Maxkit: GraphQL with SpringBoot & MySQL

這是使用 SpringBoot 並將資料放在 MySQL 的 GraphQL sample

建立專案

在 Spring Initializer 產生 maven project，在 Dependencies 的部分增加

Lombok
MySQL Driver
Spring Data JPA
Spring Web

取得 project 後，再增加 Graphql dependencies

              <dependency>
            <groupId>com.graphql-java</groupId>
            <artifactId>graphql-spring-boot-starter</artifactId>
            <version>5.0.2</version>
        </dependency>
        <dependency>
            <groupId>com.graphql-java</groupId>
            <artifactId>graphql-java-tools</artifactId>
            <version>5.2.4</version>
        </dependency>

Data Model

因應 MySQL 的 Table，需要先產生 ORM 的 Data Model

Post.java

package com.example.writeup.model;

import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import javax.persistence.*;
import java.util.Date;

@Getter
@Setter
@NoArgsConstructor
@Entity
@Table(name = "USER")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "USER_ID")
    private Integer userId;

    @Column(name = "FIRST_NAME")
    private String firstName;

    @Column(name = "LAST_NAME")
    private String lastName;

    @Column(name = "DOB")
    private Date dob;

    @Column(name = "ADDRESS")
    private String address;

    @Column(name = "POST_ID")
    private Integer postId;

    public User(String firstName, String lastName, Date dob, String address, Integer postId) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.dob = dob;
        this.address = address;
        this.postId = postId;
    }
}

User.java

package com.example.writeup.model;

import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import javax.persistence.*;
import java.util.Date;

@Getter
@Setter
@NoArgsConstructor
@Entity
@Table(name = "USER")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "USER_ID")
    private Integer userId;

    @Column(name = "FIRST_NAME")
    private String firstName;

    @Column(name = "LAST_NAME")
    private String lastName;

    @Column(name = "DOB")
    private Date dob;

    @Column(name = "ADDRESS")
    private String address;

    @Column(name = "POST_ID")
    private Integer postId;

    public User(String firstName, String lastName, Date dob, String address, Integer postId) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.dob = dob;
        this.address = address;
        this.postId = postId;
    }
}

Repository

這是用來跟資料庫建立跟剛剛的 Data Model 的關聯

PostRepository.java

package com.example.writeup.repository;

import com.example.writeup.model.Post;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface PostRepository extends JpaRepository<Post,Integer> {
}

UserRepository.java

package com.example.writeup.repository;

import com.example.writeup.model.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

@Repository
public interface UserRepository extends JpaRepository<User, Integer> {

    @Transactional
    @Modifying
    @Query(value = "UPDATE user SET address = ?1 WHERE user_id = ?2 ", nativeQuery = true)
    int updateUserAddress(String address, Integer user_id);

}

Note: 原文說可以改為繼承 CrudRepository，但 find 會回傳一般的 List，但 JpaRepository 會回傳 iterable list ref: What is difference between CrudRepository and JpaRepository interfaces in Spring Data JPA?

DataLoader

用在 init project 時，會自動產生 MySQL table 及測試資料

DataLoader.java

package com.example.writeup.service;

import com.example.writeup.model.Post;
import com.example.writeup.model.User;
import com.example.writeup.repository.PostRepository;
import com.example.writeup.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.annotation.PostConstruct;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.ThreadLocalRandom;

@Service
public class DataLoader {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private PostRepository postRepository;

    @PostConstruct
    public void loadData(){

        User user1 = new User("Yasas" ,"Sandeepa",DataLoader.getRandomDate(),"Mount Pleasant Estate Galle",1);
        User user2 = new User("Sahan" ,"Rambukkna",DataLoader.getRandomDate(),"Delkanda Nugegoda",2);
        User user3 = new User("Ranuk" ,"Silva",DataLoader.getRandomDate(),"Yalawatta gampaha",3);

        Post post1 = new Post("Graphql with SpringBoot",DataLoader.getRandomDate());
        Post post2 = new Post("Flutter with Firebase",DataLoader.getRandomDate());
        Post post3 = new Post("Nodejs Authentication with JWT",DataLoader.getRandomDate());

        postRepository.save(post1);
        postRepository.save(post2);
        postRepository.save(post3);

        userRepository.save(user1);
        userRepository.save(user2);
        userRepository.save(user3);
    }

    public static Date getRandomDate(){
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.YEAR, 1990);
        calendar.set(Calendar.MONTH, 1);
        calendar.set(Calendar.DATE, 2);
        Date date1 = calendar.getTime();
        calendar.set(Calendar.YEAR, 1996);
        Date date2 = calendar.getTime();
        long startMillis = date1.getTime();
        long endMillis = date2.getTime();
        long randomMillisSinceEpoch = ThreadLocalRandom
                .current()
                .nextLong(startMillis, endMillis);

        return new Date(randomMillisSinceEpoch);
    }
}

application.properties

產生設定檔

server.port=7000

#mysql properties
spring.jpa.generate-ddl=true
spring.datasource.url=jdbc:mysql://localhost/writeup
spring.datasource.username=user
spring.datasource.password=password
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.jpa.hibernate.ddl-auto=create

#graphql properties
graphql.servlet.corsEnabled=true
graphql.servlet.mapping=/graphql
graphql.servlet.enabled=true

GraphQL

一開始的 pom.xml 已增加了相關 dependencies
剛剛的 application.properties 增加 graphql.servlet 的設定
建立 GraphQL schema

schema.graphqls

schema {
    query: Query,
    mutation: Mutation,
}

type Query{
    # Fetch All Users
    getAllUsers:[User]

}

type Mutation {
    # Update the user address
    updateUserAddress(userId:Int,address:String): User
}

type User {
    userId : ID!,
    firstName :String,
    lastName :String,
    dob:String,
    address:String,
    postId : Int,
}

產生 Service

UserService.java

package com.example.writeup.service;

import com.coxautodev.graphql.tools.GraphQLMutationResolver;
import com.coxautodev.graphql.tools.GraphQLQueryResolver;
import com.example.writeup.model.User;
import com.example.writeup.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserService implements GraphQLQueryResolver, GraphQLMutationResolver {

    @Autowired
    private UserRepository userRepository;

    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    public User updateUserAddress(Integer userId, String address) throws Exception {
        try {
            userRepository.updateUserAddress(address, userId);
            User user = userRepository.findById(userId).get();
            return user;
        } catch (Exception e) {
            throw new Exception(e);
        }
    }
}

WriteupApplication

package com.example.writeup;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class WriteupApplication {

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

}