Allow adding a currency extension file for addition non-default currencies

pom.xml

@@ -35,6 +35,11 @@
       <timezone>0</timezone>
     </developer>
   </developers>
+  <contributors>
+    <contributor>
+      <name>Tim Molter</name>
+     </contributor>
+  </contributors>
   <licenses>
     <license>
       <name>Apache 2</name>

src/main/java/org/joda/money/DefaultCurrencyUnitDataProvider.java

@@ -34,38 +34,51 @@ class DefaultCurrencyUnitDataProvider extends CurrencyUnitDataProvider {
     /** Regex format for the csv line. */
     private static final Pattern REGEX_LINE = Pattern.compile("([A-Z]{3}),(-1|[0-9]{1,3}),(-1|0|1|2|3),([A-Z]*)#?.*");
 
+
     /**
      * Registers all the currencies known by this provider.
-     * <p>
-     * This reads the first resource named '/org/joda/money/MoneyData.csv' on the classpath.
      * 
      * @throws Exception if an error occurs
-     */
+     */ 
     @Override
     protected void registerCurrencies() throws Exception {
-        InputStream in = getClass().getResourceAsStream("/org/joda/money/MoneyData.csv");
-        if (in == null) {
-            throw new FileNotFoundException("Data file /org/joda/money/MoneyData.csv not found");
-        }
-        BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
-        String line;
-        while ((line = reader.readLine()) != null) {
-            Matcher matcher = REGEX_LINE.matcher(line);
-            if (matcher.matches()) {
-                List<String> countryCodes = new ArrayList<String>();
-                String codeStr = matcher.group(4);
-                String currencyCode = matcher.group(1);
-                if (codeStr.length() % 2 == 1) {
-                    continue;  // invalid line
-                }
-                for (int i = 0; i < codeStr.length(); i += 2) {
-                    countryCodes.add(codeStr.substring(i, i + 2));
-                }
-                int numericCode = Integer.parseInt(matcher.group(2));
-                int digits = Integer.parseInt(matcher.group(3));
-                registerCurrency(currencyCode, numericCode, digits, countryCodes);
-            }
-        }
+      loadCurrenciesFromFile("/org/joda/money/MoneyData.csv", true);
+      loadCurrenciesFromFile("/org/joda/money/MoneyDataExtension.csv", false); 
+    }
+
+    /**
+     * Loads Currencies from a file
+     *  
+     * @param fileName the file to load
+     * @param isNecessary whether or not the file is necessary
+     * @throws Exception if a necessary file isn't found
+     */
+    private void  loadCurrenciesFromFile(String fileName, boolean isNecessary)  throws Exception {
+      InputStream in = getClass().getResourceAsStream(fileName);
+      if (in == null && isNecessary) {
+          throw new FileNotFoundException("Data file " + fileName + " not found");
+      }else if (in == null && !isNecessary) {
+       return; // no extension file found, no problem. just return
+      }
+      BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
+      String line;
+      while ((line = reader.readLine()) != null) {
+          Matcher matcher = REGEX_LINE.matcher(line);
+          if (matcher.matches()) {
+              List<String> countryCodes = new ArrayList<String>();
+              String codeStr = matcher.group(4);
+              String currencyCode = matcher.group(1);
+              if (codeStr.length() % 2 == 1) {
+                  continue;  // invalid line
+              }
+              for (int i = 0; i < codeStr.length(); i += 2) {
+                  countryCodes.add(codeStr.substring(i, i + 2));
+              }
+              int numericCode = Integer.parseInt(matcher.group(2));
+              int digits = Integer.parseInt(matcher.group(3));
+              registerCurrency(currencyCode, numericCode, digits, countryCodes);
+          }
+      }
     }
 
 }

src/test/java/org/joda/money/MoneyDataExtension.csv

@@ -0,0 +1,2 @@
+#Code,Numeric,DecPlaces,CountryCodes
+BTC,-1,-1,

src/test/java/org/joda/money/TestCurrencyUnitExtension.java

@@ -0,0 +1,77 @@
+/*
+ *  Copyright 2009-2013 Stephen Colebourne
+ *
+ *  Licensed 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.joda.money;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Currency;
+import java.util.List;
+import java.util.Locale;
+
+import org.testng.annotations.Test;
+
+/**
+ * Test CurrencyUnit.
+ */
+@Test
+public class TestCurrencyUnitExtension {
+
+
+  public void test_CurrencyFromMoneyData() {
+    List<CurrencyUnit> curList = CurrencyUnit.registeredCurrencies();
+    boolean found = false;
+    for (CurrencyUnit currencyUnit : curList) {
+        if (currencyUnit.getCode().equals("GBP")) {
+            found = true;
+            break;
+        }
+    }
+    assertEquals(found, true);
+   }
+
+    public void test_CurrencyFromMoneyDataExtension() {
+        List<CurrencyUnit> curList = CurrencyUnit.registeredCurrencies();
+        boolean found = false;
+        for (CurrencyUnit currencyUnit : curList) {
+            if (currencyUnit.getCode().equals("BTC")) {
+                found = true;
+                break;
+            }
+        }
+        assertEquals(found, true);
+    }
+
+    public void test_CurrencyMissing() {
+      List<CurrencyUnit> curList = CurrencyUnit.registeredCurrencies();
+      boolean found = false;
+      for (CurrencyUnit currencyUnit : curList) {
+          if (currencyUnit.getCode().equals("NMC")) {
+              found = true;
+              break;
+          }
+      }
+      assertEquals(found, false);
+  }
+
+}