ObjectToStringHttpMessageConverter(conversionService: ConversionService)
A constructor accepting a ConversionService to use to convert the (String) message body to/from the target class type. This constructor uses StringHttpMessageConverter#DEFAULT_CHARSET as the default charset.
conversionService - the conversion service
ObjectToStringHttpMessageConverter(conversionService: ConversionService, defaultCharset: Charset)
A constructor accepting a ConversionService as well as a default charset.