org.apache.catalina.connector
Class Request.AsyncContextImpl

java.lang.Object
  org.apache.catalina.connector.Request.AsyncContextImpl

All Implemented Interfaces:

javax.servlet.AsyncContext

Enclosing class:

Request

public class Request.AsyncContextImpl
extends java.lang.Object
implements javax.servlet.AsyncContext

Field Summary

protected boolean	original
protected java.lang.String	path
protected boolean	ready
protected java.lang.Runnable	runnable
protected javax.servlet.ServletContext	servletContext
protected javax.servlet.ServletRequest	servletRequest
protected javax.servlet.ServletResponse	servletResponse
protected boolean	useAttributes

Fields inherited from interface javax.servlet.AsyncContext

ASYNC_CONTEXT_PATH, ASYNC_PATH_INFO, ASYNC_QUERY_STRING, ASYNC_REQUEST_URI, ASYNC_SERVLET_PATH

Constructor Summary

Request.AsyncContextImpl()

Method Summary

void	addListener(javax.servlet.AsyncListener listener) Registers the given AsyncListener with the most recent asynchronous cycle that was started by a call to one of the ServletRequest.startAsync() methods.
void	addListener(javax.servlet.AsyncListener listener, javax.servlet.ServletRequest servletRequest, javax.servlet.ServletResponse servletResponse) Registers the given AsyncListener with the most recent asynchronous cycle that was started by a call to one of the ServletRequest.startAsync() methods.
void	complete() Completes the asynchronous operation that was started on the request that was used to initialze this AsyncContext, closing the response that was used to initialize this AsyncContext.
<T extends javax.servlet.AsyncListener> T	createListener(java.lang.Class<T> clazz) Instantiates the given AsyncListener class.
void	dispatch() Dispatches the request and response objects of this AsyncContext to the servlet container.
void	dispatch(javax.servlet.ServletContext servletContext, java.lang.String path) Dispatches the request and response objects of this AsyncContext to the given path scoped to the given context.
void	dispatch(java.lang.String path) Dispatches the request and response objects of this AsyncContext to the given path.
void	done()
java.util.Map<javax.servlet.AsyncListener,Request.AsyncListenerRegistration>	getAsyncListeners()
java.lang.String	getPath()
javax.servlet.ServletRequest	getRequest() Gets the request that was used to initialize this AsyncContext by calling ServletRequest.startAsync() or ServletRequest.startAsync(ServletRequest, ServletResponse).
javax.servlet.ServletResponse	getResponse() Gets the response that was used to initialize this AsyncContext by calling ServletRequest.startAsync() or ServletRequest.startAsync(ServletRequest, ServletResponse).
java.lang.Runnable	getRunnable()
javax.servlet.ServletContext	getServletContext()
long	getTimeout() Gets the timeout (in milliseconds) for this AsyncContext.
boolean	getUseAttributes()
boolean	hasOriginalRequestAndResponse() Checks if this AsyncContext was initialized with the original or application-wrapped request and response objects.
boolean	isReady()
void	reset()
void	setRequestAndResponse(javax.servlet.ServletRequest servletRequest, javax.servlet.ServletResponse servletResponse)
void	setTimeout(long timeout) Sets the timeout (in milliseconds) for this AsyncContext.
void	start(java.lang.Runnable runnable) Causes the container to dispatch a thread, possibly from a managed thread pool, to run the specified Runnable.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

servletRequest

protected javax.servlet.ServletRequest servletRequest

servletResponse

protected javax.servlet.ServletResponse servletResponse

servletContext

protected javax.servlet.ServletContext servletContext

path

protected java.lang.String path

runnable

protected java.lang.Runnable runnable

useAttributes

protected boolean useAttributes

original

protected boolean original

ready

protected boolean ready

Constructor Detail

Request.AsyncContextImpl

public Request.AsyncContextImpl()

Method Detail

complete

public void complete()

Description copied from interface: javax.servlet.AsyncContext

Completes the asynchronous operation that was started on the request that was used to initialze this AsyncContext, closing the response that was used to initialize this AsyncContext.

Any listeners of type AsyncListener that were registered with the ServletRequest for which this AsyncContext was created will be invoked at their onComplete method.

It is legal to call this method any time after a call to ServletRequest.startAsync() or ServletRequest.startAsync(ServletRequest, ServletResponse), and before a call to one of the dispatch methods of this class. If this method is called before the container-initiated dispatch that called startAsync has returned to the container, then the call will not take effect (and any invocations of AsyncListener.onComplete(AsyncEvent) will be delayed) until after the container-initiated dispatch has returned to the container.

Specified by:

complete in interface javax.servlet.AsyncContext

dispatch

public void dispatch()

Description copied from interface: javax.servlet.AsyncContext

Dispatches the request and response objects of this AsyncContext to the servlet container.

If the asynchronous cycle was started with ServletRequest.startAsync(ServletRequest, ServletResponse), and the request passed is an instance of HttpServletRequest, then the dispatch is to the URI returned by HttpServletRequest.getRequestURI(). Otherwise, the dispatch is to the URI of the request when it was last dispatched by the container.

The following sequence illustrates how this will work:

 // REQUEST dispatch to /url/A
 AsyncContext ac = request.startAsync();
 ...
 ac.dispatch(); // ASYNC dispatch to /url/A
 
 // FORWARD dispatch to /url/B
 getRequestDispatcher("/url/B").forward(request,response);
 // Start async operation from within the target of the FORWARD
 // dispatch
 ac = request.startAsync();
 ...
 ac.dispatch(); // ASYNC dispatch to /url/A
 
 // FORWARD dispatch to /url/B
 getRequestDispatcher("/url/B").forward(request,response);
 // Start async operation from within the target of the FORWARD
 // dispatch
 ac = request.startAsync(request,response);
 ...
 ac.dispatch(); // ASYNC dispatch to /url/B
 

This method returns immediately after passing the request and response objects to a container managed thread, on which the dispatch operation will be performed.

The dispatcher type of the request is set to DispatcherType.ASYNC. Unlike forward dispatches, the response buffer and headers will not be reset, and it is legal to dispatch even if the response has already been committed.

Control over the request and response is delegated to the dispatch target, and the response will be closed when the dispatch target has completed execution, unless ServletRequest.startAsync() or ServletRequest.startAsync(ServletRequest, ServletResponse) are called.

Any errors or exceptions that may occur during the execution of this method must be caught and handled by the container, as follows:

1. Invoke, at their onError method, all AsyncListener instances registered with the ServletRequest for which this AsyncContext was created, and make the caught Throwable available via AsyncEvent.getThrowable().
2. If none of the listeners called AsyncContext.complete() or any of the AsyncContext.dispatch() methods, perform an error dispatch with a status code equal to HttpServletResponse.SC_INTERNAL_SERVER_ERROR, and make the above Throwable available as the value of the RequestDispatcher.ERROR_EXCEPTION request attribute.
3. If no matching error page was found, or the error page did not call AsyncContext.complete() or any of the AsyncContext.dispatch() methods, call AsyncContext.complete().

There can be at most one asynchronous dispatch operation per asynchronous cycle, which is started by a call to one of the ServletRequest.startAsync() methods. Any attempt to perform an additional asynchronous dispatch operation within the same asynchronous cycle will result in an IllegalStateException. If startAsync is subsequently called on the dispatched request, then any of the dispatch or AsyncContext.complete() methods may be called.

Specified by:

dispatch in interface javax.servlet.AsyncContext

See Also:

ServletRequest.getDispatcherType()

dispatch

public void dispatch(java.lang.String path)

Description copied from interface: javax.servlet.AsyncContext

Dispatches the request and response objects of this AsyncContext to the given path.

The path parameter is interpreted in the same way as in ServletRequest.getRequestDispatcher(String), within the scope of the ServletContext from which this AsyncContext was initialized.

All path related query methods of the request must reflect the dispatch target, while the original request URI, context path, path info, servlet path, and query string may be recovered from the AsyncContext.ASYNC_REQUEST_URI, AsyncContext.ASYNC_CONTEXT_PATH, AsyncContext.ASYNC_PATH_INFO, AsyncContext.ASYNC_SERVLET_PATH, and AsyncContext.ASYNC_QUERY_STRING attributes of the request. These attributes will always reflect the original path elements, even under repeated dispatches.

There can be at most one asynchronous dispatch operation per asynchronous cycle, which is started by a call to one of the ServletRequest.startAsync() methods. Any attempt to perform an additional asynchronous dispatch operation within the same asynchronous cycle will result in an IllegalStateException. If startAsync is subsequently called on the dispatched request, then any of the dispatch or AsyncContext.complete() methods may be called.

See AsyncContext.dispatch() for additional details, including error handling.

Specified by:

dispatch in interface javax.servlet.AsyncContext

Parameters:

path - the path of the dispatch target, scoped to the ServletContext from which this AsyncContext was initialized

See Also:

ServletRequest.getDispatcherType()

dispatch

public void dispatch(javax.servlet.ServletContext servletContext,
                     java.lang.String path)

Description copied from interface: javax.servlet.AsyncContext

Dispatches the request and response objects of this AsyncContext to the given path scoped to the given context.

The path parameter is interpreted in the same way as in ServletRequest.getRequestDispatcher(String), except that it is scoped to the given context.

All path related query methods of the request must reflect the dispatch target, while the original request URI, context path, path info, servlet path, and query string may be recovered from the AsyncContext.ASYNC_REQUEST_URI, AsyncContext.ASYNC_CONTEXT_PATH, AsyncContext.ASYNC_PATH_INFO, AsyncContext.ASYNC_SERVLET_PATH, and AsyncContext.ASYNC_QUERY_STRING attributes of the request. These attributes will always reflect the original path elements, even under repeated dispatches.

There can be at most one asynchronous dispatch operation per asynchronous cycle, which is started by a call to one of the ServletRequest.startAsync() methods. Any attempt to perform an additional asynchronous dispatch operation within the same asynchronous cycle will result in an IllegalStateException. If startAsync is subsequently called on the dispatched request, then any of the dispatch or AsyncContext.complete() methods may be called.

See AsyncContext.dispatch() for additional details, including error handling.

Specified by:

dispatch in interface javax.servlet.AsyncContext

Parameters:

servletContext - the ServletContext of the dispatch target

path - the path of the dispatch target, scoped to the given ServletContext

See Also:

ServletRequest.getDispatcherType()

getRequest

public javax.servlet.ServletRequest getRequest()

Description copied from interface: javax.servlet.AsyncContext

Gets the request that was used to initialize this AsyncContext by calling ServletRequest.startAsync() or ServletRequest.startAsync(ServletRequest, ServletResponse).

Specified by:

getRequest in interface javax.servlet.AsyncContext

Returns:

the request that was used to initialize this AsyncContext

getResponse

public javax.servlet.ServletResponse getResponse()

Description copied from interface: javax.servlet.AsyncContext

Gets the response that was used to initialize this AsyncContext by calling ServletRequest.startAsync() or ServletRequest.startAsync(ServletRequest, ServletResponse).

Specified by:

getResponse in interface javax.servlet.AsyncContext

Returns:

the response that was used to initialize this AsyncContext

hasOriginalRequestAndResponse

public boolean hasOriginalRequestAndResponse()

Description copied from interface: javax.servlet.AsyncContext

Checks if this AsyncContext was initialized with the original or application-wrapped request and response objects.

This information may be used by filters invoked in the outbound direction, after a request was put into asynchronous mode, to determine whether any request and/or response wrappers that they added during their inbound invocation need to be preserved for the duration of the asynchronous operation, or may be released.

Specified by:

hasOriginalRequestAndResponse in interface javax.servlet.AsyncContext

Returns:

true if this AsyncContext was initialized with the original request and response objects by calling ServletRequest.startAsync(), or if it was initialized by calling ServletRequest.startAsync(ServletRequest, ServletResponse), and neither the ServletRequest nor ServletResponse arguments carried any application-provided wrappers; false otherwise

start

public void start(java.lang.Runnable runnable)

Description copied from interface: javax.servlet.AsyncContext

Causes the container to dispatch a thread, possibly from a managed thread pool, to run the specified Runnable. The container may propagate appropriate contextual information to the Runnable.

Specified by:

start in interface javax.servlet.AsyncContext

Parameters:

runnable - the asynchronous handler

isReady

public boolean isReady()

done

public void done()

setRequestAndResponse

public void setRequestAndResponse(javax.servlet.ServletRequest servletRequest,
                                  javax.servlet.ServletResponse servletResponse)

getServletContext

public javax.servlet.ServletContext getServletContext()

getPath

public java.lang.String getPath()

getUseAttributes

public boolean getUseAttributes()

getRunnable

public java.lang.Runnable getRunnable()

reset

public void reset()

getAsyncListeners

public java.util.Map<javax.servlet.AsyncListener,Request.AsyncListenerRegistration> getAsyncListeners()

addListener

public void addListener(javax.servlet.AsyncListener listener,
                        javax.servlet.ServletRequest servletRequest,
                        javax.servlet.ServletResponse servletResponse)

Description copied from interface: javax.servlet.AsyncContext

Registers the given AsyncListener with the most recent asynchronous cycle that was started by a call to one of the ServletRequest.startAsync() methods.

The given AsyncListener will receive an AsyncEvent when the asynchronous cycle completes successfully, times out, or results in an error.

AsyncListener instances will be notified in the order in which they were added.

The given ServletRequest and ServletResponse objects will be made available to the given AsyncListener via the getSuppliedRequest and getSuppliedResponse methods, respectively, of the AsyncEvent delivered to it. These objects should not be read from or written to, respectively, at the time the AsyncEvent is delivered, because additional wrapping may have occurred since the given AsyncListener was registered, but may be used in order to release any resources associated with them.

Specified by:

addListener in interface javax.servlet.AsyncContext

Parameters:

listener - the AsyncListener to be registered

servletRequest - the ServletRequest that will be included in the AsyncEvent

servletResponse - the ServletResponse that will be included in the AsyncEvent

addListener

public void addListener(javax.servlet.AsyncListener listener)

Description copied from interface: javax.servlet.AsyncContext

Registers the given AsyncListener with the most recent asynchronous cycle that was started by a call to one of the ServletRequest.startAsync() methods.

The given AsyncListener will receive an AsyncEvent when the asynchronous cycle completes successfully, times out, or results in an error.

AsyncListener instances will be notified in the order in which they were added.

Specified by:

addListener in interface javax.servlet.AsyncContext

Parameters:

listener - the AsyncListener to be registered

getTimeout

public long getTimeout()

Description copied from interface: javax.servlet.AsyncContext

Gets the timeout (in milliseconds) for this AsyncContext.

This method returns the container's default timeout for asynchronous operations, or the timeout value passed to the most recent invocation of AsyncContext.setTimeout(long).

A timeout value of zero or less indicates no timeout.

Specified by:

getTimeout in interface javax.servlet.AsyncContext

Returns:

the timeout in milliseconds

setTimeout

public void setTimeout(long timeout)

Description copied from interface: javax.servlet.AsyncContext

Sets the timeout (in milliseconds) for this AsyncContext.

The timeout applies to this AsyncContext once the container-initiated dispatch during which one of the ServletRequest.startAsync() methods was called has returned to the container.

The timeout will expire if neither the AsyncContext.complete() method nor any of the dispatch methods are called. A timeout value of zero or less indicates no timeout.

If AsyncContext.setTimeout(long) is not called, then the container's default timeout, which is available via a call to AsyncContext.getTimeout(), will apply.

Specified by:

setTimeout in interface javax.servlet.AsyncContext

Parameters:

timeout - the timeout in milliseconds

createListener

public <T extends javax.servlet.AsyncListener> T createListener(java.lang.Class<T> clazz)
                                                     throws javax.servlet.ServletException

Description copied from interface: javax.servlet.AsyncContext

Instantiates the given AsyncListener class.

The returned AsyncListener instance may be further customized before it is registered with this AsyncContext via a call to one of the addListener methods.

The given AsyncListener class must define a zero argument constructor, which is used to instantiate it.

This method supports resource injection if the given clazz represents a Managed Bean. See the Java EE platform and JSR 299 specifications for additional details about Managed Beans and resource injection.

This method supports any annotations applicable to AsyncListener.

Specified by:

createListener in interface javax.servlet.AsyncContext

Parameters:

clazz - the AsyncListener class to instantiate

Returns:

the new AsyncListener instance

Throws:

javax.servlet.ServletException - if the given clazz fails to be instantiated