Package jakarta.servlet

Interface AsyncListener

All Superinterfaces:

EventListener

public interface AsyncListener
extends EventListener

Listener that will be notified in the event that an asynchronous operation initiated on a ServletRequest to which the listener had been added has completed, timed out, or resulted in an error.

Since:

Servlet 3.0

Method Summary

Modifier and Type	Method	Description
void	onComplete(AsyncEvent event)	Notifies this AsyncListener that an asynchronous operation has been completed.
void	onError(AsyncEvent event)	Notifies this AsyncListener that an asynchronous operation has failed to complete.
void	onStartAsync(AsyncEvent event)	Notifies this AsyncListener that a new asynchronous cycle is being initiated via a call to one of the ServletRequest.startAsync() methods.
void	onTimeout(AsyncEvent event)	Notifies this AsyncListener that an asynchronous operation has timed out.

Method Details

onComplete

void onComplete(AsyncEvent event) throws IOException

Notifies this AsyncListener that an asynchronous operation has been completed.

The AsyncContext corresponding to the asynchronous operation that has been completed may be obtained by calling getAsyncContext on the given event.

In addition, if this AsyncListener had been registered via a call to AsyncContext.addListener(AsyncListener, ServletRequest, ServletResponse), the supplied ServletRequest and ServletResponse objects may be retrieved by calling getSuppliedRequest and getSuppliedResponse, respectively, on the given event.

Parameters:

event - the AsyncEvent indicating that an asynchronous operation has been completed

Throws:

IOException - if an I/O related error has occurred during the processing of the given AsyncEvent

onTimeout

void onTimeout(AsyncEvent event) throws IOException

Notifies this AsyncListener that an asynchronous operation has timed out.

The AsyncContext corresponding to the asynchronous operation that has timed out may be obtained by calling getAsyncContext on the given event.

In addition, if this AsyncListener had been registered via a call to AsyncContext.addListener(AsyncListener, ServletRequest, ServletResponse), the supplied ServletRequest and ServletResponse objects may be retrieved by calling getSuppliedRequest and getSuppliedResponse, respectively, on the given event.

Parameters:

event - the AsyncEvent indicating that an asynchronous operation has timed out

Throws:

IOException - if an I/O related error has occurred during the processing of the given AsyncEvent

onError

void onError(AsyncEvent event) throws IOException

Notifies this AsyncListener that an asynchronous operation has failed to complete.

The AsyncContext corresponding to the asynchronous operation that failed to complete may be obtained by calling getAsyncContext on the given event.

In addition, if this AsyncListener had been registered via a call to AsyncContext.addListener(AsyncListener, ServletRequest, ServletResponse), the supplied ServletRequest and ServletResponse objects may be retrieved by calling getSuppliedRequest and getSuppliedResponse, respectively, on the given event.

Parameters:

event - the AsyncEvent indicating that an asynchronous operation has failed to complete

Throws:

IOException - if an I/O related error has occurred during the processing of the given AsyncEvent

onStartAsync

void onStartAsync(AsyncEvent event) throws IOException

Notifies this AsyncListener that a new asynchronous cycle is being initiated via a call to one of the ServletRequest.startAsync() methods.

The AsyncContext corresponding to the asynchronous operation that is being reinitialized may be obtained by calling getAsyncContext on the given event.

In addition, if this AsyncListener had been registered via a call to AsyncContext.addListener(AsyncListener, ServletRequest, ServletResponse), the supplied ServletRequest and ServletResponse objects may be retrieved by calling getSuppliedRequest and getSuppliedResponse, respectively, on the given event.

This AsyncListener will not receive any events related to the new asynchronous cycle unless it registers itself (via a call to AsyncContext.addListener(jakarta.servlet.AsyncListener)) with the AsyncContext that is delivered as part of the given AsyncEvent.

Parameters:

event - the AsyncEvent indicating that a new asynchronous cycle is being initiated

Throws:

IOException - if an I/O related error has occurred during the processing of the given AsyncEvent