solr/core/src/java/org/apache/solr/schema/FileExchangeRateProvider.java - lucene-solr - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.apache.solr.schema;

 import java.io.IOException;
 import java.lang.invoke.MethodHandles;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;

 import javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpressionException;
 import javax.xml.xpath.XPathFactory;

 import org.apache.lucene.analysis.util.ResourceLoader;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.util.SafeXMLParsing;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.NamedNodeMap;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;

 /**
  * Configuration for currency. Provides currency exchange rates.
  */
 public class FileExchangeRateProvider implements ExchangeRateProvider {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

   protected static final String PARAM_CURRENCY_CONFIG       = "currencyConfig";

   // Exchange rate map, maps Currency Code -> Currency Code -> Rate
   private Map<String, Map<String, Double>> rates = new HashMap<>();

   private String currencyConfigFile;
   private ResourceLoader loader;

   /**
    * Returns the currently known exchange rate between two currencies. If a direct rate has been loaded,
    * it is used. Otherwise, if a rate is known to convert the target currency to the source, the inverse
    * exchange rate is computed.
    *
    * @param sourceCurrencyCode The source currency being converted from.
    * @param targetCurrencyCode The target currency being converted to.
    * @return The exchange rate.
    * @throws SolrException if the requested currency pair cannot be found
    */
   @Override
   public double getExchangeRate(String sourceCurrencyCode, String targetCurrencyCode) {
     if (sourceCurrencyCode == null || targetCurrencyCode == null) {
       throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Cannot get exchange rate; currency was null.");
     }

     if (sourceCurrencyCode.equals(targetCurrencyCode)) {
       return 1.0;
     }

     Double directRate = lookupRate(sourceCurrencyCode, targetCurrencyCode);

     if (directRate != null) {
       return directRate;
     }

     Double symmetricRate = lookupRate(targetCurrencyCode, sourceCurrencyCode);

     if (symmetricRate != null) {
       return 1.0 / symmetricRate;
     }

     throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "No available conversion rate between " + sourceCurrencyCode + " to " + targetCurrencyCode);
   }

   /**
    * Looks up the current known rate, if any, between the source and target currencies.
    *
    * @param sourceCurrencyCode The source currency being converted from.
    * @param targetCurrencyCode The target currency being converted to.
    * @return The exchange rate, or null if no rate has been registered.
    */
   private Double lookupRate(String sourceCurrencyCode, String targetCurrencyCode) {
     Map<String, Double> rhs = rates.get(sourceCurrencyCode);

     if (rhs != null) {
       return rhs.get(targetCurrencyCode);
     }

     return null;
   }

   /**
    * Registers the specified exchange rate.
    *
    * @param ratesMap           The map to add rate to
    * @param sourceCurrencyCode The source currency.
    * @param targetCurrencyCode The target currency.
    * @param rate               The known exchange rate.
    */
   private void addRate(Map<String, Map<String, Double>> ratesMap, String sourceCurrencyCode, String targetCurrencyCode, double rate) {
     Map<String, Double> rhs = ratesMap.get(sourceCurrencyCode);

     if (rhs == null) {
       rhs = new HashMap<>();
       ratesMap.put(sourceCurrencyCode, rhs);
     }

     rhs.put(targetCurrencyCode, rate);
   }

   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
     if (o == null || getClass() != o.getClass()) return false;

     FileExchangeRateProvider that = (FileExchangeRateProvider) o;

     return !(rates != null ? !rates.equals(that.rates) : that.rates != null);
   }

   @Override
   public int hashCode() {
     return rates != null ? rates.hashCode() : 0;
   }

   @Override
   public String toString() {
     return "["+this.getClass().getName()+" : " + rates.size() + " rates.]";
   }

   @Override
   public Set<String> listAvailableCurrencies() {
     Set<String> currencies = new HashSet<>();
     for(Map.Entry<String, Map<String, Double>> entry : rates.entrySet()) {
       currencies.add(entry.getKey());
       for(String to : entry.getValue().keySet()) {
         currencies.add(to);
       }
     }
     return currencies;
   }

   @Override
   public boolean reload() throws SolrException {
     Map<String, Map<String, Double>> tmpRates = new HashMap<>();
     log.debug("Reloading exchange rates from file {}", currencyConfigFile);

     try {
       Document doc = SafeXMLParsing.parseConfigXML(log, loader, currencyConfigFile);
       XPathFactory xpathFactory = XPathFactory.newInstance();
       XPath xpath = xpathFactory.newXPath();

       // Parse exchange rates.
       NodeList nodes = (NodeList) xpath.evaluate("/currencyConfig/rates/rate", doc, XPathConstants.NODESET);

       for (int i = 0; i < nodes.getLength(); i++) {
         Node rateNode = nodes.item(i);
         NamedNodeMap attributes = rateNode.getAttributes();
         Node from = attributes.getNamedItem("from");
         Node to = attributes.getNamedItem("to");
         Node rate = attributes.getNamedItem("rate");

         if (from == null || to == null || rate == null) {
           throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Exchange rate missing attributes (required: from, to, rate) " + rateNode);
         }

         String fromCurrency = from.getNodeValue();
         String toCurrency = to.getNodeValue();
         Double exchangeRate;

         if (null == CurrencyFieldType.getCurrency(fromCurrency)) {
           throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Specified 'from' currency not supported in this JVM: " + fromCurrency);
         }
         if (null == CurrencyFieldType.getCurrency(toCurrency)) {
           throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Specified 'to' currency not supported in this JVM: " + toCurrency);
         }

         try {
           exchangeRate = Double.parseDouble(rate.getNodeValue());
         } catch (NumberFormatException e) {
           throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Could not parse exchange rate: " + rateNode, e);
         }

         addRate(tmpRates, fromCurrency, toCurrency, exchangeRate);
       }
     } catch (SAXException | IOException | XPathExpressionException e) {
       throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Error while parsing currency configuration file "+currencyConfigFile, e);
     }
     // Atomically swap in the new rates map, if it loaded successfully
     this.rates = tmpRates;
     return true;
   }

   @Override
   public void init(Map<String,String> params) throws SolrException {
     this.currencyConfigFile = params.get(PARAM_CURRENCY_CONFIG);
     if(currencyConfigFile == null) {
       throw new SolrException(SolrException.ErrorCode.NOT_FOUND, "Missing required configuration "+PARAM_CURRENCY_CONFIG);
     }

     // Removing config params custom to us
     params.remove(PARAM_CURRENCY_CONFIG);
   }

   @Override
   public void inform(ResourceLoader loader) throws SolrException {
     if(loader == null) {
       throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Needs ResourceLoader in order to load config file");
     }
     this.loader = loader;
     reload();
   }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.apache.solr.schema;

	import java.io.IOException;
	import java.lang.invoke.MethodHandles;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Map;
	import java.util.Set;

	import javax.xml.xpath.XPath;
	import javax.xml.xpath.XPathConstants;
	import javax.xml.xpath.XPathExpressionException;
	import javax.xml.xpath.XPathFactory;

	import org.apache.lucene.analysis.util.ResourceLoader;
	import org.apache.solr.common.SolrException;
	import org.apache.solr.util.SafeXMLParsing;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;
	import org.w3c.dom.Document;
	import org.w3c.dom.NamedNodeMap;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;
	import org.xml.sax.SAXException;

	/**
	* Configuration for currency. Provides currency exchange rates.
	*/
	public class FileExchangeRateProvider implements ExchangeRateProvider {
	private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

	protected static final String PARAM_CURRENCY_CONFIG = "currencyConfig";

	// Exchange rate map, maps Currency Code -> Currency Code -> Rate
	private Map<String, Map<String, Double>> rates = new HashMap<>();

	private String currencyConfigFile;
	private ResourceLoader loader;

	/**
	* Returns the currently known exchange rate between two currencies. If a direct rate has been loaded,
	* it is used. Otherwise, if a rate is known to convert the target currency to the source, the inverse
	* exchange rate is computed.
	*
	* @param sourceCurrencyCode The source currency being converted from.
	* @param targetCurrencyCode The target currency being converted to.
	* @return The exchange rate.
	* @throws SolrException if the requested currency pair cannot be found
	*/
	@Override
	public double getExchangeRate(String sourceCurrencyCode, String targetCurrencyCode) {
	if (sourceCurrencyCode == null \|\| targetCurrencyCode == null) {
	throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Cannot get exchange rate; currency was null.");
	}

	if (sourceCurrencyCode.equals(targetCurrencyCode)) {
	return 1.0;
	}

	Double directRate = lookupRate(sourceCurrencyCode, targetCurrencyCode);

	if (directRate != null) {
	return directRate;
	}

	Double symmetricRate = lookupRate(targetCurrencyCode, sourceCurrencyCode);

	if (symmetricRate != null) {
	return 1.0 / symmetricRate;
	}

	throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "No available conversion rate between " + sourceCurrencyCode + " to " + targetCurrencyCode);
	}

	/**
	* Looks up the current known rate, if any, between the source and target currencies.
	*
	* @param sourceCurrencyCode The source currency being converted from.
	* @param targetCurrencyCode The target currency being converted to.
	* @return The exchange rate, or null if no rate has been registered.
	*/
	private Double lookupRate(String sourceCurrencyCode, String targetCurrencyCode) {
	Map<String, Double> rhs = rates.get(sourceCurrencyCode);

	if (rhs != null) {
	return rhs.get(targetCurrencyCode);
	}

	return null;
	}

	/**
	* Registers the specified exchange rate.
	*
	* @param ratesMap The map to add rate to
	* @param sourceCurrencyCode The source currency.
	* @param targetCurrencyCode The target currency.
	* @param rate The known exchange rate.
	*/
	private void addRate(Map<String, Map<String, Double>> ratesMap, String sourceCurrencyCode, String targetCurrencyCode, double rate) {
	Map<String, Double> rhs = ratesMap.get(sourceCurrencyCode);

	if (rhs == null) {
	rhs = new HashMap<>();
	ratesMap.put(sourceCurrencyCode, rhs);
	}

	rhs.put(targetCurrencyCode, rate);
	}

	@Override
	public boolean equals(Object o) {
	if (this == o) return true;
	if (o == null \|\| getClass() != o.getClass()) return false;

	FileExchangeRateProvider that = (FileExchangeRateProvider) o;

	return !(rates != null ? !rates.equals(that.rates) : that.rates != null);
	}

	@Override
	public int hashCode() {
	return rates != null ? rates.hashCode() : 0;
	}

	@Override
	public String toString() {
	return "["+this.getClass().getName()+" : " + rates.size() + " rates.]";
	}

	@Override
	public Set<String> listAvailableCurrencies() {
	Set<String> currencies = new HashSet<>();
	for(Map.Entry<String, Map<String, Double>> entry : rates.entrySet()) {
	currencies.add(entry.getKey());
	for(String to : entry.getValue().keySet()) {
	currencies.add(to);
	}
	}
	return currencies;
	}

	@Override
	public boolean reload() throws SolrException {
	Map<String, Map<String, Double>> tmpRates = new HashMap<>();
	log.debug("Reloading exchange rates from file {}", currencyConfigFile);

	try {
	Document doc = SafeXMLParsing.parseConfigXML(log, loader, currencyConfigFile);
	XPathFactory xpathFactory = XPathFactory.newInstance();
	XPath xpath = xpathFactory.newXPath();

	// Parse exchange rates.
	NodeList nodes = (NodeList) xpath.evaluate("/currencyConfig/rates/rate", doc, XPathConstants.NODESET);

	for (int i = 0; i < nodes.getLength(); i++) {
	Node rateNode = nodes.item(i);
	NamedNodeMap attributes = rateNode.getAttributes();
	Node from = attributes.getNamedItem("from");
	Node to = attributes.getNamedItem("to");
	Node rate = attributes.getNamedItem("rate");

	if (from == null \|\| to == null \|\| rate == null) {
	throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Exchange rate missing attributes (required: from, to, rate) " + rateNode);
	}

	String fromCurrency = from.getNodeValue();
	String toCurrency = to.getNodeValue();
	Double exchangeRate;

	if (null == CurrencyFieldType.getCurrency(fromCurrency)) {
	throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Specified 'from' currency not supported in this JVM: " + fromCurrency);
	}
	if (null == CurrencyFieldType.getCurrency(toCurrency)) {
	throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Specified 'to' currency not supported in this JVM: " + toCurrency);
	}

	try {
	exchangeRate = Double.parseDouble(rate.getNodeValue());
	} catch (NumberFormatException e) {
	throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Could not parse exchange rate: " + rateNode, e);
	}

	addRate(tmpRates, fromCurrency, toCurrency, exchangeRate);
	}
	} catch (SAXException \| IOException \| XPathExpressionException e) {
	throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Error while parsing currency configuration file "+currencyConfigFile, e);
	}
	// Atomically swap in the new rates map, if it loaded successfully
	this.rates = tmpRates;
	return true;
	}

	@Override
	public void init(Map<String,String> params) throws SolrException {
	this.currencyConfigFile = params.get(PARAM_CURRENCY_CONFIG);
	if(currencyConfigFile == null) {
	throw new SolrException(SolrException.ErrorCode.NOT_FOUND, "Missing required configuration "+PARAM_CURRENCY_CONFIG);
	}

	// Removing config params custom to us
	params.remove(PARAM_CURRENCY_CONFIG);
	}

	@Override
	public void inform(ResourceLoader loader) throws SolrException {
	if(loader == null) {
	throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Needs ResourceLoader in order to load config file");
	}
	this.loader = loader;
	reload();
	}
	}