[JAVA] Try using DI container with Laravel and Spring Boot

Introduction

This is an article from Your Meister Advent Calendar 2019 Day 13. (This is an article that outputs what you have learned since you became a member of society.)

Background of this time

After becoming a member of society, I learned the concept of DI (Dependency Injection). When developing web services, there were many occasions when I used a framework, but I remember that the concept of DI did not appear in the Cake PHP that I mainly used. (I'm sorry if I have a wrong memory.)

DI uses a pre-registered instance by using what is called a DI container or service container (called a DI container in Spring Boot and a service container in Laravel) instead of creating an instance with new and using it. To do.

This time, I would like to write an article on the theme of using DI containers in Spring Boot, which I use for business, and using service containers in Laravel, which I am learning by myself recently.

For Spring Boot

Use constructor injection

I will write using the code I wrote in the article on the 7th day of Your Meister Advent Calendar 2019. Try to switch DB dynamically with Spring Boot https://github.com/Masaki-Ogawa/datasourceDemo

1. PersonRepository.java

PersonRepository.java

package com.example.dataSourceDemo.domain.repositories;

import com.example.dataSourceDemo.domain.models.Person;
import org.springframework.data.jpa.repository.JpaRepository;

@Repository
public interface PersonRepository extends JpaRepository<Person, Integer> {

}

Repository class that inherits JpaRepository

2. PersonServiceImpl.java

PersonServiceImpl.java

package com.example.dataSourceDemo.domain.services;

import com.example.dataSourceDemo.annotations.DataSource;
import com.example.dataSourceDemo.annotations.DataSource.DataSourceType;
import com.example.dataSourceDemo.domain.models.Person;
import com.example.dataSourceDemo.domain.repositories.PersonRepository;
import java.util.List;
import org.springframework.stereotype.Service;

@Service
public class PersonServiceImpl implements PersonService {

  private final PersonRepository personRepository;

  public PersonServiceImpl(
      PersonRepository personRepository) {
    this.personRepository = personRepository;
  }

  /**
   *Method to get Person table record from stg DB
   * @record in the return Person table
   */
  @Override
  public List<Person> findAllPersonInStg() {
    return personRepository.findAll();
  }

  /**
   *Method to get Person table record from stg DB
   * @record in the return Person table
   */
  @DataSource(value = DataSourceType.PROD)
  @Override
  public List<Person> findAllPersonInProd() {
    return personRepository.findAll();
  }
}

I am doing DI here.

In particular,

private final PersonRepository personRepository;

  public PersonServiceImpl(
      PersonRepository personRepository) {
    this.personRepository = personRepository;
  }

DI is performed by constructor injection in the part of. It is registered in the DI container by using the annotations @ Service and @ Repository. To use it, create an instance using constructor injection etc. as described above.

reference Spring Framework Summary-About DI

DI in Laravel

Use a service provider

Create a service provider to register the created service as a service container. This time, I created a service class called DemoService.

AppServiceProvider.php

class AppServiceProvider extends ServiceProvider
{
    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        $this->app->bind('App\Services\DemoService');
    }

    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        //
    }
}

Register the service as described above.

DemoService.php

class DemoService {
    public function show() {
        echo "Show something";
    }
}

The service class is suitable this time, but only implement the method that outputs some characters.

DemoController.php

class MessageController extends Controller
{
    protected $demoService;

    public function __construct(DemoService $demoService)
    {
        $this->demoService = $demoService;
    }

    public function index(Request $request) {

        return $this->demoService->show();
    }
}

In this way, we also use constructor injection to do DI.

At the end

Personally, I feel that Spring Boot, which can be registered in the DI container with annotations such as @ Service and @ Controller, is easier to use. After all, using Java and Spring Boot, there are many situations where the power of annotation is noticed.

Also, as I wrote in the Advent calendar on the 7th day, each framework has good and bad points, and the experience of touching many frameworks is that when I make something in the future, "What kind of thing should I adopt?" If so, is it the best for the product? "

In the future, I would like to continue to touch on both business and non-business.