java - 将 UUID 与 Spring 引导数据一起使用

Question

我在我的应用程序中使用 UUID 作为主键当我通过 id 查找数据时遇到问题给我异常错误。 这是笔记类

  package com.example.demo.model;

    import java.util.Date;
    import java.util.UUID;

    import javax.persistence.CascadeType;
    import javax.persistence.Entity;
    import javax.persistence.FetchType;
    import javax.persistence.GeneratedValue;
    import javax.persistence.GenerationType;
    import javax.persistence.Id;
    import javax.persistence.ManyToOne;

    import org.hibernate.annotations.GenericGenerator;
    import org.springframework.boot.autoconfigure.AutoConfigurationPackage;


    @AutoConfigurationPackage
    @Entity
    public class Note {

      @Id
      @GeneratedValue( strategy = GenerationType.AUTO,generator = "pg-uuid")
      @GenericGenerator(name = "pg-uuid",strategy = "uuid2")
      private UUID id;
      private String title;
      private String text;
      @ManyToOne(fetch = FetchType.LAZY,cascade = CascadeType.MERGE)
      private Notebook notebook;
      private Date lastModifiedOn;


      public UUID getId() {
          return id;
      }
      public void setId(UUID id) {
          this.id = id;
      }
      public String getTitle() {
          return title;
      }
      public void setTitle(String title) {
          this.title = title;
      }
      public String getText() {
          return text;
      }
      public void setText(String text) {
          this.text = text;
      }
      public Notebook getNotebook() {
          return notebook;
      }
      public void setNotebook(Notebook notebook) {
          this.notebook = notebook;
      }
      public Date getLastModifiedOn() {
          return lastModifiedOn;
      }
      public void setLastModifiedOn(Date lastModifiedOn) {
          this.lastModifiedOn = lastModifiedOn;
      }

这是 NoteController

package com.example.demo.controller;

import java.text.ParseException;
import java.util.List;
import java.util.UUID;
import java.util.stream.Collectors;

import javax.persistence.EntityNotFoundException;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.example.demo.MyMapper;
import com.example.demo.Repository.NoteBookRepository;
import com.example.demo.Repository.NoteRepository;
import com.example.demo.model.Note;
import com.example.demo.model.Notebook;
import com.example.demo.view.NoteViewModle;

@RestController
@RequestMapping("/api/note")
@CrossOrigin
public class NoteController {

    @Autowired
    NoteRepository noteRepository;

    @Autowired
    NoteBookRepository notebookRepository;

    @Autowired
    MyMapper maper;

    @GetMapping("/all")
    public List<NoteViewModle> getAllNote(){
        List<Note> list = this.noteRepository.findAll();
        List<NoteViewModle> noteViewModles = (List<NoteViewModle>) list.stream().map(note ->maper.convertToNodeViewModel(note)).collect(Collectors.toList());
        return noteViewModles;
    }

    @GetMapping("/byId/{id}")
    public NoteViewModle getNotreById(@PathVariable("id") UUID id) {
        System.out.println(id);
        Note note = this.noteRepository.findById(id).orElse(null); 

        if(note == null)
        {

            System.out.println("In If");
            throw new EntityNotFoundException();

        }

        NoteViewModle modle = maper.convertToNodeViewModel(note);

        return modle;
    }

    @GetMapping("/byNoteBook/{notebookId}")
    public List<Note> getNotesByNoteBook(@PathVariable("notebookId") String id)
    {
        return this.noteRepository.findAllByNotebook(this.notebookRepository.findById(UUID.fromString(id)).orElse(new Notebook()));
    }

    @PostMapping("/add")
    public Note save(@RequestBody NoteViewModle modle)
    {   
        Note note = maper.convertToNodeEntity(modle);
        return this.noteRepository.save(note);
    }

    @DeleteMapping("/deltebyId/{id}")
    public void deleteNoteById(@PathVariable("id") String id) {
        this.noteRepository.deleteById(UUID.fromString(id));
    }

}

这是映射 json 数据的 MyMapper

   package com.example.demo;

    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.UUID;

    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;

    import com.example.demo.Repository.NoteBookRepository;
    import com.example.demo.model.Note;
    import com.example.demo.model.Notebook;
    import com.example.demo.view.NoteViewModle;
    import com.example.demo.view.NotebookViewModel;
    @Component
    public class MyMapper {
        @Autowired
        NoteBookRepository bookRepository;

        public NoteViewModle convertToNodeViewModel(Note entity) {
            NoteViewModle modle = new NoteViewModle();
            modle.setId(entity.getId().toString());
            modle.setTitle(entity.getTitle());
            modle.setText(entity.getText());
            modle.setNoteBookId(entity.getNotebook().getId().toString());
            modle.setData(entity.getLastModifiedOn().toString());
            return modle;
        }

        public Note  convertToNodeEntity(NoteViewModle viewModle) {
            Note note = new Note();
            note.setTitle(viewModle.getTitle());
            note.setText(viewModle.getText());
            //note.setLastModifiedOn(new SimpleDateFormat("dd/MM/yyyy").parse(viewModle.getData()));
            //Notebook notebook = bookRepository.findById(UUID.fromString(viewModle.getId())).orElse(new Notebook());

            return note;
        }


        public NotebookViewModel convertToNotebookViewModel(Notebook entity)
        {
            NotebookViewModel viewModel = new NotebookViewModel();

            viewModel.setId(entity.getId().toString());
            viewModel.setName(entity.getName());
            viewModel.setNumOfNote(entity.getNotes().size());
            return viewModel;
        }

        public Notebook convertToNotebookEntity(NotebookViewModel model) {
            Notebook notebook = new Notebook();
            notebook.setId(UUID.fromString(model.getId()));
            notebook.setName(model.getName());
            return notebook;
        }

    }

这是存储库类

package com.example.demo.Repository;

import java.util.List;
import java.util.UUID;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import com.example.demo.model.Note;
import com.example.demo.model.Notebook;

@Repository
public interface NoteRepository extends JpaRepository<Note, UUID> {

    List<Note> findAllByNotebook(Notebook notebook);
}

这是错误出现org.springframework.dao.EmptyResultDataAccessException: No class com.example.demo.model.Notebook entity with id 7e83b195-eb81-4752-a6fa-a5206c9eb1c6 存在！

标签： javaspring