2021-01-27 GraphQL入门（一）

GraphQL

    GraphQL既是一种用于API的查询语言也是一个满足你数据查询的运行时。GraphQL对你的API中的数据提供了一套易于理解的完整描述，使得客户端能够准确地获得它需要的数据，而且没有任何冗余，也让API更容易地随着时间推移而演进，还能用于构建强大的开发工具。

 

启动后界面如上图所示

1.1 添加依赖

1.  
   <dependency>
2.  
   <groupId>org.springframework.boot</groupId>
3.  
   <artifactId>spring-boot-starter</artifactId>
4.  
   </dependency>
5.  
    
6.  
   <dependency>
7.  
   <groupId>org.springframework.boot</groupId>
8.  
   <artifactId>spring-boot-starter-web</artifactId>
9.  
   </dependency>
10.  
     
11.  
    <dependency>
12.  
    <groupId>com.graphql-java</groupId>
13.  
    <artifactId>graphql-java-tools</artifactId>
14.  
    <version>5.2.4</version>
15.  
    </dependency>
16.  
     
17.  
    <dependency>
18.  
    <groupId>com.graphql-java</groupId>
19.  
    <artifactId>graphql-spring-boot-starter</artifactId>
20.  
    <version>5.0.2</version>
21.  
    </dependency>
22.  
     
23.  
     
24.  
    <dependency>
25.  
    <groupId>com.graphql-java</groupId>
26.  
    <artifactId>graphiql-spring-boot-starter</artifactId>
27.  
    <version>5.0.2</version>
28.  
    </dependency>
29.  
     
30.  
    <dependency>
31.  
    <groupId>org.springframework.boot</groupId>
32.  
    <artifactId>spring-boot-starter-test</artifactId>
33.  
    <scope>test</scope>
34.  
    </dependency>

 

1.2 编写graphqls文件

1.  
   type Query {
2.  
   pets: [Pet]
3.  
   animals: [Animal]
4.  
   }
5.  
    
6.  
   type Pet {
7.  
   id: Int
8.  
   type: Animal
9.  
   name: String
10.  
    age: Int
11.  
    }
12.  
     
13.  
    enum Animal {
14.  
    DOG
15.  
    CAT
16.  
    BADGER
17.  
    MAMMOTH
18.  
    OOOOOO
19.  
    }

本人用的idea编写graphqls文件，可以安装graphql插件，

配置文件类型

 

1.3 编写实体类

1.  
   package com.example.demo;
2.  
    
3.  
   public class Pet {
4.  
   private long id;
5.  
    
6.  
   private String name;
7.  
    
8.  
   private Animal type;
9.  
    
10.  
    private int age;
11.  
     
12.  
    public Pet(long id, String name, Animal type, int age) {
13.  
    this.id = id;
14.  
    this.name = name;
15.  
    this.type = type;
16.  
    this.age = age;
17.  
    }
18.  
     
19.  
    public Pet() {
20.  
     
21.  
    }
22.  
     
23.  
    public long getId() {
24.  
    return id;
25.  
    }
26.  
     
27.  
    public void setId(long id) {
28.  
    this.id = id;
29.  
    }
30.  
     
31.  
    public String getName() {
32.  
    return name;
33.  
    }
34.  
     
35.  
    public void setName(String name) {
36.  
    this.name = name;
37.  
    }
38.  
     
39.  
    public Animal getType() {
40.  
    return type;
41.  
    }
42.  
     
43.  
    public void setType(Animal type) {
44.  
    this.type = type;
45.  
    }
46.  
     
47.  
    public int getAge() {
48.  
    return age;
49.  
    }
50.  
     
51.  
    public void setAge(int age) {
52.  
    this.age = age;
53.  
    }
54.  
    }

1.  
   package com.example.demo;
2.  
    
3.  
   public enum Animal {
4.  
   /**
5.  
   * Animal
6.  
   */
7.  
   DOG,
8.  
   CAT,
9.  
   BADGER,
10.  
    MAMMOTH,
11.  
    OOOOOO
12.  
    }

1.4 编写查询组件

1.  
   package com.example.demo;
2.  
    
3.  
   import com.coxautodev.graphql.tools.GraphQLQueryResolver;
4.  
   import org.springframework.stereotype.Component;
5.  
    
6.  
   import java.util.ArrayList;
7.  
   import java.util.List;
8.  
    
9.  
   @Component
10.  
    public class Query implements GraphQLQueryResolver {
11.  
    public List<Pet> pets() {
12.  
    List<Pet> pets = new ArrayList<>();
13.  
     
14.  
    Pet aPet = new Pet();
15.  
    aPet.setId(1L);
16.  
    aPet.setName("Covey's cat");
17.  
    aPet.setAge(3);
18.  
    aPet.setType(Animal.CAT);
19.  
     
20.  
    pets.add(aPet);
21.  
     
22.  
    return pets;
23.  
    }
24.  
     
25.  
    public List<Animal> animals() {
26.  
    Animal animal = Animal.MAMMOTH;
27.  
    Animal animal1 = Animal.BADGER;
28.  
    Animal animal2 = Animal.CAT;
29.  
    Animal animal3 = Animal.OOOOOO;
30.  
    Animal animal4 = Animal.DOG;
31.  
    List<Animal> animalList = new ArrayList<>(4);
32.  
    animalList.add(animal);
33.  
    animalList.add(animal1);
34.  
    animalList.add(animal2);
35.  
    animalList.add(animal3);
36.  
    animalList.add(animal4);
37.  
    return animalList;
38.  
    }
39.  
    }

本章节介绍完，后面待续...

参考资料：

https://github.com/graphql-java/graphql-java-spring

https://www.graphql-java.com/tutorials/getting-started-with-spring-boot/

https://graphql.cn/code/#server-libraries