A client that requests data in JSON format, does not always get data in JSON format.

When using listener converters, such as "key-value-with-previous-converter-factory", the server must construct an instance of KeyValueWithPrevious in JSON format, but the resulting output looks like this:

{ _type : 'org.infinispan.commons.util.KeyValueWithPrevious', key : '{"k":"jlisten-modify"}', value : '{"v":"jv1"}', prev : '{"v":"jv0"}' }

The problem here is that key/value/prev are wrapped in '' which makes them String. This wrapping should not be done.