de.richtercloud.reflection.form.builder.components.money

Class FailsafeAmountMoneyExchangeRateRetriever

java.lang.Object

de.richtercloud.reflection.form.builder.components.money.FailsafeAmountMoneyExchangeRateRetriever

All Implemented Interfaces:

AmountMoneyExchangeRateRetriever

public class FailsafeAmountMoneyExchangeRateRetriever
extends Object
implements AmountMoneyExchangeRateRetriever

Has multiple AmountMoneyExchangeRateRetrievers available for retrieval and wraps calls to retrieveExchangeRate(org.jscience.economics.money.Currency) in a try-catch block and delegates to the next candidate if the call to the preceeding fails. Supported currencies are those supported by at least one AmountMoneyExchangeRateRetriever which returns a result. That's necessary because otherwise one failing AmountMoneyExchangeRateRetriever causes the FailsafeAmountMoneyExchangeRateRetriever to fail which isn't intended. Note that this doesn't make the call really, but only almost failsafe. The name is still fine imo.

Author:

richter

Field Summary

Fields

Modifier and Type	Field and Description
static int	AVAILABLE_RETRIEVER_MIN_DEFAULT

Constructor Summary

Constructors

Constructor and Description
FailsafeAmountMoneyExchangeRateRetriever(File cacheFileDir)
FailsafeAmountMoneyExchangeRateRetriever(File cacheFileDir, long fileCacheExpirationMillis)
FailsafeAmountMoneyExchangeRateRetriever(int availableRetrieverMin, File cacheFileDir, long fileCacheExpirationMillis)
FailsafeAmountMoneyExchangeRateRetriever(int availableRetrieverMin, Set<AmountMoneyExchangeRateRetriever> fallbackRetrievers)
FailsafeAmountMoneyExchangeRateRetriever(Set<AmountMoneyExchangeRateRetriever> fallbackRetrievers)

Method Summary

Modifier and Type	Method and Description
Set<org.jscience.economics.money.Currency>	getSupportedCurrencies() In order to be really failsafe this method only returns currencies which are supported by all used exchange rate retrievers.
void	retrieveExchangeRate(org.jscience.economics.money.Currency currency) Sets the exchangeRate property on the passed currency relative to a reference currency.

Methods inherited from class java.lang.Object

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

Field Detail

AVAILABLE_RETRIEVER_MIN_DEFAULT

public static final int AVAILABLE_RETRIEVER_MIN_DEFAULT

See Also:

Constant Field Values

Constructor Detail

FailsafeAmountMoneyExchangeRateRetriever

public FailsafeAmountMoneyExchangeRateRetriever(File cacheFileDir)
                                         throws IOException

Throws:

IOException

FailsafeAmountMoneyExchangeRateRetriever

public FailsafeAmountMoneyExchangeRateRetriever(File cacheFileDir,
                                                long fileCacheExpirationMillis)
                                         throws IOException

Throws:

IOException

FailsafeAmountMoneyExchangeRateRetriever

public FailsafeAmountMoneyExchangeRateRetriever(int availableRetrieverMin,
                                                File cacheFileDir,
                                                long fileCacheExpirationMillis)
                                         throws IOException

Parameters:

availableRetrieverMin - the minimum number of available retrievers which are tried

cacheFileDir - Since FailsafeAmountMoneyExchangeRateRetriever will manage multiple possibly caching retrievers, a directory needs to be used for cache files.

fileCacheExpirationMillis - the expiraton time of the file cache in milliseconds

Throws:

IOException - if the creation of cacheFileDir fails

FailsafeAmountMoneyExchangeRateRetriever

public FailsafeAmountMoneyExchangeRateRetriever(Set<AmountMoneyExchangeRateRetriever> fallbackRetrievers)

FailsafeAmountMoneyExchangeRateRetriever

public FailsafeAmountMoneyExchangeRateRetriever(int availableRetrieverMin,
                                                Set<AmountMoneyExchangeRateRetriever> fallbackRetrievers)

Method Detail

getSupportedCurrencies

public Set<org.jscience.economics.money.Currency> getSupportedCurrencies()
                                                                  throws AmountMoneyExchangeRateRetrieverException

In order to be really failsafe this method only returns currencies which are supported by all used exchange rate retrievers.

Specified by:

getSupportedCurrencies in interface AmountMoneyExchangeRateRetriever

Returns:

the set of supported currencies

Throws:

AmountMoneyExchangeRateRetrieverException - if an exception unrelated to a network failure or missing network connection occured

retrieveExchangeRate

public void retrieveExchangeRate(org.jscience.economics.money.Currency currency)
                          throws AmountMoneyExchangeRateRetrieverException

Description copied from interface: AmountMoneyExchangeRateRetriever

Sets the exchangeRate property on the passed currency relative to a reference currency.

Specified by:

retrieveExchangeRate in interface AmountMoneyExchangeRateRetriever

Parameters:

currency - the currency to retrieve for

Throws:

AmountMoneyExchangeRateRetrieverException - if an exception unrelated to a network failure or missing network connection occured