In fastjason data type, there is a problem of $ref: "$.list[0]" when parsing jsonobject

One 、 Preface

It is often used in actual development fastjson Related data structure in . Today, it is re parsed by iterator loop 、 assemble fastJson after , Console output traversal found some more in the array “$ref” This is a mess of data

Two 、 reason

JSONObject Reference detection is on by default , Repeated references to objects are $ref Instead of . Because of my addJson Inside keyt It is the same and repeated , Therefore, after re traversing the assembly, there will be alternative data in it .

3、 ... and 、 Solution

entity.setChangeAft(JSONObject.toJSONString(changeAfter, SerializerFeature.DisableCircularReferenceDetect));

When adding to an entity class , hold JSON Turn off reference detection