The controller of springboot returns an object. How can the front end receive json data?

    @RequestMapping(value="getUserById")
    @ResponseBody
    public User getUserById(int userId){
        System.out.println("userId="+userId);
        return businessService.getUserById(userId);
    }

result of browser call:

Tue Oct 30 13:46:21 CST 2018
There was an unexpected error (type=Internal Server Error, status=500).
No converter found for return value of type: class com.sunlei.springboot.model.User

won"t springboot do the default json conversion? I think all kinds of jackson packages have been imported into maven. What settings are missing?

Json springboot

Sep.28,2021

Previous: Find a Gantt Chart plug-in

Next: In the vue project, after the build is packaged, the index page opens with an error, MIME type ('text/html');

After parsing Springboot with Fastjson, how can it be applied only to requestBody, returned objects or using the original?
how to use Fastjson, to only process the request message and not to process the return message, or to use the original processing method of SpringBoot? the code to add the Fastjson converter is as follows: @Bean public HttpMessageConverters f...

Fastjson springboot spring java

Mar.06,2021
SpringBoot JSON problem
The JSON returned by the query using SpringBoot s default json, database is like this [{ "bg_CycleId": null, "bg_BugId": null, "bg_Status": "Closed", "bg_Responsible": "", ...

Java json springboot

Mar.23,2021

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1eb71c1-262b.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1eb71c1-262b.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?