Java Community | Help. Code. Learn.•2mo ago

What is wrong with my code?

Hello! I am trying to code along but am not getting the same result. I have been inspecting my code so much I feel a bit blind, so could I perhaps get a second pair of eyes, with maybe a bit more knowledge? I am learning Spring, working with Spring Boot & Databases. It is not much code, three classes so if it's not minded I will just share it here.

5 Replies

JavaBot•2mo ago

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De1oraOP•2mo ago

package me.FolderAPI.FolderAPI.Folder;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import lombok.AllArgsConstructor;
import lombok.Data;

import java.util.UUID;

@Entity
@Data
@AllArgsConstructor
public class Folder { // Klass som representerar en tabell, en model

    @Id // För att informera hibernate om att detta ska vara just id:t
    private UUID id; // Eftersom det är databaser, vill vi ha en primary key

    private String title;
}

package me.FolderAPI.FolderAPI.Folder;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import lombok.AllArgsConstructor;
import lombok.Data;

import java.util.UUID;

@Entity
@Data
@AllArgsConstructor
public class Folder { // Klass som representerar en tabell, en model

    @Id // För att informera hibernate om att detta ska vara just id:t
    private UUID id; // Eftersom det är databaser, vill vi ha en primary key

    private String title;
}

package me.FolderAPI.FolderAPI.Folder;

import lombok.RequiredArgsConstructor;
import lombok.ToString;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.net.URI;
import java.util.UUID;

@RestController
@RequestMapping("/folder")
@RequiredArgsConstructor
public class FolderController {

    private final FolderRepository folderRepository;

    @PostMapping
    public ResponseEntity<?> createFolder(@RequestBody CreateFolderDto dto) {
        if (dto.title == null || dto.title.isBlank()) {
            return ResponseEntity.badRequest().body("Title may not be null or empty");
        }

        Folder folder = new Folder(UUID.randomUUID(), dto.title);
        folderRepository.save(folder);

        return ResponseEntity
                .created(URI.create("/folder"))
                .body(folder);
    }

    @GetMapping
    public ResponseEntity<?> getFolders() {
        return  ResponseEntity.ok(folderRepository.findAll()); // Select star, hämtar allt
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<?> deleteFolder(@PathVariable UUID id) {
        if (folderRepository.findById(id).isEmpty()) {
            return ResponseEntity.notFound().build();
        }

        folderRepository.deleteById(id);
        return ResponseEntity.ok("Deleted folder.");
    }

    @ToString
    public static class CreateFolderDto {
        public String title;
    }
}

package me.FolderAPI.FolderAPI.Folder;

import lombok.RequiredArgsConstructor;
import lombok.ToString;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.net.URI;
import java.util.UUID;

@RestController
@RequestMapping("/folder")
@RequiredArgsConstructor
public class FolderController {

    private final FolderRepository folderRepository;

    @PostMapping
    public ResponseEntity<?> createFolder(@RequestBody CreateFolderDto dto) {
        if (dto.title == null || dto.title.isBlank()) {
            return ResponseEntity.badRequest().body("Title may not be null or empty");
        }

        Folder folder = new Folder(UUID.randomUUID(), dto.title);
        folderRepository.save(folder);

        return ResponseEntity
                .created(URI.create("/folder"))
                .body(folder);
    }

    @GetMapping
    public ResponseEntity<?> getFolders() {
        return  ResponseEntity.ok(folderRepository.findAll()); // Select star, hämtar allt
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<?> deleteFolder(@PathVariable UUID id) {
        if (folderRepository.findById(id).isEmpty()) {
            return ResponseEntity.notFound().build();
        }

        folderRepository.deleteById(id);
        return ResponseEntity.ok("Deleted folder.");
    }

    @ToString
    public static class CreateFolderDto {
        public String title;
    }
}

package me.FolderAPI.FolderAPI.Folder;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import java.util.UUID;

@Repository
public interface    FolderRepository extends JpaRepository<Folder, UUID> { // Tar in två generiska typer, modelltypen och datatypen.
}

package me.FolderAPI.FolderAPI.Folder;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import java.util.UUID;

@Repository
public interface    FolderRepository extends JpaRepository<Folder, UUID> { // Tar in två generiska typer, modelltypen och datatypen.
}

Ignore the comments. The errors I am getting are in FolderController: Variable 'folderRepository' might not have been initialized :15 'Folder()' cannot be applied to '(java.util.UUID, java.lang.String)' :23 FolderController

package me.FolderAPI.FolderAPI.Folder;

import lombok.RequiredArgsConstructor;
import lombok.ToString;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.net.URI;
import java.util.UUID;

@RestController
@RequestMapping("/folder")
@RequiredArgsConstructor
public class FolderController {

    private final FolderRepository folderRepository;

    @PostMapping
    public ResponseEntity<?> createFolder(@RequestBody CreateFolderDto dto) {
        if (dto.title == null || dto.title.isBlank()) {
            return ResponseEntity.badRequest().body("Title may not be null or empty");
        }

        Folder folder = new Folder(UUID.randomUUID(), dto.title);
        folderRepository.save(folder);

        return ResponseEntity
                .created(URI.create("/folder"))
                .body(folder);
    }

    @GetMapping
    public ResponseEntity<?> getFolders() {
        return  ResponseEntity.ok(folderRepository.findAll()); // Select star, hämtar allt
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<?> deleteFolder(@PathVariable UUID id) {
        if (folderRepository.findById(id).isEmpty()) {
            return ResponseEntity.notFound().build();
        }

        folderRepository.deleteById(id);
        return ResponseEntity.ok("Deleted folder.");
    }

    @ToString
    public static class CreateFolderDto {
        public String title;
    }
}

package me.FolderAPI.FolderAPI.Folder;

import lombok.RequiredArgsConstructor;
import lombok.ToString;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.net.URI;
import java.util.UUID;

@RestController
@RequestMapping("/folder")
@RequiredArgsConstructor
public class FolderController {

    private final FolderRepository folderRepository;

    @PostMapping
    public ResponseEntity<?> createFolder(@RequestBody CreateFolderDto dto) {
        if (dto.title == null || dto.title.isBlank()) {
            return ResponseEntity.badRequest().body("Title may not be null or empty");
        }

        Folder folder = new Folder(UUID.randomUUID(), dto.title);
        folderRepository.save(folder);

        return ResponseEntity
                .created(URI.create("/folder"))
                .body(folder);
    }

    @GetMapping
    public ResponseEntity<?> getFolders() {
        return  ResponseEntity.ok(folderRepository.findAll()); // Select star, hämtar allt
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<?> deleteFolder(@PathVariable UUID id) {
        if (folderRepository.findById(id).isEmpty()) {
            return ResponseEntity.notFound().build();
        }

        folderRepository.deleteById(id);
        return ResponseEntity.ok("Deleted folder.");
    }

    @ToString
    public static class CreateFolderDto {
        public String title;
    }
}

Update: I added @NoArgsConstructor to my Folder class.

dan1st•2mo ago

Did that fix it? Otherwise: Are you using JDK 23?

red•2mo ago

Did it work?

JavaBot•2mo ago

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