java.lang.StackOverflowError
at com.alibaba.fastjson.serializer.SerializeWriter.writeStringWithDoubleQuote(SerializeWriter.java:758)
at com.alibaba.fastjson.serializer.SerializeWriter.writeFieldName(SerializeWriter.java:1690)
at com.alibaba.fastjson.serializer.SerializeWriter.writeFieldName(SerializeWriter.java:1672)

Circular error is reported because my JSON plus json.tojsonstring (string, serializerfeature. Disablecircularreferencedetect)

Cycle detection is removed, but the effect of dead cycle will appear