependent OutputStream and Writer are still not synchronized, so when they are accessed by multiple threads, synchronization is mandatory. After processing the initial event, the request is considered to be committed.
READ - This indicates that input data is available, and that one read can be made without blocking. The available and ready methods of the InputStream or Reader may be used to determine if there is a risk of blocking: the servlet should read while data is reported available. When encountering a read error, the servlet should report it by propagating the exception properly. Throwing an exception will cause the error event to be invoked, and the connection will be closed. Alternately, it is also possible to catch any exception, perform clean up on any data structure the servlet may be using, and using the close method of the event. It is not allowed to attempt reading data from the request object outside of the execution of this method.
END - End may be called to end the processing of the request. Fields that have been initialized in the begin method should be reset. After this event has been processed, the request and response objects, as well as all their dependent objects will be recycled and used to process other requests. End will also be called when data is available and the end of file is reached on the request input (this usually indicates the client has pipelined a request).
ERROR - Error will be called by the container in the case where an IO exception or a similar unrecoverable error occurs on the connection. Fields that have been initialized in the begin method should be reset. After this event has been processed, the request and response objects, as well as all their dependent objects will be recycled and used to process other requests.