#23 fix number parsing bug

src/main/java/com/crazzyghost/alphavantage/parser/NoneableDoubleAdapter.java

@@ -13,7 +13,7 @@ public Double toJson(@NoneableDouble Double l) {
     @FromJson
     @NoneableDouble
     public Double fromJson(String s) {
-        return s.equalsIgnoreCase("none") ? null: Double.valueOf(s);
+        return Parser.getNumberFromString(s, Double::parseDouble);
     }
 
 }

src/main/java/com/crazzyghost/alphavantage/parser/NoneableLongAdapter.java

@@ -13,7 +13,7 @@ public Long toJson(@NoneableLong Long l) {
     @FromJson
     @NoneableLong
     public Long fromJson(String s) {
-        return s.equalsIgnoreCase("none") ? null: Long.valueOf(s);
+        return Parser.getNumberFromString(s, Long::parseLong);
     }
 
 }

src/main/java/com/crazzyghost/alphavantage/parser/Parser.java

@@ -8,6 +8,7 @@
 import java.lang.reflect.Type;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 
 /**
  * @author crazzyghost
@@ -62,4 +63,14 @@ public static String toJSON(Map<String, Object> data) throws IOException {
         Type type = Types.newParameterizedType(Map.class, String.class, Object.class);
         return moshi.adapter(type).toJson(data);
     }
+
+    public static <N extends Number> N getNumberFromString(String s, Function<String, N> parser) {
+        N result = null;
+        try {
+            result = parser.apply(s);
+        } catch (NumberFormatException ex) {
+        }
+
+        return result;
+    }
 }

src/test/java/parser/ParserUtilTest.java

@@ -0,0 +1,34 @@
+package parser;
+
+import com.crazzyghost.alphavantage.parser.Parser;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+public class ParserUtilTest {
+
+    @Test
+    public void testGetLongFromString() {
+        long actualNum = Parser.getNumberFromString("1", Long::parseLong);
+        assertEquals(1L, actualNum);
+    }
+
+    @Test
+    public void testGetLongFromNotNumberString() {
+        Long actualNum = Parser.getNumberFromString("-", Long::parseLong);
+        assertNull(actualNum);
+    }
+
+    @Test
+    public void testGetDoubleFromString() {
+        double actualNum = Parser.getNumberFromString("-1.2312342342", Double::parseDouble);
+        assertEquals(-1.2312342342, actualNum, 0.0);
+    }
+
+    @Test
+    public void testGetDoubleFromNotNumberString() {
+        Double actualNum = Parser.getNumberFromString("-", Double::parseDouble);
+        assertNull(actualNum);
+    }
+}