Пример приложения Spring Boot CRUD с MongoDB

implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'
implementation 'org.springframework.boot:spring-boot-starter-web'

spring.data.mongodb.host = localhost
spring.data.mongodb.port=27017
spring.data.mongodb.database=library

package com.betterjavacode.mongodbdemo.mongodbapp.models;

import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;



@Document(collection = "books")
public class Book
{
    @Id
    private String id;

    private String title;
    private String author;
    private String isbn;

    public Book()
    {

    }

    public Book(String title, String author, String isbn)
    {
        this.title = title;
        this.author = author;
        this.isbn = isbn;
    }

    public String getId ()
    {
        return id;
    }

    public void setId (String id)
    {
        this.id = id;
    }

    public String getTitle ()
    {
        return title;
    }

    public void setTitle (String title)
    {
        this.title = title;
    }

    public String getAuthor ()
    {
        return author;
    }

    public void setAuthor (String author)
    {
        this.author = author;
    }

    public String getIsbn ()
    {
        return isbn;
    }

    public void setIsbn (String isbn)
    {
        this.isbn = isbn;
    }
}

package com.betterjavacode.mongodbdemo.mongodbapp.repositories;

import com.betterjavacode.mongodbdemo.mongodbapp.models.Book;
import org.springframework.data.mongodb.repository.MongoRepository;

import java.util.List;

public interface BookRepository extends MongoRepository
{
    List findByTitleContaining(String title);
    List findByAuthor(String name);
}

package com.betterjavacode.mongodbdemo.mongodbapp.controller;

import com.betterjavacode.mongodbdemo.mongodbapp.models.Book;
import com.betterjavacode.mongodbdemo.mongodbapp.repositories.BookRepository;
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.ArrayList;
import java.util.List;
import java.util.Optional;

@CrossOrigin("http://localhost:8080")
@RestController
@RequestMapping("/v1/mongodbapp")
public class BookController
{
    @Autowired
    BookRepository bookRepository;

    @GetMapping("/books")
    public ResponseEntity getAllBooks(@RequestParam(required = false) String bookTitle)
    {
        try
        {
            List listOfBooks = new ArrayList<>();
            if(bookTitle == null || bookTitle.isEmpty())
            {
                bookRepository.findAll().forEach(listOfBooks::add);
            }
            else
            {
                bookRepository.findByTitleContaining(bookTitle).forEach(listOfBooks::add);
            }

            if(listOfBooks.isEmpty())
            {
                return new ResponseEntity<>(HttpStatus.NO_CONTENT);
            }

            return new ResponseEntity<>(listOfBooks, HttpStatus.OK);
        }
        catch (Exception e)
        {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

    @GetMapping("/books/{id}")
    public ResponseEntity getBookById(@PathVariable("id") String id)
    {
        try
        {
            Optional bookOptional = bookRepository.findById(id);

            return new ResponseEntity<>(bookOptional.get(), HttpStatus.OK);
        }
        catch (Exception e)
        {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

    @PostMapping("/books")
    public ResponseEntity addABookToLibrary(@RequestBody Book book)
    {
        try
        {
            Book createdBook = bookRepository.save(new Book(book.getTitle(), book.getAuthor(),
                    book.getIsbn()));
            return new ResponseEntity<>(createdBook, HttpStatus.CREATED);
        }
        catch (Exception e)
        {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

    @PutMapping("/books/{id}")
    public ResponseEntity updateABook(@PathVariable("id") String id, @RequestBody Book book)
    {
        Optional bookOptional = bookRepository.findById(id);

        if(bookOptional.isPresent())
        {
            Book updatedBook = bookOptional.get();
            updatedBook.setTitle(book.getTitle());
            updatedBook.setAuthor(book.getAuthor());
            updatedBook.setIsbn(book.getIsbn());
            return new ResponseEntity<>(bookRepository.save(updatedBook), HttpStatus.OK);
        }
        else
        {
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }

    @DeleteMapping("/books/{id}")
    public ResponseEntity deleteABook(@PathVariable("id") String id)
    {
        try
        {
            bookRepository.deleteById(id);
            return new ResponseEntity<>(HttpStatus.NO_CONTENT);
        }
        catch (Exception e)
        {
            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }
}

* @RestController – to mark this as a REST controller.


@CrossOrigin – This annotation allows cross-origin resource sharing (CORS). This will add CORS access control headers in the REST response. These headers are necessary because it allows servers to specify not only who can access the resources, but how they can be accessed.
We have added different methods – addABookToLibrary adds the book to database, getAllBooks retrieves the book from database.