I'm new in Java. Please help me

This is my restful controller

This is the model

The error when I run the code

CodePudding user response：

Your controller return type is String, and it return getGadaianDetails(), but method getGadaianDetails return type is TreeMap.

you can make your controller return type as TreeMap, this may require re-agreement with the front-end on the data structures that interact.

Or, you can modify the implementation of the getGadaianDetails method so that it returns a string