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package javax.servlet;

import java.io.IOException;
import java.util.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
/**
 * 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
 */
public interface AsyncListener extends EventListener {
    
    
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.

Params:
  • 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
/**
     * Notifies this AsyncListener that an asynchronous operation
     * has been completed.
     * 
     * <p>The {@link AsyncContext} corresponding to the asynchronous
     * operation that has been completed may be obtained by calling
     * {@link AsyncEvent#getAsyncContext getAsyncContext} on the given
     * <tt>event</tt>.
     *
     * <p>In addition, if this AsyncListener had been registered via a call
     * to {@link AsyncContext#addListener(AsyncListener,
     * ServletRequest, ServletResponse)}, the supplied ServletRequest and
     * ServletResponse objects may be retrieved by calling
     * {@link AsyncEvent#getSuppliedRequest getSuppliedRequest} and
     * {@link AsyncEvent#getSuppliedResponse getSuppliedResponse},
     * respectively, on the given <tt>event</tt>.
     *
     * @param 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
     */
    public void onComplete(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.

Params:
  • 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
/**
     * Notifies this AsyncListener that an asynchronous operation
     * has timed out.
     * 
     * <p>The {@link AsyncContext} corresponding to the asynchronous
     * operation that has timed out may be obtained by calling
     * {@link AsyncEvent#getAsyncContext getAsyncContext} on the given
     * <tt>event</tt>.
     *
     * <p>In addition, if this AsyncListener had been registered via a call
     * to {@link AsyncContext#addListener(AsyncListener,
     * ServletRequest, ServletResponse)}, the supplied ServletRequest and
     * ServletResponse objects may be retrieved by calling
     * {@link AsyncEvent#getSuppliedRequest getSuppliedRequest} and
     * {@link AsyncEvent#getSuppliedResponse getSuppliedResponse},
     * respectively, on the given <tt>event</tt>.
     *
     * @param 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
     */
    public void onTimeout(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.

Params:
  • 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
/**
     * Notifies this AsyncListener that an asynchronous operation 
     * has failed to complete.
     * 
     * <p>The {@link AsyncContext} corresponding to the asynchronous
     * operation that failed to complete may be obtained by calling
     * {@link AsyncEvent#getAsyncContext getAsyncContext} on the given
     * <tt>event</tt>.
     * 
     * <p>In addition, if this AsyncListener had been registered via a call
     * to {@link AsyncContext#addListener(AsyncListener,
     * ServletRequest, ServletResponse)}, the supplied ServletRequest and
     * ServletResponse objects may be retrieved by calling
     * {@link AsyncEvent#getSuppliedRequest getSuppliedRequest} and
     * {@link AsyncEvent#getSuppliedResponse getSuppliedResponse},
     * respectively, on the given <tt>event</tt>.
     *
     * @param 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
     */
    public void onError(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) with the AsyncContext that is delivered as part of the given AsyncEvent. 
Params:
  • 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
/**
     * Notifies this AsyncListener that a new asynchronous cycle is being
     * initiated via a call to one of the {@link ServletRequest#startAsync}
     * methods.
     *
     * <p>The {@link AsyncContext} corresponding to the asynchronous
     * operation that is being reinitialized may be obtained by calling
     * {@link AsyncEvent#getAsyncContext getAsyncContext} on the given
     * <tt>event</tt>.
     * 
     * <p>In addition, if this AsyncListener had been registered via a call
     * to {@link AsyncContext#addListener(AsyncListener,
     * ServletRequest, ServletResponse)}, the supplied ServletRequest and
     * ServletResponse objects may be retrieved by calling
     * {@link AsyncEvent#getSuppliedRequest getSuppliedRequest} and
     * {@link AsyncEvent#getSuppliedResponse getSuppliedResponse},
     * respectively, on the given <tt>event</tt>.
     *
     * <p>This AsyncListener will not receive any events related to the
     * new asynchronous cycle unless it registers itself (via a call
     * to {@link AsyncContext#addListener}) with the AsyncContext that
     * is delivered as part of the given AsyncEvent.
     *
     * @param 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
     */
    public void onStartAsync(AsyncEvent event) throws IOException;     

}