Added method for parsing Doubles

src/main/java/com/rometools/utils/Doubles.java

@@ -0,0 +1,25 @@
+package com.rometools.utils;
+
+public class Doubles {
+
+    private Doubles() {
+    }
+
+    /**
+     * Converts a String into an Double.
+     *
+     * @param s The String to convert, may be null
+     * @return The parsed Double or null when parsing is not possible
+     */
+    public static Double parse(final String s) {
+        Double parsed = null;
+        try {
+            if (s != null) {
+                parsed = Double.parseDouble(s);
+            }
+        } catch (final NumberFormatException e) {
+        }
+        return parsed;
+    }
+
+}

src/test/java/com/rometools/utils/DoublesTest.java

@@ -0,0 +1,26 @@
+package com.rometools.utils;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+import org.junit.Test;
+
+public class DoublesTest {
+
+    @Test
+    public void testParse() {
+
+        final String nullString = null;
+        final String emptyString = null;
+        final String integerString = "1";
+        final String decimalString = "1.0";
+
+        assertThat(Doubles.parse(nullString), is(nullValue()));
+        assertThat(Doubles.parse(emptyString), is(nullValue()));
+        assertThat(Doubles.parse(integerString), is(1.0));
+        assertThat(Doubles.parse(decimalString), is(1.0));
+
+    }
+
+}