com.bah.geterdun

Class GeterDun<EVENT>

java.lang.Object

com.bah.geterdun.GeterDun<EVENT>

Type Parameters:

EVENT - The type of the event to process.

All Implemented Interfaces:

Closeable, AutoCloseable

public class GeterDun<EVENT>
extends Object
implements Closeable

Processes events and retries them periodically if they fail to process.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GeterDun.CantGeterDunException

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
static <EVENT> GeterDun<EVENT>	geterDun(Class<EVENT> eventClass, String location, EventProcessor<EVENT> processor) Creates a new GeterDun that swallows log corruption exceptions and processing exceptions, and rotates logs every hour.
static <EVENT> GeterDun<EVENT>	geterDun(Class<EVENT> eventClass, String location, EventProcessor<EVENT> processor, CorruptionHandler corruptionHandler, long frequency, FailureHandler<EVENT> failureHandler)
void	geterDun(EVENT event) Durably records an event and will periodically retry it if the first attempt to write the event doesn't succeed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

geterDun

public static <EVENT> GeterDun<EVENT> geterDun(Class<EVENT> eventClass,
                               String location,
                               EventProcessor<EVENT> processor,
                               CorruptionHandler corruptionHandler,
                               long frequency,
                               FailureHandler<EVENT> failureHandler)
                                throws GeterDun.CantGeterDunException

Parameters:

eventClass - The class of the event to process. Presently, must inherit from Writable.

location - A URI referencing a location for storing logs.

processor - An implementation of a processing algorithm that will be applied to each event.

corruptionHandler - Gets notified of log corruption exceptions. These events should be very rare, but are conditioned on the reliability of the underlying file system.

frequency - How frequently to rotate logs. Lower this parameter if you encounter issues with OutOfMemoryErrors, or if your log frequency exceeds more than about 4 billion entries per hour.

failureHandler - Gets notified of unrecoverable processing failures.

Returns:

A GeterDun that you can post events to.

Throws:

GeterDun.CantGeterDunException - If a prerequisite is not met, such as access to the underlying file system or one of the conditions above not being met.

geterDun

public static <EVENT> GeterDun<EVENT> geterDun(Class<EVENT> eventClass,
                               String location,
                               EventProcessor<EVENT> processor)
                                throws GeterDun.CantGeterDunException

Creates a new GeterDun that swallows log corruption exceptions and processing exceptions, and rotates logs every hour.

Parameters:

eventClass - The class of the event to process. Presently, must inherit from Writable.

location - A URI referencing a location for storing logs.

processor - An implementation of a processing algorithm that will be applied to each event.

Returns:

A GeterDun that you can post events to.

Throws:

GeterDun.CantGeterDunException - If a prerequisite is not met, such as access to the underlying file system or one of the conditions above not being met.

geterDun

public void geterDun(EVENT event)
              throws FinalFailureException,
                     GeterDun.CantGeterDunException

Durably records an event and will periodically retry it if the first attempt to write the event doesn't succeed.

Parameters:

event - The event to write.

Throws:

FinalFailureException - If the event cannot be processed and will never be processed.

GeterDun.CantGeterDunException - If the event was recorded to the log and either was processed, or may be processed in the future, but an error has prevented communication with the log.

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException