Question

我正在执行以下代码，结果是：

{TestPojo={id=null, name=null}}

我期待结果为{TestPojo={id="1", name="Jack"}}。我错过了什么？

import static graphql.Scalars.GraphQLString;
import static graphql.schema.GraphQLFieldDefinition.newFieldDefinition;
import static graphql.schema.GraphQLObjectType.newObject;

import java.util.Map;

import graphql.GraphQL;
import graphql.schema.DataFetcher;
import graphql.schema.DataFetchingEnvironment;
import graphql.schema.GraphQLObjectType;
import graphql.schema.GraphQLSchema;

public class HelloWorld {
    public static void main(String[] args) {
        // sub schema to be added to parent schema
        GraphQLObjectType testPojo = newObject().name("TestPojo")
                                                .description("This is a test POJO")
                                                .field(newFieldDefinition().name("id").type(GraphQLString).build())
                                                .field(newFieldDefinition().name("name").type(GraphQLString).build())
                                                .build();
        // parent schema
        GraphQLObjectType queryType = newObject().name("helloWorldQuery")
                                                 .field(newFieldDefinition().name(testPojo.getName())
                                                                            .type(testPojo)
                                                                            .dataFetcher(new DataFetcher() {
                                                                                @Override
                                                                                public Object get(DataFetchingEnvironment arg0) {
                                                                                    Object a = new GrapgQLSampleController()
                                                                                                       .greeting2();
                                                                                    return a;
                                                                                }
                                                                            })
                                                                            .build())
                                                 .build();


        GraphQLSchema schema = GraphQLSchema.newSchema().query(queryType).build();
        Map<String, Object> result = (Map<String, Object>) new GraphQL(schema).execute("{TestPojo {id,name}}")
                                                                              .getData();
        System.out.println(result);
        // Prints: {TestPojo={id=null, name=null}}
    }

    /**
     * service method 2
     *
     * @return
     */
    public TestPojo greeting2() {
        return new TestPojo("1", "Jack");
    }

    // inner pojo
    class TestPojo {
        public String id;
        public String name;

        TestPojo(String id, String name) {
            this.id = id;
            this.name = name;
        }
    }
}

Answer 1

尝试在TestPojo类上添加getter方法，因为在类上声明时会调用这些方法。否则，在该字段上定义您自己的DataFetcher。

class TestPojo {
    public final String id;
    public final String name;

    TestPojo(String id, String name) {
        this.id = id;
        this.name = name;
    }

    String getId() {
        return id; 
    }

    String getName() { 
        return name;
    }
}

Answer 2

通过修复代码来尝试教学。请注意，静态内容来自.staticValue（“X”）

中的任何内容

    GraphQLObjectType testPojo = newObject().name("TestPojo")
                                            .description("This is a test POJO")
                                            .field(newFieldDefinition().type(GraphQLString).name("id").staticValue("Test1"))
                                            .field(newFieldDefinition().type(GraphQLString).name("name").staticValue("pojo1"))
                                            .build();

    GraphQLSchema schema = GraphQLSchema.newSchema().query(testPojo).build();
    Map<String, Object> result = (Map<String, Object>) new GraphQL(schema).execute("{id,name}")
                                                                          .getData();
    System.out.println(result);

将打印{id = Test1，name = pojo1}

有空时可以使用DataFetcher更新示例

GraphQLObjectType的Hello世界

2 个答案: