net.markenwerk.commons.interfaces

Interface Callback<Result>

Type Parameters:

Result - The type of the result of the process.

public interface Callback<Result>

For an arbitrary process, that will eventually yield a result, a Callback is used, to convey that result from the executor of the process (hereafter: executor) back to the initiator of the process (hereafter: initiator).

A Callback is most likely, but not necessarily, used in a multithreaded scenario.

Depending on the concrete scenario, the initiator may reuse the same instance of Callback for multiple processes and even for the same executor, although the letter is unusual.

The executor must eventually call onResult(Object), at least once.

One common exception to this rule is, when the executor can ensure, that the result wont't be needed by the initiator, because the initiator itself is not needed anymore. This is usually implemented by placing the Callback in a WeakReference. This should be noted in the contract of the method, that is used to convey the Callback to the executor, because using anonymous instances of Callback will fail in this case.

The executor may call onResult(Object), more than once, depending o the concrete scenario, to convey partial or updated results. This should be noted in the contract of the method, that is used to convey the Callback to the executor.

The executor must not call onResult(Object) more than once for the same result.

Since:

1.0.0

Author:

Torsten Krause (tk at markenwerk dot net)

Method Summary

Modifier and Type	Method and Description
void	onResult(Result result) Called by the executor when a result is available.

Method Detail

onResult

void onResult(Result result)

Called by the executor when a result is available.

Parameters:

result - The result.