GEOMESA-3527 Fix empty string to list GeoTools converter (#3434)

* Tweak make-release-docs script to use latest tag as default

Author: elahrvivaz

build/scripts/make-release-docs.sh

@@ -38,7 +38,7 @@ if ! [[ $(which virtualenv) ]]; then
   exit 1
 fi
 
-TAG="$(git tag | grep '^geomesa-' | sort -r | head -n 1)"
+TAG="$(git tag --list 'geomesa-*' --sort=-creatordate | head -n 1)"
 RELEASE="${TAG#geomesa-}"
 read -r -p "Enter the release version (default $RELEASE): " REL
 if [[ -n "$REL" ]]; then

geomesa-utils-parent/geomesa-utils/src/main/scala/org/locationtech/geomesa/utils/geotools/converters/StringCollectionConverterFactory.scala

@@ -62,7 +62,7 @@ object StringCollectionConverterFactory {
     *
     * @param listType type of list elements
     */
-  class StringToListConverter(listType: Class[_]) extends Converter {
+  private class StringToListConverter(listType: Class[_]) extends Converter {
 
     override def convert[T](source: scala.Any, target: Class[T]): T = {
       val string = source.toString.trim
@@ -71,7 +71,7 @@ object StringCollectionConverterFactory {
       // geomesa looks like: value1,value2
       val isToString = string.startsWith("[") && string.endsWith("]")
       val stripped = if (isToString) string.substring(1, string.length - 1) else string
-      if (string.isEmpty) {
+      if (stripped.isEmpty) {
         new java.util.ArrayList[Any](0).asInstanceOf[T]
       } else {
         val result = new java.util.ArrayList[Any]
@@ -101,7 +101,7 @@ object StringCollectionConverterFactory {
     * @param keyType map key type
     * @param valueType map value type
     */
-  class StringToMapConverter(keyType: Class[_], valueType: Class[_]) extends Converter {
+  private class StringToMapConverter(keyType: Class[_], valueType: Class[_]) extends Converter {
 
     override def convert[T](source: scala.Any, target: Class[T]): T = {
       val string = source.toString.trim