com.wallee.android.sdk.request.icon

Class AbstractIconCache

java.lang.Object

com.wallee.android.sdk.request.icon.AbstractIconCache

All Implemented Interfaces:

IconCache

Direct Known Subclasses:

InMemoryIconCache

public abstract class AbstractIconCache
extends java.lang.Object
implements IconCache

Abstract implementation of IconCache which provides the loading of multiple icons at once. This will be most likely always the same independent of the cache strategy.

Additionally it implements strategies to avoid loading the same icon multiple times by identify the same payment methods even when they are different object.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AbstractIconCache.CacheKey The cache key uses the fact that the payment method configuration is uniquely identifiable by the version and id.

Field Summary

Fields inherited from interface com.wallee.android.sdk.request.icon.IconCache

DEFAULT_ICON_LOADING_TIMEOUT

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractIconCache(long timeout) Constructs a new cache with the specified timeout for loading multiple icons.

Method Summary

Modifier and Type	Method and Description
void	fetchIcons(java.util.Collection<PaymentMethodConfiguration> paymentMethodConfigurations, AsynchronousCallback<java.util.Map<PaymentMethodConfiguration,PaymentMethodIcon>> callback) This method fetches for a collection of PaymentMethodConfiguration the associated icons.
void	loadIcon(PaymentMethodConfiguration paymentMethodConfiguration, RequestCallback<PaymentMethodIcon> callback) This method is invoked when for the methodConfiguration the images should be downloaded.
protected abstract PaymentMethodIcon	lookupInLocalCache(AbstractIconCache.CacheKey paymentMethodConfiguration) This method is invoked to try to load the icon from the local cache.
protected abstract void	lookupInRemoteServer(AbstractIconCache.CacheKey paymentMethodConfiguration, RequestCallback<PaymentMethodIcon> callback) This method has to query the remote host to fetch the icon.
protected abstract void	putInLocalCache(AbstractIconCache.CacheKey paymentMethodConfiguration, PaymentMethodIcon icon) This method is invoked to persist an entry into the local cache.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractIconCache

protected AbstractIconCache(long timeout)

Constructs a new cache with the specified timeout for loading multiple icons.

Parameters:

timeout - the timeout which cannot be exceeded when multiple icons are loaded. The time is in milliseconds.

Method Detail

lookupInRemoteServer

protected abstract void lookupInRemoteServer(AbstractIconCache.CacheKey paymentMethodConfiguration,
                                             RequestCallback<PaymentMethodIcon> callback)

This method has to query the remote host to fetch the icon.

This method has to be implemented in a thread-safe manner.

Parameters:

paymentMethodConfiguration - the payment method configuration for which the icon should be fetched for.

callback - the callback which has to be invoked once the loading has been completed.

lookupInLocalCache

protected abstract PaymentMethodIcon lookupInLocalCache(AbstractIconCache.CacheKey paymentMethodConfiguration)

This method is invoked to try to load the icon from the local cache. The method may return null when the entry does not exists.

This method has to be implemented in a thread-safe manner.

Parameters:

paymentMethodConfiguration - the payment method configuration for which the icon should be looked up.

Returns:

the icon instance or null when it does not exists.

putInLocalCache

protected abstract void putInLocalCache(AbstractIconCache.CacheKey paymentMethodConfiguration,
                                        PaymentMethodIcon icon)

This method is invoked to persist an entry into the local cache.

This method has to be implemented in a thread-safe manner.

Parameters:

paymentMethodConfiguration - the payment method configuration for which the icon should be stored for.

icon - the icon which should be stored.

loadIcon

public void loadIcon(PaymentMethodConfiguration paymentMethodConfiguration,
                     RequestCallback<PaymentMethodIcon> callback)

Description copied from interface: IconCache

This method is invoked when for the methodConfiguration the images should be downloaded.

The implementor has to make sure that a parallel invocation of this method does not cause a memory leak. This means that a storage of the result should be implemented in a way that duplicate requests get detected and handled properly. For example by using a ConcurrentMap or some kind of AtomicReference.

The URL from which the icon should be downloaded from can be found on PaymentMethodConfiguration.getResolvedImageUrl().

There is also a IconRequestManager which helps with the invocation of the remote server.

Specified by:

loadIcon in interface IconCache

Parameters:

paymentMethodConfiguration - the payment method configuration for which the icon should be provided for.

callback - the callback which should be invoked once the icon has been loaded either form the source or from the cache.

fetchIcons

public final void fetchIcons(java.util.Collection<PaymentMethodConfiguration> paymentMethodConfigurations,
                             AsynchronousCallback<java.util.Map<PaymentMethodConfiguration,PaymentMethodIcon>> callback)

Description copied from interface: IconCache

This method fetches for a collection of PaymentMethodConfiguration the associated icons.

The method will stop after a specified timeout. The resulting map will have no entry for those which could not be loaded within the timeout.

Specified by:

fetchIcons in interface IconCache

Parameters:

paymentMethodConfigurations - the configurations for which the icons should be loaded for.

callback - the callback which is invoked once the loading has completed or the timeout has been reached.