toJson for an ArrayList inside a DataRow is only handling Strings, need to handle other types

[StephanWald]

dr! = new DataRow()
ar! = new java.util.ArrayList()
ar!.add("TEST")
ar!.add(12.34)
ar!.add("Boolean.FALSE")
dr!.setFieldValue("A_LIST",ar!)
? dr!.toJson(0)