Java tutorial
/** * Copyright (C) 2015 - present by OpenGamma Inc. and the OpenGamma group of companies * * Please see distribution for license. */ package com.opengamma.strata.loader.csv; import static java.util.stream.Collectors.toList; import java.time.LocalDate; import java.util.Arrays; import java.util.Collection; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import java.util.function.Predicate; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableMap.Builder; import com.google.common.io.CharSource; import com.opengamma.strata.basics.currency.CurrencyPair; import com.opengamma.strata.basics.currency.FxRate; import com.opengamma.strata.collect.Messages; import com.opengamma.strata.collect.io.CsvFile; import com.opengamma.strata.collect.io.CsvRow; import com.opengamma.strata.collect.io.ResourceLocator; import com.opengamma.strata.data.FxRateId; /** * Loads a set of FX rates into memory from CSV resources. * <p> * The rates are expected to be in a CSV format, with the following header row:<br /> * {@code Valuation Date, Currency Pair, Value}. * <ul> * <li>The 'Valuation Date' column provides the valuation date, allowing data from different * days to be stored in the same file * <li>The 'Currency Pair' column is the currency pair in the format 'EUR/USD'. * <li>The 'Value' column is the value of the rate. * </ul> * <p> * Each file may contain entries for many different dates. * <p> * For example: * <pre> * Valuation Date, Currency Pair, Value * 2014-01-22, EUR/USD, 1.10 * 2014-01-22, GBP/USD, 1.50 * 2014-01-23, EUR/USD, 1.11 * </pre> * Note that Microsoft Excel prefers the CSV file to have no space after the comma. */ public final class FxRatesCsvLoader { // CSV column headers private static final String DATE_FIELD = "Valuation Date"; private static final String CURRENCY_PAIR_FIELD = "Currency Pair"; private static final String VALUE_FIELD = "Value"; //------------------------------------------------------------------------- /** * Loads one or more CSV format FX rate files for a specific date. * <p> * Only those rates that match the specified date will be loaded. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param marketDataDate the date to load * @param resources the CSV resources * @return the loaded FX rates, mapped by {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<FxRateId, FxRate> load(LocalDate marketDataDate, ResourceLocator... resources) { return load(marketDataDate, Arrays.asList(resources)); } /** * Loads one or more CSV format FX rate files for a specific date. * <p> * Only those rates that match the specified date will be loaded. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param marketDataDate the date to load * @param resources the CSV resources * @return the loaded FX rates, mapped by {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<FxRateId, FxRate> load(LocalDate marketDataDate, Collection<ResourceLocator> resources) { Collection<CharSource> charSources = resources.stream().map(r -> r.getCharSource()).collect(toList()); return parse(d -> marketDataDate.equals(d), charSources).getOrDefault(marketDataDate, ImmutableMap.of()); } //------------------------------------------------------------------------- /** * Loads one or more CSV format FX rate files for a set of dates. * <p> * Only those rates that match one of the specified dates will be loaded. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param marketDataDates the set of dates to load * @param resources the CSV resources * @return the loaded FX rates, mapped by {@link LocalDate} and {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<LocalDate, ImmutableMap<FxRateId, FxRate>> load(Set<LocalDate> marketDataDates, ResourceLocator... resources) { return load(marketDataDates, Arrays.asList(resources)); } /** * Loads one or more CSV format FX rate files for a set of dates. * <p> * Only those rates that match one of the specified dates will be loaded. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param marketDataDates the dates to load * @param resources the CSV resources * @return the loaded FX rates, mapped by {@link LocalDate} and {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<LocalDate, ImmutableMap<FxRateId, FxRate>> load(Set<LocalDate> marketDataDates, Collection<ResourceLocator> resources) { Collection<CharSource> charSources = resources.stream().map(r -> r.getCharSource()).collect(toList()); return parse(d -> marketDataDates.contains(d), charSources); } //------------------------------------------------------------------------- /** * Loads one or more CSV format FX rate files. * <p> * All dates that are found will be returned. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param resources the CSV resources * @return the loaded FX rates, mapped by {@link LocalDate} and {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<LocalDate, ImmutableMap<FxRateId, FxRate>> loadAllDates( ResourceLocator... resources) { return loadAllDates(Arrays.asList(resources)); } /** * Loads one or more CSV format FX rate files. * <p> * All dates that are found will be returned. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param resources the CSV resources * @return the loaded FX rates, mapped by {@link LocalDate} and {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<LocalDate, ImmutableMap<FxRateId, FxRate>> loadAllDates( Collection<ResourceLocator> resources) { Collection<CharSource> charSources = resources.stream().map(r -> r.getCharSource()).collect(toList()); return parse(d -> true, charSources); } //------------------------------------------------------------------------- /** * Parses one or more CSV format FX rate files. * <p> * A predicate is specified that is used to filter the dates that are returned. * This could match a single date, a set of dates or all dates. * <p> * If the files contain a duplicate entry an exception will be thrown. * * @param datePredicate the predicate used to select the dates * @param charSources the CSV character sources * @return the loaded FX rates, mapped by {@link LocalDate} and {@linkplain FxRateId rate ID} * @throws IllegalArgumentException if the files contain a duplicate entry */ public static ImmutableMap<LocalDate, ImmutableMap<FxRateId, FxRate>> parse(Predicate<LocalDate> datePredicate, Collection<CharSource> charSources) { // builder ensures keys can only be seen once Map<LocalDate, ImmutableMap.Builder<FxRateId, FxRate>> mutableMap = new HashMap<>(); for (CharSource charSource : charSources) { parseSingle(datePredicate, charSource, mutableMap); } ImmutableMap.Builder<LocalDate, ImmutableMap<FxRateId, FxRate>> builder = ImmutableMap.builder(); for (Entry<LocalDate, Builder<FxRateId, FxRate>> entry : mutableMap.entrySet()) { builder.put(entry.getKey(), entry.getValue().build()); } return builder.build(); } // loads a single CSV file, filtering by date private static void parseSingle(Predicate<LocalDate> datePredicate, CharSource resource, Map<LocalDate, ImmutableMap.Builder<FxRateId, FxRate>> mutableMap) { try { CsvFile csv = CsvFile.of(resource, true); for (CsvRow row : csv.rows()) { String dateText = row.getField(DATE_FIELD); LocalDate date = LocalDate.parse(dateText); if (datePredicate.test(date)) { String currencyPairStr = row.getField(CURRENCY_PAIR_FIELD); String valueStr = row.getField(VALUE_FIELD); CurrencyPair currencyPair = CurrencyPair.parse(currencyPairStr); double value = Double.valueOf(valueStr); ImmutableMap.Builder<FxRateId, FxRate> builderForDate = mutableMap.computeIfAbsent(date, k -> ImmutableMap.builder()); builderForDate.put(FxRateId.of(currencyPair), FxRate.of(currencyPair, value)); } } } catch (RuntimeException ex) { throw new IllegalArgumentException( Messages.format("Error processing resource as CSV file: {}", resource), ex); } } //------------------------------------------------------------------------- /** * Restricted constructor. */ private FxRatesCsvLoader() { } }