GraphQL：Spring Boot集成Graphql简单实例

import graphql.ExecutionResult;
import graphql.GraphQL;
import graphql.schema.DataFetcher;
import graphql.schema.GraphQLObjectType;
import graphql.schema.GraphQLSchema;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
 
@SpringBootApplication
public class GraphQLApplication {
 
    @Bean
    public GraphQL graphQL() {
        return GraphQL.newGraphQL(graphQLSchema()).build();
    }
 
    private GraphQLSchema graphQLSchema() {
        return GraphQLSchema.newSchema()
                .query(queryType())
                .build();
    }
 
    private GraphQLObjectType queryType() {
        return GraphQLObjectType.newObject()
                .name("hello")
                .field(field -> field
                        .name("world")
                        .type(GraphQLString)
                        .dataFetcher(helloWorldDataFetcher())
                )
                .build();
    }
 
    private DataFetcher<?> helloWorldDataFetcher() {
        return dataFetchingEnvironment -> "Hello, World!";
    }
 
    public static void main(String[] args) {
        SpringApplication.run(GraphQLApplication.class, args);
 
        ExecutionResult executionResult = graphQL().execute("{ hello { world }}");
        System.out.println(executionResult.getData());
    }
}

这段代码定义了一个简单的GraphQL查询，当Spring Boot应用启动时，它会执行一个简单的GraphQL查询并打印结果。这个例子展示了如何在Spring Boot应用中集成GraphQL，并定义了一个GraphQL类型和查询。