Database entry problem. Only null value is written

I’m trying to work with REST api and after creating JSON post call, null value is written to the database instead of the value that was written in JSON.

I am working with PostgreSQL database.

After I send JSON using Postman or Swagger I get Server Response Code: 200. But the database writes the color as null.

EXAMPLE:

JSON:

{
  "color": "string"
}

Server response:

{
  "id": 2,
  "color": null
}

 connection: keep-alive 
 content-type: application/json 
 date: Thu06 Oct 2022 13:27:09 GMT 
 keep-alive: timeout=60 
 transfer-encoding: chunked 

I added here also application.properties file if I accidentally made some mistake already directly in it.

Project structure:

• controller
• dto
• model
• repository
• service

application.properties

spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://localhost/democalendareventapp
spring.datasource.username=postgres
spring.datasource.password=postgres
spring.jpa.generate-dll=true
spring.datasource.hikari.maximumPoolSize=2

spring.jpa.database-platform=org.hibernate.dialect.PostgreSQL10Dialect
#spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true

spring.mvc.pathmatch.matching-strategy=ant_path_matcher

model: EventCategoryColor

package com.radocode.DemoCalendarEventApp.model;

import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;

@Entity
@NoArgsConstructor
@Data
@Table(name = "EventCategoryColor")
public class EventCategoryColor {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String color;

    public EventCategoryColor(String color) {
        this.color = color;
    }
}

repository: EventCategoryColorRepository

package com.radocode.DemoCalendarEventApp.repository;

import com.radocode.DemoCalendarEventApp.model.EventCategoryColor;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface EventCategoryColorRepository extends CrudRepository<EventCategoryColor, Long> {
}

service – Interface: EventCategoryColorService

package com.radocode.DemoCalendarEventApp.service;

import com.radocode.DemoCalendarEventApp.dto.requestDto.EventCategoryColorRequestDto;
import com.radocode.DemoCalendarEventApp.model.EventCategoryColor;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public interface EventCategoryColorService {
    public EventCategoryColor addColor(EventCategoryColorRequestDto eventCategoryColorRequestDto);
    public List<EventCategoryColor> getColors();
    public EventCategoryColor getColor(Long id);
    public EventCategoryColor deleteColor(Long id);
    public EventCategoryColor editColor(Long id, EventCategoryColorRequestDto eventCategoryColorRequestDto);
}

service: EventCategoryColorServiceImp

package com.radocode.DemoCalendarEventApp.service;

import com.radocode.DemoCalendarEventApp.dto.requestDto.EventCategoryColorRequestDto;
import com.radocode.DemoCalendarEventApp.model.EventCategoryColor;
import com.radocode.DemoCalendarEventApp.repository.EventCategoryColorRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.transaction.Transactional;
import java.util.ArrayList;
import java.util.List;

@Service
public class EventCategoryColorServiceImpl implements EventCategoryColorService {

    private final EventCategoryColorRepository eventCategoryColorRepository;

    @Autowired
    public EventCategoryColorServiceImpl(EventCategoryColorRepository eventCategoryColorRepository) {
        this.eventCategoryColorRepository = eventCategoryColorRepository;
    }

    @Override
    public EventCategoryColor addColor(EventCategoryColorRequestDto eventCategoryColorRequestDto) {
        EventCategoryColor eventCategoryColor = new EventCategoryColor();
        eventCategoryColor.setColor(eventCategoryColor.getColor());
        return eventCategoryColorRepository.save(eventCategoryColor);
    }

    @Override
    public List<EventCategoryColor> getColors() {
        List<EventCategoryColor> colors = new ArrayList<>();
        eventCategoryColorRepository.findAll().forEach(colors::add);
        return colors;
    }

    @Override
    public EventCategoryColor getColor(Long id) {
        return eventCategoryColorRepository.findById(id).orElseThrow(() ->
                new IllegalArgumentException("Color with Id: " + id + ", could not be found"));
    }

    @Override
    public EventCategoryColor deleteColor(Long id) {
        EventCategoryColor eventCategoryColor = getColor(id);
        eventCategoryColorRepository.delete(eventCategoryColor);
        return eventCategoryColor;
    }

    @Transactional
    @Override
    public EventCategoryColor editColor(Long id, EventCategoryColorRequestDto eventCategoryColorRequestDto) {
        EventCategoryColor colorToEdit = getColor(id);
        colorToEdit.setColor(eventCategoryColorRequestDto.getColor());
        return colorToEdit;
    }
}

dto: EventCategoryColorRequestDto

package com.radocode.DemoCalendarEventApp.dto.requestDto;

import lombok.Data;

@Data
public class EventCategoryColorRequestDto {
    private String color;
}

controller: EventCategoryColorController

package com.radocode.DemoCalendarEventApp.controller;

import com.radocode.DemoCalendarEventApp.dto.requestDto.EventCategoryColorRequestDto;
import com.radocode.DemoCalendarEventApp.model.EventCategoryColor;
import com.radocode.DemoCalendarEventApp.service.EventCategoryColorService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/event-category-color")
public class EventCatogeryColorController {

    private final EventCategoryColorService eventCategoryColorService;

    @Autowired
    public EventCatogeryColorController(EventCategoryColorService eventCategoryColorService) {
        this.eventCategoryColorService = eventCategoryColorService;
    }

    @PostMapping("/add")
    public ResponseEntity<EventCategoryColor> addColor(
            @RequestBody final EventCategoryColorRequestDto eventCategoryColorRequestDto) {
        EventCategoryColor eventCategoryColor = eventCategoryColorService.addColor(eventCategoryColorRequestDto);
        return new ResponseEntity<>(eventCategoryColor, HttpStatus.OK);
    }

    @GetMapping("/get/{id}")
    public ResponseEntity<EventCategoryColor> getColorById(@PathVariable final Long id) {
        EventCategoryColor eventCategoryColor = eventCategoryColorService.getColor(id);
        return new ResponseEntity<>(eventCategoryColor, HttpStatus.OK);
    }

    @GetMapping("/get-all")
    public ResponseEntity<List<EventCategoryColor>> getColors() {
        List<EventCategoryColor> eventCategoryColors = eventCategoryColorService.getColors();
        return new ResponseEntity<>(eventCategoryColors, HttpStatus.OK);
    }

    @DeleteMapping("/delete/{id}")
    public ResponseEntity<EventCategoryColor> deleteColor(@PathVariable final Long id) {
        EventCategoryColor eventCategoryColor = eventCategoryColorService.deleteColor(id);
        return new ResponseEntity<>(eventCategoryColor, HttpStatus.OK);
    }

    @PutMapping("/edit/{id}")
    public ResponseEntity<EventCategoryColor> editColor(
            @PathVariable final Long id,
            @RequestBody final EventCategoryColorRequestDto eventCategoryColorRequestDto) {
        EventCategoryColor eventCategoryColor = eventCategoryColorService.editColor(id, eventCategoryColorRequestDto);
        return new ResponseEntity<>(eventCategoryColor, HttpStatus.OK);
    }
}

Answer

You set theo color value from the newly created entity to the entity which is not initialized at this time:

@Override
public EventCategoryColor addColor(EventCategoryColorRequestDto eventCategoryColorRequestDto) {
    EventCategoryColor eventCategoryColor = new EventCategoryColor();
    eventCategoryColor.setColor(eventCategoryColor.getColor());
    return eventCategoryColorRepository.save(eventCategoryColor);
}

should be:

@Override
public EventCategoryColor addColor(EventCategoryColorRequestDto eventCategoryColorRequestDto) {
    EventCategoryColor eventCategoryColor = new EventCategoryColor();
    eventCategoryColor.setColor(eventCategoryColorRequestDto.getColor());
    return eventCategoryColorRepository.save(eventCategoryColor);
}