<dependency>
    <groupId>com.graphql-java</groupId>
    <artifactId>graphql-java</artifactId>
    <version>11.0</version>
</dependency>

/**
 * 簡(jiǎn)單展示 GraphQL的查詢(xún)，以及通過(guò)JavaAPI響應(yīng)數(shù)據(jù)
 */
public class GraphQLSimpleDemo {


    public static void main(String[] args) {
        // 定義數(shù)據(jù)響應(yīng)對(duì)象
        GraphQLObjectType userType = createGraphQLObjectType();
        // 根據(jù)定義的數(shù)據(jù)響應(yīng)對(duì)象構(gòu)建響應(yīng)的數(shù)據(jù)
        GraphQLFieldDefinition userDefinition = createGraphQLFieldDefinition(userType);
        // 創(chuàng)建查詢(xún)響應(yīng)
        GraphQLSchema graphQLSchema = createGraphQLSchema(userDefinition);
        GraphQL graphQL = GraphQL.newGraphQL(graphQLSchema).build();

        // 查詢(xún)語(yǔ)句
        String graph1 = "{User{id, name}}";
        // 查詢(xún)多個(gè)字段
        String graph2 = "{User{id, name, age}}";

        // 執(zhí)行查詢(xún)
        ExecutionResult execute = graphQL.execute(graph1);
        // 獲取結(jié)果
        System.out.println(execute.toSpecification());

        // 執(zhí)行查詢(xún)
        ExecutionResult execute2 = graphQL.execute(graph2);
        // 獲取結(jié)果
        System.out.println(execute2.toSpecification());
    }

    // 創(chuàng)建GraphQLSchema
    public static GraphQLSchema createGraphQLSchema(GraphQLFieldDefinition userDefinition) {
        GraphQLObjectType userQuery = GraphQLObjectType.newObject()
                                                               .name("userQuery")
                                                               .field(userDefinition)
                                                               .build();
        return GraphQLSchema.newSchema().query(userQuery).build();
    }

    /**
     * 創(chuàng)建GraphQLFieldDefinition對(duì)象
     *
     * 根據(jù)定義的查詢(xún)對(duì)象做真正的查詢(xún)，返回查詢(xún)數(shù)據(jù)
     *
     * 這里使用靜態(tài)對(duì)象構(gòu)建數(shù)據(jù)，如果是查詢(xún)數(shù)據(jù)，可以在這里進(jìn)行做查詢(xún)
     *
     */
    public static GraphQLFieldDefinition createGraphQLFieldDefinition(GraphQLObjectType userType) {
        return GraphQLFieldDefinition.newFieldDefinition()
                .name("User")
                .type(userType)
                // 靜態(tài)數(shù)據(jù)
                .dataFetcher(new StaticDataFetcher(new User(1L, "測(cè)試", 10)))
                .build();
    }

    /**
     * 定義GraphQLObjectType對(duì)象
     * 該對(duì)象是用來(lái)做查詢(xún)響應(yīng)對(duì)象的名稱(chēng)和查詢(xún)的字段的定義
     */
    public static GraphQLObjectType createGraphQLObjectType() {
        return GraphQLObjectType.newObject()
                .name("User")
                .field(GraphQLFieldDefinition.newFieldDefinition().name("id").type(Scalars.GraphQLLong))
                .field(GraphQLFieldDefinition.newFieldDefinition().name("name").type(Scalars.GraphQLString))
                .field(GraphQLFieldDefinition.newFieldDefinition().name("age").type(Scalars.GraphQLInt))
                .build();
    }

}

/**
 * 簡(jiǎn)單展示 GraphQL的查詢(xún)，以及通過(guò)JavaAPI響應(yīng)數(shù)據(jù)
 *
 * 傳遞參數(shù)進(jìn)行查詢(xún)
 */
public class GraphQLSimpleDemoWithArgs {


    public static void main(String[] args) {
        GraphQLObjectType userType = createGraphQLObjectType();
        GraphQLFieldDefinition userDefinition = createGraphQLFieldDefinition(userType);
        GraphQLSchema graphQLSchema = createGraphQLSchema(userDefinition);
        GraphQL graphQL = GraphQL.newGraphQL(graphQLSchema).build();

        String graph3 = "{User(id:1){id, name, age}}";
        ExecutionResult execute3 = graphQL.execute(graph3);
        // 獲取結(jié)果
        System.out.println(execute3.toSpecification());
    }

    // 創(chuàng)建GraphQLSchema
    public static GraphQLSchema createGraphQLSchema(GraphQLFieldDefinition userDefinition) {
        GraphQLObjectType userQuery = GraphQLObjectType.newObject()
                                                               .name("userQuery")
                                                               .field(userDefinition)
                                                               .build();
        return GraphQLSchema.newSchema().query(userQuery).build();
    }

    /**
     * 創(chuàng)建GraphQLFieldDefinition對(duì)象
     *
     * 根據(jù)定義的查詢(xún)對(duì)象做真正的查詢(xún)，返回查詢(xún)數(shù)據(jù)
     *
     * 這里使用靜態(tài)對(duì)象構(gòu)建數(shù)據(jù)，如果是查詢(xún)數(shù)據(jù)，可以在這里進(jìn)行做查詢(xún)
     *
     */
    public static GraphQLFieldDefinition createGraphQLFieldDefinition(GraphQLObjectType userType) {
        return GraphQLFieldDefinition.newFieldDefinition()
                .name("User")
                .type(userType)
                // 設(shè)置參數(shù)查詢(xún)數(shù)據(jù)
                .argument(GraphQLArgument.newArgument().name("id").type(Scalars.GraphQLLong).build())
                .dataFetcher(environment -> {
                    Long id = environment.getArgument("id");
                    return new User(id, "name" + id, id.intValue());
                })

                .build();
    }

    /**
     * 定義GraphQLObjectType對(duì)象
     * 該對(duì)象是用來(lái)做查詢(xún)響應(yīng)對(duì)象的名稱(chēng)和查詢(xún)的字段的定義
     */
    public static GraphQLObjectType createGraphQLObjectType() {
        return GraphQLObjectType.newObject()
                .name("User")
                .field(GraphQLFieldDefinition.newFieldDefinition().name("id").type(Scalars.GraphQLLong))
                .field(GraphQLFieldDefinition.newFieldDefinition().name("name").type(Scalars.GraphQLString))
                .field(GraphQLFieldDefinition.newFieldDefinition().name("age").type(Scalars.GraphQLInt))
                .build();
    }
    
}