Graphql入门

这是一篇可以让没有任何graphql基础的人基本可以上手写出一套增删改查+模糊分页（偏后端，Springboot+jpa）

一、首先要引入graphql的pom配置文件

<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>

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

application配置：

graphiql:
  enabled: true

二、在idea下载graphql插件，并在resources下创建graphql包以及graphql类型的配置文件

类似这样。
前期准备工作就差不多了

上主菜

三、主要的代码

controller:

// An highlighted block
@Component
@RequestMapping("query")
public class UserQueryResolver implements GraphQLQueryResolver, GraphQLMutationResolver {

    @Autowired
    private UserService userService;

    @Autowired
    private UserRepository userRepository;

    public List<User> findSearchUsers(User user,int page,int size){
        return userService.findSearchUsers(user,page,size);
    }


    public User saveUser(User user){
        User save = userService.save(user);
        return userService.save(user);

    }

    /*public User updateUser(User user){
        User save = userRepository.save(user);
        return userRepository.u(user);
    }*/




}

service:

@Component
public class   UserServiceImpl implements UserService{
    @Autowired
    UserRepository userRepository;

    @Override
    public List<User> findSearchUsers(User user,int page,int size){
        if (page==0){
            page = 1;
        }
        if (size==0){
            size=20;
        }
        Specification<User> mapwarp = createSpecification(user);
        PageRequest pageRequest =  PageRequest.of(page-1, size);
        List<User> content = userRepository.findAll(mapwarp,pageRequest).getContent();

        return content;
    }

    /**
     * 动态条件构建
     * @param user
     * @return
     */
    private Specification<User> createSpecification(User user) {
        return new Specification<User>() {
            @Override
            public Predicate toPredicate(Root<User> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
                List<Predicate> predicateList = new ArrayList<Predicate>();
                if (!StringUtils.isEmpty(user.getUserName())) {
                    predicateList.add(cb.like(root.get("userName").as(String.class), "%"+(String)user.getUserName()+"%"));
                }
                return cb.and( predicateList.toArray(new Predicate[predicateList.size()]));

            }
        };

    }
}

jpa:

public interface UserRepository extends JpaRepository<User, String>, JpaSpecificationExecutor<User> {

}

entity实体类：

@Data
@ToString
pulic class User{
    private String userId;
    private String password;
    private String userName;
    private String userSex;
}

graphql 配置文件：
蓝色字体与方法名保持一致

type Query {
    findSearchUsers(user:inputUser,page:Int,size:Int):[User]


type Mutation{
    saveUser(user:Useradd!):User

}


type User {
    userId: String
    userName: String
    userSex: String
}

input inputUser {
    userId: String
    userName: String
    userSex: String

}

input Useradd {
    userId: String
    userName: String
    userSex: String
}

四、前端查询

http://localhost:8080/graphiql

上面的界面就是graphql的可视化界面，出现这样一个界面已经成功了一大半了

查询用query，修改用mutation

查询

query{
  findSearchUsers(user:{},page:1,size:5){
    userId
    userSex
    userName
  }
}

修改

mutation{
  saveUser(user:{
     userId:""
    userSex:""
    userName:""
  
  })
   
  {
    userId
  }
}

{
userId
}
是可以看返回的id

完结撒花✿✿ヽ(°▽°)ノ✿

本文地址：https://blog.csdn.net/ZraInCyy/article/details/107359066