Java tutorial
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However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ 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 */ public interface AsyncListener extends EventListener { /** * 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. * * <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. * * <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 {@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; }