oracle.adf.view.rich.model

Class AsyncFetcher

java.lang.Object

oracle.adf.view.rich.model.AsyncFetcher

public abstract class AsyncFetcher
extends Object

Class vended by AsyncFetch for performing data fetch operations off of the Request thread.

See Also:

AsyncFetch

Constructor Summary

Constructors

Constructor and Description
AsyncFetcher()

Method Summary

Modifier and Type	Method and Description
Object	fetch(AsyncFetch model, Object fetchConstraint) Deprecated. Replaced by fetch(AsyncFetch, Object, Object)
abstract Object	fetch(AsyncFetch model, Object fetchConstraint, Object fetchContext) Tells the model to fetch the data specified by the fetchConstraint.
Object	getFetchContext(AsyncFetch model, Object fetchConstraint) The context object returned by this method will be passed to the fetch() method This method is always called on a request thread
abstract boolean	isFetched(AsyncFetch model, Object fetchConstraint) Returns true if the fetchConstraint is of a type supported by the model and all of the data specified by the fetchConstraint is either in memory or unavailable for fetching.

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncFetcher

public AsyncFetcher()

Method Detail

isFetched

public abstract boolean isFetched(AsyncFetch model,
                                  Object fetchConstraint)

Returns true if the fetchConstraint is of a type supported by the model and all of the data specified by the fetchConstraint is either in memory or unavailable for fetching. An example where the data is unavailable would be a fetchConstraint that specified a row index beyond the model's row count.

If determining whether the fetchConstraint is cached in memory is extremely expensive, the implementation should return false.

Parameters:

model - AsyncFetch model to ask if the fetchConstraint is already available in memory

fetchConstraint - constraint specifying which data to fetch

Returns:

true if the fetchConstraint is already available in memory for this model.

See Also:

fetch(AsyncFetch, Object, Object)

getFetchContext

public Object getFetchContext(AsyncFetch model,
                              Object fetchConstraint)

The context object returned by this method will be passed to the fetch() method This method is always called on a request thread

Parameters:

model - AsyncFetch model to ask if the fetchConstraint is already available in memory

fetchConstraint - constraint specifying which data to fetch

Returns:

context object

See Also:

fetch(AsyncFetch, Object, Object)

fetch

public abstract Object fetch(AsyncFetch model,
                             Object fetchConstraint,
                             Object fetchContext)
                      throws InterruptedException

Tells the model to fetch the data specified by the fetchConstraint. This data will subsequently be accessed on the request thread.

The method will not return until all rows in the range have been fetched and cached.

This method may be called on a non-Request thread and the FacesContext may not be available.

Parameters:

model - AsyncFetch model to fetch the data from

fetchConstraint - Constraint specifying which data to fetch

fetchContext - a context object provided by the getFetchContext() call

Returns:

the number of Objects in the specified range that are now available

Throws:

InterruptedException - if the operation is interuppted.

See Also:

isFetched(oracle.adf.view.rich.model.AsyncFetch, java.lang.Object), getFetchContext(oracle.adf.view.rich.model.AsyncFetch, java.lang.Object)

fetch

@Deprecated
public Object fetch(AsyncFetch model,
                                Object fetchConstraint)
                         throws InterruptedException

Deprecated. Replaced by fetch(AsyncFetch, Object, Object)

Parameters:

model - AsyncFetch model to fetch the data from

fetchConstraint - Constraint specifying which data to fetch

Returns:

the fetched object

Throws:

InterruptedException - if the operation is interuppted.