org.apache.samza.context

Interface ApplicationTaskContext

public interface ApplicationTaskContext

An ApplicationTaskContext instance can be used for holding per-task runtime state and objects and managing their lifecycle in an SamzaApplication

Use ApplicationDescriptor.withApplicationTaskContextFactory(org.apache.samza.context.ApplicationTaskContextFactory<?>) to provide the ApplicationTaskContextFactory. Use Context.getApplicationTaskContext() to get the created ApplicationTaskContext instance for the current task.

A unique instance of ApplicationTaskContext is created for each task in a container. Use the ApplicationTaskContextFactory to create any runtime state and objects, and the start() and stop() methods to manage their lifecycle.

Use ApplicationContainerContext to hold runtime state and objects shared across all tasks within a container. Use TaskContext to access framework-provided context for a task.

Unlike its ApplicationTaskContextFactory, an implementation does not need to be Serializable.

Method Summary

Modifier and Type	Method and Description
void	start() Starts this ApplicationTaskContext after its task is initialized but before any messages are processed.
void	stop() Stops this ApplicationTaskContext after processing ends but before its task is closed.

Method Detail

start

void start()

Starts this ApplicationTaskContext after its task is initialized but before any messages are processed.

If this throws an exception, the container will fail to start.

stop

void stop()

Stops this ApplicationTaskContext after processing ends but before its task is closed.

If this throws an exception, the container will fail to fully shut down.