尝试在springboot中使用post方法时出错

Question

I'm learning Spring Boot rn and I'm getting errors on my way when I'm trying to use POST method.

HTTP code is 400.

That's the error:

Here is the code of my rest controller c:

package com.example.carsapi;

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.awt.*;
import java.util.Optional;

@RestController
@RequestMapping("/cars")
public class CarRestController {

    private final CarService carService;

    @Autowired
    public CarRestController(CarService carService) {
        this.carService = carService;
    }

    @GetMapping
    public ResponseEntity<List> getCars(){
        return new ResponseEntity(carService.findAllCars(), HttpStatus.OK);
    }

    @GetMapping(value = "/id/{id}")
    public ResponseEntity<List> getCarById(@PathVariable Integer id){
        Optional<CarDTO> found = carService.findAllCars().stream().filter(car -> car.getCarId() == id).findFirst();
        if(found.isPresent()){
            return new ResponseEntity(found.get(), HttpStatus.OK);
        } else {
            return new ResponseEntity(HttpStatus.NOT_FOUND);
        }
    }

    @GetMapping(value = "/color/{color}")
    public ResponseEntity<List> getCarByColor(@PathVariable String color){
        Optional<CarDTO> found = carService.findAllCars().stream().filter(car -> car.getColor().equals(color)).findFirst();
        if(found.isPresent()){
            return new ResponseEntity(found.get(), HttpStatus.OK);
        } else {
            return new ResponseEntity(HttpStatus.NOT_FOUND);
        }
    }

    @PostMapping(value = "/add")
    public ResponseEntity addCar(@RequestBody CarDTO car){
        carService.findAllCars().add(car);
        return new ResponseEntity(HttpStatus.CREATED);
    }
}

And there is my JSON code which I'm using:

[ 
    {
        "carId": 3,
        "carBrand": "Audi",
        "carModel": "RS6",
        "color": "red"
    }
]

Hope you'll help me I had even tried with @RequestParam , getting all of the values like id , brand , model and color and then adding a new object with these values which I've got from the query but it still didn't work.

Answer 1

The request is an array while CarDTO is a single object. You can make the request with a body like this(notice the absence of [] ):

{
    "carId": 3,
    "carBrand": "Audi",
    "carModel": "RS6",
    "color": "red"
}