Class ExchangeRateReader

java.lang.Object

org.episteme.core.io.AbstractResourceReader<Real>

org.episteme.social.economics.loaders.ExchangeRateReader

All Implemented Interfaces:

ResourceIO<Real>, ResourceReader<Real>

public class ExchangeRateReader
extends AbstractResourceReader<Real>

Modern currency exchange rate reader using free public APIs.

Supports multiple data sources:

• ECB (European Central Bank) - Free, no API key required, updates daily
• Frankfurter - Free, based on ECB data, no API key required
• ExchangeRate-API - Free tier with 1500 requests/month

This replaces the deprecated OandaRateLoader.

Since:

1.0

Author:

Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ExchangeRateReader.Source

Constructor Summary

Constructors

Constructor	Description
ExchangeRateReader()
ExchangeRateReader(ExchangeRateReader.Source source)

Method Summary

Modifier and Type	Method	Description
Real	convert(Real amount, String from, String to)	Converts an amount between currencies.
Map<String,Real>	getAllRates(String baseCurrency)	Gets all available rates for a base currency.
String	getCategory()	Returns the category for grouping.
String	getDescription()	Returns a short description of this resource handler.
String	getLongDescription()	Returns a long description of this resource handler.
String	getName()	Returns the display name of this resource handler.
String	getResourcePath()	Returns the base path where this resource is located.
Class<Real>	getResourceType()	Returns the type of resource.
String[]	getSupportedVersions()	Returns the supported versions of the format this reader/writer handles.
protected Real	loadFromSource(String currencyPairId)	Loads an exchange rate for a currency pair.

Methods inherited from class AbstractResourceReader

clearCache, getMiniCatalog, getSampleDataPath, isUsingFallback, load, loadAll, loadAllFromSource, loadFromFallback, loadFromInputStream, setCacheEnabled

Methods inherited from class Object

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

Methods inherited from interface ResourceIO

getExpectedResourceFiles, getSupportedExtensions, isFileBased, isOutput

Methods inherited from interface ResourceReader

isInput

Constructor Details

ExchangeRateReader

public ExchangeRateReader()

ExchangeRateReader

public ExchangeRateReader(ExchangeRateReader.Source source)

Method Details

getName

public String getName()

Description copied from interface: ResourceIO

Returns the display name of this resource handler. MUST be implemented with I18N support.

Returns:

the display name

getCategory

public String getCategory()

Description copied from interface: ResourceIO

Returns the category for grouping. MUST be implemented with I18N support.

Returns:

the category name

getDescription

public String getDescription()

Description copied from interface: ResourceIO

Returns a short description of this resource handler. MUST be implemented with I18N support.

Returns:

the description

getLongDescription

public String getLongDescription()

Description copied from interface: ResourceIO

Returns a long description of this resource handler. MUST be implemented with I18N support.

Returns:

the long description

getResourcePath

public String getResourcePath()

Description copied from interface: ResourceIO

Returns the base path where this resource is located.

getResourceType

public Class<Real> getResourceType()

Description copied from interface: ResourceIO

Returns the type of resource.

getSupportedVersions

public String[] getSupportedVersions()

Description copied from interface: ResourceIO

Returns the supported versions of the format this reader/writer handles.

Each implementation MUST override this method to declare which versions of the underlying format are supported. The returned array should contain version strings in the format's standard notation (e.g., "3.0", "2.1", "Level 3 Version 2").

Examples:

• MathML: {"3.0", "2.0"}
• SBML: {"Level 3 Version 2", "Level 3 Version 1", "Level 2 Version 5"}
• PhyloXML: {"1.10", "1.00"}

Returns:

array of supported version strings, never null (empty array if version-agnostic)

loadFromSource

protected Real loadFromSource(String currencyPairId)
                       throws Exception

Loads an exchange rate for a currency pair.

Specified by:

loadFromSource in class AbstractResourceReader<Real>

Parameters:

currencyPairId - Format: "FROM/TO" (e.g., "USD/EUR" or "EUR/JPY")

Returns:

The exchange rate (how many target units per 1 source unit)

Throws:

Exception

getAllRates

public Map<String,Real> getAllRates(String baseCurrency)
                             throws Exception

Gets all available rates for a base currency.

Parameters:

baseCurrency - The base currency code (e.g., "USD", "EUR")

Returns:

Map of currency codes to exchange rates

Throws:

Exception

convert

public Real convert(Real amount,
 String from,
 String to)
             throws Exception

Converts an amount between currencies.

Parameters:

amount - The amount to convert

from - Source currency code

to - Target currency code

Returns:

The converted amount

Throws:

Exception