Added support for base64Encode

src/main/java/strman/Strman.java

@@ -302,9 +302,21 @@ public abstract class Strman {
      * @return decoded data
      */
     public static String base64Decode(final String value) {
+        validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
         return new String(Base64.getDecoder().decode(value));
     }
 
+    /**
+     * Encodes data with MIME base64.
+     *
+     * @param value The data to encode
+     * @return The encoded String
+     */
+    public static String base64Encode(final String value) {
+        validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
+        return Base64.getEncoder().encodeToString(value.getBytes());
+    }
+
     private static long countSubstr(String value, String subStr, boolean allowOverlapping, long count) {
         int position = value.indexOf(subStr);
         if (position == -1) {

src/test/java/strman/StrmanTest.java

@@ -253,6 +253,15 @@ public class StrmanTest {
         assertThat(base64Decode("YmFy"), equalTo("bar"));
         assertThat(base64Decode("YsOhciE="), equalTo("bár!"));
         assertThat(base64Decode("5ryi"), equalTo("漢"));
+    }
+
+    @Test
+    public void base64Encode_shouldEncodeAString() throws Exception {
+        assertThat(base64Encode("strman"), equalTo("c3RybWFu"));
+        assertThat(base64Encode("foo"), equalTo("Zm9v"));
+        assertThat(base64Encode("bar"), equalTo("YmFy"));
+        assertThat(base64Encode("bár!"), equalTo("YsOhciE="));
+        assertThat(base64Encode("漢"), equalTo("5ryi"));
 
     }
 }