Failed to convert value of type 'java.lang.String' to required type 'java.time.LocalDate';

Question

I want to get a date passed as a query parameter to a Spring MVC controller.

I've got this dependency:

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

My URL looks like:

http://localhost:8080/userProducts/2?date=2019-3-29

My controller class looks like:

package trainingapp.userproduct;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.web.bind.annotation.*;
import trainingapp.calculations.NutrientsCalculationFacade;
import trainingapp.historysystemofmeals.HistorySystemService;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.List;

@RestController
public class UserProductController {

    private final NutrientsCalculationFacade userProductCalculationFacade;
    private final UserProductFindOperationService userProductFindOperationService;
    private final HistorySystemService historySystemService;

    @Autowired
    public UserProductController(NutrientsCalculationFacade userProductCalculationFacade, UserProductFindOperationService userProductFindOperationService, HistorySystemService historySystemService) {
        this.userProductCalculationFacade = userProductCalculationFacade;
        this.userProductFindOperationService = userProductFindOperationService;
        this.historySystemService = historySystemService;
    }

    //yyyy-MM-dd
    @GetMapping("/userProducts/{userID}")
    public String getAllEatenSummedNutrientsByGivenIDInParticularDay(@PathVariable int userID,
                                                                     @RequestParam("date")
                                                                     @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate date) {
        return historySystemService.getAllEatenSummedNutrientsByGivenIDInParticularDay(userID, date);
    }
}

I get the following error:

{
    "timestamp": "2019-03-29T15:22:44.640+0000",
    "status": 400,
    "error": "Bad Request",
    "message": "Failed to convert value of type 'java.lang.String' to required type 'java.time.LocalDate'; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [@org.springframework.web.bind.annotation.RequestParam @org.springframework.format.annotation.DateTimeFormat java.time.LocalDate] for value '2019-3-29'; nested exception is java.lang.IllegalArgumentException: Parse attempt failed for value [2019-3-29]",
    "path": "/userProducts/2"
}

What should I change or add? I was trying to resolve this problem with How to use LocalDateTime RequestParam in Spring? I get "Failed to convert String to LocalDateTime", but it didnt work.

Answer 1

2019-3-29 is a bad input and the 400 status code is accurate. See the DateTimeFormat.ISO#DATE documentation:

The most common ISO Date Format yyyy-MM-dd, e.g. "2000-10-31".

So, to match the above format, your input should be 2019-03-29 instead.