Spring Boot and Google Cloud Cloud DataStore

Question

Requirement: Spring boot Application with datastore(emulator in local) as DB

I am looking for a sample spring boot application which uses datastore emulator to execute basic GET and POST methods.

I am not able to find such an example till now... can someone guide me on this..

Answer 1

You can check this example from google

For the emulator part you can refer to this doc

Book class

package com.example.demo;
import org.springframework.cloud.gcp.data.datastore.core.mapping.Entity;
import org.springframework.data.annotation.Id;

@Entity(name = "books")
public class Book {

    @Id
    Long id;

    String title;

    String author;

    int year;

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

    public long getId() {
            return this.id;
    }

    @Override
    public String toString() {
            return "Book{" +
                            "id=" + this.id +
                            ", title='" + this.title + '\'' +
                            ", author='" + this.author + '\'' +
                            ", year=" + this.year +
                            '}';
    }
}

BookRepository interface

package com.example.demo;

import java.util.List;

import org.springframework.cloud.gcp.data.datastore.repository.DatastoreRepository;


public interface BookRepository extends DatastoreRepository<Book, Long> {

  List<Book> findByAuthor(String author);

  List<Book> findByYearGreaterThan(int year);

  List<Book> findByAuthorAndYear(String author, int year);

}

Demo app

package com.example.demo;

import java.util.List;

import com.google.common.collect.Lists;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.shell.standard.ShellComponent;
import org.springframework.shell.standard.ShellMethod;

@ShellComponent
@SpringBootApplication
public class DemoApplication {
  @Autowired
  BookRepository bookRepository;

  public static void main(String[] args) {
     SpringApplication.run(DemoApplication.class, args);
  }

  @ShellMethod("Saves a book to Cloud Datastore: save-book <title> <author> <year>")
  public String saveBook(String title, String author, int year) {
     Book savedBook = this.bookRepository.save(new Book(title, author, year));
     return savedBook.toString();
  }

  @ShellMethod("Loads all books")
  public String findAllBooks() {
     Iterable<Book> books = this.bookRepository.findAll();
     return Lists.newArrayList(books).toString();
  }

  @ShellMethod("Loads books by author: find-by-author <author>")
  public String findByAuthor(String author) {
     List<Book> books = this.bookRepository.findByAuthor(author);
     return books.toString();
  }

  @ShellMethod("Loads books published after a given year: find-by-year-after <year>")
  public String findByYearAfter(int year) {
     List<Book> books = this.bookRepository.findByYearGreaterThan(year);
     return books.toString();
  }

  @ShellMethod("Loads books by author and year: find-by-author-year <author> <year>")
  public String findByAuthorYear(String author, int year) {
     List<Book> books = this.bookRepository.findByAuthorAndYear(author, year);
     return books.toString();
  }

  @ShellMethod("Removes all books")
  public void removeAllBooks() {
     this.bookRepository.deleteAll();
  }
}